Home and heating

I’ve recently bought a house which has solar panels already installed (no battery storage) along with the FiT Scheme. I have transferred ownership and I just have a few general/basic questions regarding the solar panels/FiT scheme. I’m only querying this as my neighbour in the same size house/same number of occupants (2 adults) is roughly £40 a month cheaper than us in energy bills without solar panels. I have just submitted my first generation reading to OVO and will receive my first payment in December. OVO have said that I am paid for any excess energy that I generate. Are the solar panels directly powering some appliances in my house and if so why don’t I see the benefits on my energy bill? On average we use roughly 380kW per month and have a smart meter just for our electricity. Apologies for the basic questions, I just want to make sure I understand it all before selecting our new tariff. Thanks

Hoping someone here can help because this has been an on-going battle since before OVO took over SSE and it’s gotten progressively worse recently. I live in a house that’s meters haven’t been checked, inspected, whatever since at least 1993. I have two meters - one for my storage heaters and water tank, and one for standard electricity. I’ve been trying to get this changed to either a smart meter if available OR just a standard single meter with a day or night rate. I have email chain(s) going on with SSE/OVO (One email chain is using @sseenergyservices.com and the other is @ovo.com hence posting here) that I seem to just be going around in circles. I finally got through to the Electric Heating Team (EHT) about two weeks ago who changed me onto a single rate THTC tarrif, so both my standard and heating meters are at the same rate - but based on the readings that I’ve been providing, it’s still nearly 500 a month just for two storage heaters and a water tank. Has anyone else had problems being switched to a single meter? It’s driving me insane and I can’t change providers even if I wanted to because I’m currently bent over a barrel with an old meter system that they won’t change that no one else supports. Edit: Just to add, it’s Radio Teleswitch Total Heat Total Control (THTC) to be specific.

It may be helpful for customers to see how their own energy consumption compares with other people’s in similar circumstances, possibly even prompting a change in behaviour in order to keep up with the Joneses. OVO now provides two options for seeing this comparison: under Energy insights in the online account, and under Usage in the shiny new app. I don’t really expect my usage pattern to match anyone else’s, because I don’t expect there are many more just like me in this part of the world. However, I would expect the ‘similar homes’ to be reasonably similar in the two places. Sadly, they’re wildly different: Usage in kWh per weekA click on the image should bring up a more legible version The divergence between my own usage pattern (the green bit) and everyone else’s is difficult enough to explain, but I put it down to my being eccentric 🙂. However, the variance between the blue fields is quite striking, and indicates that there are totally different parameters applied to arrive at an average value for homes similar to mine. About the only thing they have in common is a decline from January to May - surprise, surprise! There may be some smoothing applied to the light blue curve, to minimize the distortion that short-lived events like Easter would otherwise introduce. But that OVO Beyond’s figures are consistently significantly higher than those from the web indicates a more fundamental disparity between the datasets behind the figures. I’ve been told that OVO Beyond looks only at properties in the same (DNO) region; has anyone else, perhaps in other parts of the country, been struck by this dissimilarity of allegedly similar homes?

We’ve very recently had an air sourced heat pump (ASHP) fitted and there are lots of gems on the forum (and elsewhere) which I have been looking at to remind me of some key things to consider. There are a few items which I can’t see an answer to and as yet don’t know the pros and cons about. Circulation pump - on demand or continuous? Heating - set a schedule or not? Setback - useful overnight or not? Quiet Mode - does this affect efficiency? DHW - schedule and reheat or just schedule? I realise a few things are personal preference but there will be some who have more knowledge from experience.

Updated on 21/01/25 by Chris_OVO: Interested in generating energy from the sun? 🌞 Guess what... Thanks to the help of our PV champions and Plan Zero heroes, we’ve put together a collaborative guide to all things solar. Thinking about getting into the micro-generation game but don’t know where to start? - Check out the info below for what you might need to consider before joining the solar panel club. Below is a series of experiences and insights from community members for you to get a different point of view on this energy generating tech. Please note that this is not the viewpoint and advice of OVO. As always, it’s important to do your own research. Check out our Forum guidelines here. How many PV panels do you have, and what type? I have PV panels - 14 of them, styled “8.33 285w ETERNITY+10 PV modules”. They are made by Table Trading S.L. aka 8.33 Solar. I have a 4kW domestic solar PV installation since 2016.· The array is 12 x 330w Panasonic HIT N Hybrid Modules. We chose Panasonic as it came with 25 Year Performance & 15 Year Product Warranty. I have the following equipment fitted for the last 4 years with the FIT paid by British Gas at Feed in Tariff 4.68 p/kWh and Export at 5.50p/kWh giving about £315 last year other years not analysed as I always had better things to do. The system 26 JA Solar 270W Black JAM6(K)(BK)-60-270-4BB fitted on a south facing roof, a Samil Solar River 6000TL inverter and a Landis & Gyr - 5235B meter I’ve been using PV Solar Panels off-grid for about 20 years. I have built a number of devices which can use the DC power directly rather than convert it to 230v AC mains first. There’s no ‘standard size’ for a rooftop solar panel, but they tend to be around 1.6m x 1m and weigh about 20Kg. As I’m using some new panels and some relocated, I’ve stuck with my favoured Panasonic HIT units. Panasonic HIT 340w panels I had solar panels installed in 2011, I have 12 Yingli 235W panels which feeds a Fronius IG 30 Inverter with a 20yr extended warranty, it is cabled down the void my soil pipe runs in to the garage to the Elster generation meter and from there to a 16A MCB in my Consumer Unit. The total peak power rating is 2.8kWp. To date, I have generated 26.58MWh. How are they set up on the property? There’s lots to consider in terms of placement - from the facing and angle of your roof, the impact of shade, to your location in the country: [I have 14 panels], 6 East facing and 8 West facing for the afternoon sun, using a Clenergy mounting kit. 3.99 kW nominal they rarely reach 3 at any time. We’re in Durham in the North East of England, so not ideal for lots of sunshine in comparison to the South of the country. Our best day this year was 1 June at 25.6 kWh; our highest peak generation was 2 Jun at 2.87 kW. Fortuitously my renovated Devon farmhouse has an extensive south-facing roof at the ideal angle of 35° Array A is grid-connected The slope of the roof is almost important as its orientation towards south Here’s a diagram from an excellent online tutorial published by Viridian Solar in Cambridgeshire This might be a good moment to show a diagram which illustrates the amount of energy available from the sun and how this translates into what is achievable using current silicon panel technology. The effect of cloud cover is quite pronounced. Any shading on an array of PV Panels will dramatically reduce the power available. How do your panels work with other equipment in the property such as energy storage, PV diverters, immersion heaters or electric vehicle charging? I have an Optimmersion intelligent immersion heater controller which was installed in July 2014 and after 7 years has paid off 89% of its cost of £300 so will probably take another 7+ yrs to break-even; this is calculated by estimating gas savings from not having to heat water with the boiler. However, there’s a certain satisfaction to getting free hot water and in the summer we turn off the gas boiler and use the hot water the immersion provides. Following the acquisition of my first Nissan Leaf in April 2018 I had a zappi EV charger installed in June 2018 for the princely sum of just under £80 after the government grant and hard won contribution from Nissan. The zappi automatically charged the car when surplus generation equalled or exceeded 1.4kW and was a great device. My experience has been positive so far. I wish we could have more which would then make more sense of a battery. Last time I looked was when we had a power cut, and our panels stopped providing power to us. I was astounded to find that most batteries also just stop working in such a situation. At some stage I will get round to connecting it up to the immersion heater I had retrofitted when I eventually found a plumber who could do it - but I need to find a different installer. We don’t yet have an EV but that could be a battery alternative. Since 2020 I have V2G and SMETS1 which reduced my FIT so I hope the export credits compensate for the reduced microgeneration. My PV Solar Panels are connected to the PowerVault Battery using an AC-input configuration. Let’s calculate this using generous efficiencies of 94% for AC-to-DC (charge) and 90% for DC-to-AC (discharge) cycles. For each 1kWh generated by the PV Panels, 1x0.9x0.94 = 846w ends up in the battery. To retrieve that back into the home I get 846x0.9 = 760w Using this configuration, my three rooftop arrays rated at 5.1kW actually yield just 3.88kW from a period of full sunshine. That’s appallingly bad, and no one would seriously consider such an arrangement if they were aware of the figures. The Storage Battery itself has running costs, mainly for the fans which cool it. My measurements show this is approx 500kWh per year. That equates to around £20 of ‘lost’ SEG payments… which I don’t receive anyway! Since then I have had a Tesla 13.64 k battery fitted about 3 months ago and I have fitted my Energi Eddi and Zappi for hot water production and Car charging from surplus PV energy. My car is a fully electric Kia Niro plus 64 kWh battery, I charge whenever I remember and I have surplus energy and so far approx 2000 miles have only once paid or a charge. On the whole I am delighted with the system performance especial the reduction in grid demand the Tesla has produced. Don’t ask for exact figures, let it suffice to say since the Tesla was fitted in late May I have only used 15 kWhs, so at my present rate not considering the standing charge that’s about £1.80 of electricity, approximately 2 summer months for a couple of quid. Who was your installer and what was the installation experience? Installed October 2015 at a cost of £5995 by a local company called WeRSolarUK (which nearly put me off). Installation was straightforward, all done in a day. The company isn’t operating and their web site isn’t there, but hasn’t been struck off or shut down according to companies house. The installation included an EPC, rating our house as B 83. The installer was first4solar who were responsive and professional till the point of invoice settlement. Unlike many suppliers, they remain an ongoing concern. My concern remains the longevity of the solar panels which is indirectly proportional to the installers/companies survive in the business. The ROI or risk to reward is disproportionate especially with the FIT now gone. This issue needs highlighting here for any others contemplating grid-connected PV Solar Panels. You are completely dependent on the installers adequately providing documentation. Once equipment is fitted and any invoices paid, you lose all leverage to get this sorted. It’s worth checking out the MSC website , they’re able to help find an installer who can provide the necessary certification to allow you to apply for export payments via the Smart Export Guarantee and advise what to do if you’ve got already got panel installed but don’t yet have the required documentation. What is the income or saving you make and what is your expected return on investment? The predicted performance was 2640 Kwh (sic) pa. Actual is 15140 kWh over 5 years, so 3028 pa. I’m on the FIT scheme, starting at 12.47p for generation and 4.85p for export. When installed we had dumb meters, but in 2017 got smart meters so the export was more accurate. Regrettably I still have to submit the readings to OVO manually. Since installation, export is almost exactly half generation. Some days our electricity use is negligible during the day. So far saved electricity over 5 full years has been worth £999, based on units used compared to pre-solar. FIT payments have been £2545, so between those it has paid off more than half already. The estimate at the time of installation was [around 8 years, which is in line with the observed performance] The estimated savings was (forecasted to be) about £450 per year with an estimated ROI over 11+ years so yet to recover the investment. As of now, generated 18kWH of electricity so roughly £2600 of savings achieved in the last 7 years. On day one, I created a spreadsheet and recorded the generation every day with the aim of moving to weekly or even monthly…..I’m still doing it daily! I then compared the total cost of the system (£12710.31 inc. extended warranty on inverter) with the total income generated. I have a daily record of generation since 2011 compared to the estimated generation, also monthly and annual generation compared to estimated generation and also the weather on the day, graphs of annual generation compared with the original estimate, graphs showing all years cumulative generation, table of monthly generation and payback, a table of FIT payments. I feed my data into a website https://pvoutput.org which allows you to choose favourites and compare your output against theirs and I have to say mine holds up very well against some larger systems. What needs to be considered in terms of maintenance? They keep remarkably clean - I’ve twice washed them with a long handled brush attached to the garden hose. They are tight enough to the roof that we don’t get birds underneath. A roofer we used recently commented on that as he’s previously come across birds nesting under panels, even a pigeon! Should maintenance be needed on your set up, and the original installers were no longer in business, I’m assuming another installer would be capable and qualified to do the work? I hope so! SolarEdge still have lots of links to approved installers, so although my installer has gone, I hope it wouldn’t be difficult. There is at least one nearby that will do a service for £75, and specifically state “We will service your system, even if we didn’t install it”. How is your exported energy measured and how do you take/submit these readings? We have report PV figures manually each quarter (M, J, S, D). The reading from the generation meter indoors, and the EXP KWH from the "smart" meter outside (press 9 and wait for the phrase to show followed by the number). The IHD isn't any use for this. The instructions specifically said we cannot use the export reading from the generation meter. The payment takes almost 2 months. Prior to getting the smart meter our export was estimated at 50%. It has actually been around that in winter but over 70% for the two summer quarters. Apparently SMETS2 might be able to report the EXP KWH but I'd still have to report the generation reading. The OVO Guide to smart meters states : If you have a SMETS1 meter, a remote software upgrade will enable it to work across the same network used by SMETS2. That means it will be migrated onto the national smart meter network - but I don't imagine it will enable SMETS2 functionality. I don't know any technical details of the generation meter, but it was installed with its own big off switch next to the existing consumer unit aka fuse box. SMETS1 meter followed by generation meter. What software is available/included to help monitor the energy you create? The inverter manufacturer [SolarEdge] provides the web/app interface to monitor generation and state that it will be there for the lifetime of the installation without ongoing cost. Solaredge claim to be The World’s #1 Home Solar Energy System. The app has been updated several times since 2015, as has the web site. The company seems forward thinking and active in homes and businesses round the world. App information with comparisons peak momentary production The software and monitoring system is my second bugbear. There is no standard platform to collect, share and analyse data. I think this could be a great opportunity for Kaluza like apps to integrate microgeneration with grid load balancing. What about Solar Thermal panels? I’ve a friend who has just had her Solar Thermal Panels aka Solar Water Heating removed from an unshaded south facing roof. She had them installed around 15 or 20 years ago, in the hope that it would reduce her climate impact. Whilst it did give hot water so that she did not need to heat it in summer, and it helped a little even in winter, it never came close to cost effective. There was an ongoing cost to maintenance that reduced the benefit, and payback would have been far longer than their life. Her roof needed retiling, and the cost of removing and refitting was prohibitive. Sorry I do not have actual figures. I have abandoned any idea of such panels due to the cost which was quoted locally at £6000 to include a larger hot water cylinder that might have fitted into the airing cupboard, and our East/West roofs which would have limited any benefit. Cost of heating water is at present £8-£9 per month based on the amount of gas used in each of the summer months. Suggested savings were around £60 for a full year. There would have been a benefit from Renewable Heat Incentive (RHI) but the system would have to be installed and the RHI applied for before midnight on 31 March 2022. What’s the best way to store the energy my Solar panels generate? Solar storage options are discussed at length in these related topics: There’s some more in-depth advice in the comments below. We’ll also be separating some of these into a PV self-installation guide by none other than Plan Zero Hero, @Transparent - for those who might be up for some DIY. Any more questions we haven’t covered or just need a bit of advice from our community experts? - Join in the conversation below, we’d love to help others on their energy-generating journey.

Hi everyone, I recently received a quote from Project Solar for a solar panel installation, and I'd love to get some insights from those with experience in the industry or homeowners who have gone through a similar process. Here’s what’s included in the quote: 🔹 12 Evolution Maxima 490W panels🔹 8.6kWh FOX Energy Cube battery🔹 Full installation🔹 Lifetime Solar Panel Warranty🔹 Lifetime Inverter Warranty (Twin Tracker Inverter)🔹 15-Year Battery Warranty💰 Total Cost: £10K As I'm new to this and just started R&D around this and love to move towards green energy.Does this seem like a reasonable price for the system and warranties provided? Are there any specific things I should watch out for? or good to proceed with this? I’d really appreciate any advice or feedback! Thanks in advance. 😊☀️

We recently in Dec 2021 had a large PV solar install completed on our house. A new 24 panel [385W each] Solar array at 8kW by a seemingly professional company. Disappointingly the install has issues, the main one being that the house utilty meter has the same consumption rate as before the solar install started! This suggests there is wiring config . or equipment fault issue somewhere or the meter cannot cope with Solar supply since we are having large Solar Yields! Either way we are none the closer to getting either the solar installer coming back to fix it in a hurry [I don’t think they understand it!] or the Utility company to check the meter! All this in rapidly rising energy prices ….. pause to weep …… seriously this is cry for help please, we have spent a fortune for nothing! One thing that stands out to me, being a lighting engineer [as a I have some electrical knowledge - although a little knowledge can be a dangerous thing!] is that the Solar Installer has wired the Solar Arrays Inverted 240V output not direct to our Consumer Board but has put it through our Utility Meter with the grid supply [on a single split combined cable]. When I asked the solar installers engineer how the Utility Meter can tell the difference between electricity we are consuming direct from the grid or through the Solar he just shrugged his shoulders and exclaimed that it just can! Personally rightly or wrongly i am unconvinced! I attach an image of our electrical utilty meter [ a SMET 1 – Elster AS300P] cupboard with the solar installers wiring config displayed. Please the question to those in the know is should the Solar always be through the consumer unit first [as in schematic A] or through the utilty meter [as in schematic B] shown , or does it depend on other factors? Any help or direction most welcome.

I had my THTC meter removed and replaced with a smart meter 7 weeks ago. I read that it can take up to six weeks for the meter to finish setting up so why is it still not set up? The new smart meter is successfully sending a daily reading of 2 tariffs (Economy 10) which I can see on my account. However I have yet to be billed for last month and this is now 10 days overdue. The old RTS meter also still shows on my account even though it has been removed. This appears to be messing up my account. For example, when I click on Offers, I get the message “A Problem Has Occurred”. I want to get Charge Anytime set up for my EV which was one of the reasons why I was so keen to get the Smart meter installed. I have been so frustrated by the fact that nobody from Ovo can tell me the timeframe for the old meter to disappear from my account and when I might be able to add Charge Anytime. I have even tried to switch supplier in my desperation to resolve this but this is blocked because of the apparent complicated meter setup. I no longer have a complicated meter setup. I have one meter and all my household power goes through this single meter! Please tell me when this will settle and my account will reflect my new meter setup and when I can charge my car at a lower rate.

Updated on 23/01/25 by Abby_OVO If you want to make your home warmer and more energy efficient, we can help. If you’re eligible, you could get a wide range of energy-saving measures installed through ECO4 – from loft insulation to a new boiler, or even high-end tech like heat pumps. You could get a whole package installed, all for free. Check if you’re eligible What is the ECO4 scheme? The UK government’s ECO scheme is designed to help you reduce your energy bills, keep your home warm and your energy use down. All large UK energy suppliers take part in the scheme, which aims to improve your home’s Energy Performance Certificate (EPC) . As part of it, we at OVO can help you install energy efficiency measures such as insulation and heating upgrades. We’re now on version 4 of the scheme – that’s why it’s known as ECO4. Since the scheme began in 2012, we've helped thousands of homes across the country, with over 600,000 energy efficiency improvements. If your home qualifies for energy efficiency upgrades, our trusted partners could help install the measures it needs. What’s included in ECO4? The ECO funding makes all kinds of different improvements around your home. For example, it’s unlikely you’d only be eligible for loft insulation or a new heating system – you’d get a few things based on a survey of your home. If you join the scheme, you’ll need to agree to all the energy efficiency measures our installation partner recommends when they assess your home. You wouldn’t be able to pick and choose the measures you prefer. These might include: Insulation This is the most important measure we carry out and we make sure all bases are covered: cavity wall, external wall, flat roof, internal wall, loft, underfloor or room-in-roof. Air source heat pump These take warmth from the air outside and use it to heat your home. They power both your heating and your hot water, and they work all year round Electric storage heater upgrade These storage heaters charge up at night. They then release their heat gradually throughout the following day. Solar panels These turn sunlight into electricity, but they don’t even need direct sunlight to work. So they’re perfect for the UK. First time central heating If your home has never had it, we’ll sort this for you. We’ll either fit a modern, efficient boiler or an air source heat pump. Who’s eligible for ECO4? To access ECO4 through OVO, you’ll need: To be a homeowner or a private tenant. An EPC rating of D, E, F or G if you own your home (E, F or G for tenants). Not sure of your Energy Performance Certificate (EPC) rating? Check your EPC if you live in Scotland , or if you live in England or Wales . You don’t need to be an OVO customer. To receive one or more benefits (see below). Eligible benefits Income-based Job Seekers Allowance (JSA) Income related Employment and Support Allowance (ESA) Income Support Pension Credit Guarantee Credit Working Tax Credit Child Tax Credit Universal Credit Housing Benefit Pension Credit Saving Credit Warm Home Discount payment Child Benefit (maximum income levels apply – see below ) Check if you’re eligible How to apply for ECO4 Apply for ECO4 First up, you can apply for the scheme with OVO through our form . We’ll check the details you’ve given us. Then, if it looks like you’ll qualify for ECO4, we’ll pass them to one of our trusted partners. Our partner will contact you They’ll double-check the details you gave us (including your EPC rating and benefits status), and ask some more questions about your home. Then, if you’re eligible, they’ll arrange your home assessment to let you know how it could be improved. Booking the installation Our partner will talk to an installer about the upgrades you could get through ECO4. If you’re happy to go ahead, our partner will book the installations with you. They’ll have their own terms and conditions, and you’ll need to sign a contract with them before the work begins. The order the works happen is decided by scheme rules – for example, insulation will be installed before heating. Check if you’re eligible Important details to know We can’t guarantee you’ll be included in the scheme until our installation partner has confirmed that you’re eligible and that your home fits the ECO4 criteria. We at OVO don’t install the energy efficiency measures ourselves. We’ll put you in contact with one of our trusted partners, then they’ll carry out the full assessment of your home and install any ECO4 measures. The installer will check the information you’ve provided. If it looks like you’re eligible, they’ll need to visit your home to carry out a technical survey to work out which measures to install. Any upgrades they recommend for your home will be based on what will reduce your energy use under ECO4, rather than your preference. Being eligible doesn’t mean that upgrades can definitely be installed in your home. The results of your survey might mean they won’t save enough energy, or installing them could cause a lot of disruption. Or there might be something about your property that means our partner can’t install the measures.

I have a free boiler service included with my plan. The engineer sent a text asking me to book. That was two weeks ago and I've called and sent numerous messages but they aren't responding. I'm very annoyed as I've waited 6 months for the free service. Can I cancel this part of the plan and be compensated as I will now have to call my regular engineer?

Hi. I live in Scotland and had old fashioned storage heaters. I had the flat rewired so the old storage heaters came out and I bought Dimplex Quantum heaters to go in. Meanwhile, OVO installed me a smart meter in January and the engineer who installed it said I’d need to contact OVO to get the new meter upgraded to a 5 port version to accommodate the new storage heaters. Sounded straightforward, but on contacting OVO they now tell me I can’t have a dual rate meter and will have to run the system on the single rate. End of. They are very sorry etc. It’ll be unaffordable! Reading posts on this Forum, I can see there are the SMETS2 meters available - so what’s the problem I’m having? Any advice or suggestions very welcome. Thanks

So I've just had a new solar system installed. It's a 9Kw array + a 13.5Kw Tesla Powerwall 3 battery which has an 11Kw internal inverter. The battery is set to allow 80% for the house and 20% for emergency backup. At sunset the battery is 100% full, by sunrise it's still 60% full. We have ample supply to cover all house load overnight and no large consumers on. The battery does not charge from the grid. Nevertheless I have noticed that throughout the night our grid usage shows that we are importing a significant amount of electricity from the grid in chunks of about an hour at a time. This does not look like a switching issue to me. see the picture. The blue parts of the graph is grip imports. It adds up to about 20p a day, equal to £73 a year. I cannot see any explanation for this!

We had a smart meter installed Aug 24 and at the same time moved from the THTC tariff to the standard variable dual rate tariff (replaced storage htrs with air source heating). I spoke with customer services last week to understand what tariffs were available to us and it looks like we'd be cheaper on one of the fixed tariffs. The service advisor explained that we'd need to be very sure about moving to a single rate fixed tariff from the dual rate tariff as we wouldn't be able to move back to another dual rate tariff. Can't these new smart meters move between single and dual rate tariffs simply by remote configuration? Thanks 👍

It seems quite straight forward doesn’t it? You stick a thermostat on the tank. If the water is cold you turn on the boiler/heat pump and heat it back up again. What’s the problem? Well if you know where heat is going and where it is being lost you make changes to reduce your losses. So I have an old (ancient?) 160l copper cylinder with around 1” of crumbly foam insulation. It has an additional insulating jacket and recently I have added further insulation (10cm thick Diall insulation roll – the stuff made from recycled plastic bottles). In June I added four temperature sensors at approximately 1/8, 3/8, 5/8 and 7/8 down from the top (this equates to around 20l, 60l, 100l and 140l of hot water above each sensor). I can also measure the indirect coil flow temperatures in and out, and the temperature of the cold water entering the tank. The first thing to note is that water is actually quite a poor conductor of heat. You need strong convection currents or stirring/mixing to get a volume of water to a constant temperature. The following are typical tank temperatures over the day. The tank slowly cools over night, although the bottom of the tank warms slightly from the warmer water above (this could be because of the copper heat exchanger). At 05:45 the top mounted immersion heater turns on for 15 minutes (0.75 kWh input). This warms the top and upper sections of the tank but barely affects the lower and bottom sensors. At around 08:00 I do the morning washing up, and again at 12:30 and 16:00. At 16:30 the boiler is used to heat up the water. The indirect coil occupies the bottom half of the tank. The bottom heats fastest, followed by the lower than upper areas of the tank. By 17:00 the tank is pretty well up to temperature. Since the tank has been effectively heated from the bottom, convection within the tank helps to produce a fairly uniform temperature. In fact the bottom of the tank is only a few degrees cooler than the top. At 18:00 it’s time for a bath. Cold water enters the bottom of the tank “pushing” the warmer water up. Although the bottom has now fallen to 27°C, the lower sensor shows little change and the upper two show virtually no impact. This corresponds to a hot water draw-off of around 60l. 18:30 second a bath is run. The bottom sensor is now close to the cold water inlet, the lower has fallen dramatically and the upper sensor shows a small fall. This total usage corresponds to around 3 kWh of energy. What does this mean regards reducing our energy Standing losses and tank temperature The water tank loses heat all day long. In the winter this supplements the heating, in the summer it is wasted. Modern heat pump ready cylinders quote a daily loss of around 1 kWh (150l) to 1.6 kWh (300l). For an old copper cylinder I guess losses would be around 2 to 3 times this. For my tank, in the above example, the daily losses were around 0.95 kWh (£25.30 per annum). The hotter the tank the greater the losses. There is some debate about how hot (or not) the water should be. Have a read of the Heat Geek article for an in depth discussion. One side of the argument says water should be hot (60 °C) to prevent Legionella. The other, that lower water temperatures (around 43 °C) are safer (less chance of scalding) and are more economic. One other thought. If you use a sterilisation cycle once a week, then by the time the next cycle takes place the contents of the tank will have changes several times over. Lessons: Reduce the temperature of the water in the tank to nearer 43 °C (if you are happy to do so). Only heat the tank when the water is (about to be) needed, use a time switch to match your demand. These two lessons actually work well together. By heating the water just before it is needed you are minimising losses and ensuring that the water you have is at its hottest. Maybe you can turn the hot water stat down a degree or two? How much hot water do you actually need? At the point of use you will generally be mixing hot water with cold to generate a comfortable water temperature. If my tank is at 43 °C then I will probably not mix any cold with the hot. 10l of hot water will fill my 10l bowl. If my tank is at 73 °C then I will mix 5l of hot, with 5l of cold (at say 13 °C) to produce my 10l of warm 43 °C water. A 160l tank at 43 °C will provide 160l of usable hot water. A 160l tank at 73 °C will provide 320l of usable hot water (at 43 °C) when mixed with cold. And your usage 10l – Washing up bowl. 30l – A shower. 70 to 130l – A bath. So a relatively small 160l tank at 43 °C has easily enough hot water for an ample bath. Thermostatic control On our old copper tank the mechanical thermostat is near to the bottom of the tank (about the level of my bottom temperature sensor). It has quite a wide hysteresis (over 5 °C). However because of its position I only need to draw off a small amount of hot water (maybe just 20l), before the cold water that replaces it into the bottom of the tank will trip it. The thermal pocket on heat pump cylinders tends to be around half to two thirds the way down the cylinder (nearer to my lower sensor) so it shouldn’t trip until about one third of the hot water has been run off. Because the indirect coil heats the whole of the tank the position of the thermostat has little impact on the final water temperature. However if the thermostat was further up the tank it would allow for a greater run-off before requesting a re-heat. Of course this also means a smaller reserve of hot water. This also explains why systems might report a relatively cold water temperature, whereas the water drawn from the tank is still hot. Heat up losses When the boiler (or heat pump) turns on it must first heat the water circulating around the system. This hot water then transfers heat, through the indirect coil, to the hot water tank. This gives us several losses: The boiler efficiency say 85 to 90% Heat lost from the pipework (the following was obtained from Copper Tubes – Uninsulated Heat Losses (engineeringtoolbox.com) We have around 5m of 28mm pipe-work to the tank, and 5m of 22mm pipe-work returning to the boiler. At a boiler temperature of around 65 °C that’s around 500W! Heat Loss W/m Pipe Size Temperature difference mm Inches 22 °C 38 °C 55 °C 15 ½ 21 32 45 22 ¾ 28 43 60 28 1 34 53 76 35 1¼ 41 64 89 A quick rule of thumb: Power lost = 0.05 * pipe diameter (mm) * temperature difference * pipe length (m) The longer the boiler is running or the hotter the flow temperature the greater the losses. Current installations require the pipe-work to be insulated to reduce these losses, alas mine are un-insulated. Assuming a 30 minute heat cycle (7 kW providing around 3 kWh into the tank) this is around 0.25 kWh Heat retained in circulating water When the boiler turns off hot water will still be present in the pipe-work and boiler heat exchanger. Even with insulation it is likely that most of this heat will be lost. If the boiler has pump over-run the water should be nearer the tank temperature, without it, nearer the boiler temperature. Our pipe-work holds around 5l, and the boiler heat exchanger around 3l, equating to a loss of around 0.3kWh. If the flow temperature is lower the retained heat will be less but, given it will take longer to heat the tank, the pipe-work losses may be greater. If you are relying on the hot water tank thermostat near the bottom of the tank then you really are wasting money! Run off of 20l of water requires around (20l * 4.18 * (43-13) / 3600) ~ 0.7 kWh Losses water & pipe-work losses ~ 0.4 kWh Boiler efficiency 90% Power Used 1.22 kWh / Power into tank 0.7 kWh = 57% efficient. Worth it? Extra boiler cycles (2 per day) * 365 * 0.4 kWh = 292 kWh = £21.30 Boiler cycling and minimum boiler power So the boiler heats the circulating water which in turn heats the water in the hot water tank. As the tank heats up and temperature difference between the circulating water and the tank falls so less heat is transferred to the tank. The boiler must modulate down. If the minimum boiler (heat pump) output exceeds the demand then eventually the boiler must turn off. The circulating water slowly gives up its heat and eventually it cools sufficiently for the boiler to turn back on. However if the tank temperature is such that the return temperature cannot cool enough to turn the boiler back on then the systems gets stuck. The water continues to circulate at the tank temperature (and the tank slowly cools down). The only option is to increase the boiler temperature. In the above, a boiler set-point of 57 °C would seem to be enough to heat the tank to 50 °C, but the boiler hysteresis is around 14 °C, so when the tank reaches 43 °C the boiler cannot turn back on. Only when the boiler is set to around 66 °C can it manage to get the water tank to above 50 °C. The boiler set-point needs to be at least 15 °C above the required water tank temperature. In the post Heating your home – (Correct) Size is important I discussed why too large a boiler (and heat pump) can be detrimental to the performance of your heating. The same is true for the hot water. You can also get boiler short-cycling if the boiler peak output is too large. Because my boiler’s minimum output is 7 kW, once this exceeds the power transferred to the tank the boiler must turn off. During the cooling period the circulating water temperature approaches the tank temperature and the heat transfer falls further. If the boiler could modulate down further it would spend longer heating and hence actually heat the water tank faster. Usage Losses All of the above relates to how to operate your hot water heating. Whenever you use hot water, then hot water is left behind in the pipe-work. It’s easy to work out how much. Wait for a reasonable time since the last time you operated a tap (several hours to let the water cool), then run the tap into a measuring jug, with a finger in the water stream. When it starts to run hot you can note the volume. This is about 2l for our kitchen tap. With hot water at 43 °C this equates to around 0.07 kWh With hot water at 60 °C this equates to around 0.11 kWh Worth the effort? Say 3 bowls of water per day, 365 days, 0.04 kWh = 44 kWh = £3.20 Again running the tank at a lower temperature reduces these losses. Summary Run your water tank at the lowest temperature you are comfortable with based on usage and/or concerns about Legionella. Use a timer to heat your water (just) in advance of when you need it to minimise the number of heat cycles in the day and maximise the water temperature. There is no need to have a tank of hot water sitting unused over night. Match the (minimum) boiler/heat pump output to the tank. A larger tank heat exchanger can’t hurt. Too large a boiler can take LONGER to heat your hot water Allow for hysteresis. Set the boiler temperature around 15 to 18 °C hotter than the target hot water temperature. If you have a choice of bathrooms/toilets use the one nearest the hot water tank.

I changed from an old THTC PAYG meter on 17 January to a smart meter. My understanding is that I would automatically become a credit pay monthly customer at the time of meter change. Since then I have not had a bill although standing charges are being applied to my account. I have also not added any credit to account. I understand that a billing hold will have been placed on my account. How long do these holds last and what must I do to get an accurate bill from OVO? Repeated calls and live chats have been of no help.

I’ve only just read my bill for 1st Dec 24 - 1st Jan 25, and realised that my USAGE for this period was higher than 12 months prior, despite me now having an electric cooker; the gas central heating was turned off for 9 days whilst I was away for Christmas and New Year. I did find a gas leak in early January which OVO had shut off for me (I’m disabled) until the Council found the fault; could this be the cause? If so, could I claim it back off OVO/ the landlord? 2. Why is my smart meter showing the same usage, reporting it as for a cooker, as it did when I had a gas cooker, when I have zero gas appliances in my house? I’m confused/skint!!

Yesterday I got an email from tado, telling me that “As a thank you for being with OVO and tado°, we are giving you a 40% discount in the tado° shop. It will be deducted automatically at the checkout. Complete your tado° home with more Smart Thermostat Add-ons and heat each room individually. Save more energy and money. ” That brings one down from £74.99 (which always seemed ridiculously expensive) to £49. But when I look on Amazon, and in the tado branded shop there, all single smart TRVs are 47% off at £39.99. So the email offer at £49 after discount isn’t good. Even on a 4-pack it is £162 compared to £159.96 . Please OVO stop tado from making special offers that are anything but special! We already have TRVs (not smart but set to different temperatures) and I can’t see how they’d save me enough to recover that outlay, which would only cover the 4 bedrooms. I’ve searched the forums, but cannot find anyone posting about their experience and any actual benefits from using Tado TRVs linked to their tado controller. I’d love to learn from any other’s experiences.

Updated on 07/12/23 by Emmanuelle_OVO: We’ve got an introductory guide to who to contact for each part of your meter and related equipment: Need to book an appointment with OVO for a maintenance job or engineer appointment, check out this topic for job list and prices: For a more technical breakdown check out the user guide made by one of our Community Members below 😊 . The Meter Operation Code of Practice Agreement (MOCOPA) is between the UK’s Energy Suppliers and the Distribution Network Operators (DNOs). The Agreement includes a document which classifies the way in which faults and non-compliances can be identified. It is well written, with numerous photographs. It includes this excellent diagram, showing who is responsible for what in the area of your electricity meter: The Agreement identifies faults with the Distribution Board (DB) equipment, which are the responsibility of the DNO. These are divided into three broad categories: A: Emergency. A life threatening situation and requiring immediate action. B: Remedial work required. Serious, requiring attention for safety reasons, but unlikely to cause a threat until it can be resolved. C: Asset Condition; Requiring attention because it isn’t to the current standards. Thus, by way of example, Code B11 Flow is a reporting category which prevents a Meter Installer from undertaking the work because there is a fuse on the Neutral supply as well as the Live. Old Distribution Board equipment. Sometimes there isn’t actually a fault, but your house appears to have old-style devices belonging to the DNO. The Energy Networks Association publishes another guide with similar format, which enables such items to be identified. The Cut-out Types and Ratings Guidance has full colour photographs and the date range when that equipment was fitted. When viewing items of electrical equipment in your home, it is important not to tamper with it. If in doubt, take a photograph and post it here on the F o r u m for us to see.

I have recently moved into a new property that uses a heat pump. It seems very energy “heavy” at the moment. I check the readings hourly and use around 10kw every hour as things stand at the moment. The system is set to run 2 zones and both zones make use of the consumption curve. House is not boiling warm but is confortable around 10deg but just cannot see why the pump runs 24/7 non stop. Any advice would be much appreciated. Is it standard to use so much energy on the heatpump on cold days and does this alwyas run 24/7.

Hi all, Could some kind person please explain to be if i am misunderstanding something here. When I use the OVO app or the web aplication (I get the same figures) if I compare the daily usage for a given day the figure is wildly different between the “Month” view; 13.11kwh and “Day” view: 45.66kwh. Please see the screenshots for 2nd Jan. This is not an isolated day, every day is similar in the disparity. My bill is based on the lower figure 13.11kwh and on top of that OVO then discount with the Heat Pump Tariff so the amount I pay becomes even less. If you compare the amount my Heat pump uses 30kwh and the daily consumption figure from our Solax inverter (44.52kwwh) it would seem the higher figure is the correct one. How is this possible, anyone got an explanation please?

I have an ecodan heat pump in a new rental. Currently spending up to 50kw some days to keep house warm. 2 zones. Upstairs zone 1 radiators. Downstairs zone 2 underfloor heating. Underfloor set to 19.5 and upstairs radiators set to 19.5. More than happy with heating in the home, but not sure how to drive down the usage? Compensation Curve came to mind, but not sure what would be the most optimal settings. HW come on 2 times a day to heat to 49deg C and thats about it. Any advice would be much appreciated.

Updated on 22/01/25 by Chris_OVO Advantages and Disadvantages of Air-Source Heat Pumps (ASHPs) - Share your experience As one of the leading options in our journey to decarbonising the way we heat our homes, Air Source Heat Pumps (ASHPs) are really heating up (pun intended) and generating much discussion, both amongst the AHSP trialists here on the OVO community and in this recent article written by our content team covering both the advantages and disadvantages of this low carbon heating set-up. We know a lot of you here have gained first-hand experience of life with an ASHP in 2021 and we want to give you another chance to share your stories and help others considering an ASHP installation in 2022 and beyond! As the article outlines one of the main benefits of opting for this heating system over alternatives will be it’s green credentials: “They don’t give off any nasty carbon emissions” How important was this as a factor in making you decide on an Air-Source Heat Pump and how do you think the positive environmental impact could be supported? @nealmurphy, @M.isterW - be honest here: did reducing your home’s carbon footprint play a factor in your choice to go for a heat pump? We know, as with any new technology, there might be some misconceptions about ASHPs which could be putting off other potential adopters. Have you heard the one about how noisy heat pumps are?: “They can make noise – but not as much as you might think” We’ve ‘heard’ that the noise of an ASHP hasn’t been the issue you might have been led to believe before getting one installed - isn’t that right, @James_N and @jason.lewis? Can you dispell this myth once and for all?! Was this a concern you had before the installation and if so what put your mind at ease when giving the go ahead to the install? What would you say to others who might be concerned by the noise factor? Are there times that the pump might be louder than others or is it a constant hum? Cost is always a major factor when making home improvements and could be the deciding factor for some. As the guide calls out, currently installation costs for ASHPs are much higher than for a standard gas boiler replacement: “They’re more expensive to install than a boiler” Whilst I know many of you here are participating in a trial so didn’t incur these installation costs, there may be other financial impacts to consider such as the ongoing running costs. This can be complicated to work out, but is essential information. @Gingernut49 and @hambrook - What advice would you give to someone trying to calculate the affordability of an ASHP over other options? For those considering an ASHP in future there’s some positive news ahead: “You can get some financial support for installing one” We’ve also seen a few community members with ASHPs who aren’t part of any trials that OVO are involved in, and we want to hear from you on this one! @Heatherd, @plodder, @Sean T, @Graham110011, @Roy_and_Becky and @PNorman - Did you get any financial support towards your installation or running costs? Any top tips for someone thinking of applying for this now? “You’ll need proper insulation to get the best out of your heat pump” This is another big and complex factor to consider when changing from a gas boiler to an ASHP. Pipe insulation is one thing, loft insulation is another and the overall heat retention properties of a house can impact the cost effectiveness. @hydrosam and @Transparent @hambrook - How can someone work out whether their house is suitable for an ASHP or what changes might be needed first? Better to get an expert in, or reaching for the thermal sensors? @juliamc we know you have first hand experience of some DIY insulation post-install: looking back, any tips you can share on how to go about this, or would you now advise the installer takes a lead? And what about radiator sizes? - @sylm_2000 we know you had changes made: Share your overall lessons for someone unclear on whether their radiators are fit for purpose in an ASHP home of the future! Potential heat pump owners, over to you! As it’s usually the largest contributing factor in the carbon impact of a household, making such a radical change to the way we do things (over 85% of UK homes are currently heated by gas) will no doubt generate plenty of questions. We’re hopeful that by having honest and constructive communities (like this one!) on hand to de-mystify the process, this will give others the confidence to take the leap - @Jeffus and @Gum168, we know you’re both eco-minded but yet to invest in an ASHP- Has participating in discussions here altered your view of heat pumps or encouraged you to learn more? What would be the number one thing you’d want to know before making the ASHP journey?

I have a new smart meter and I’m newly on Economy 9. I have 4 newish Dimplex storage heaters. One is larger and a medium one and two smaller ones. As well as an immersion water heater. The meter replaced a faulty meter which was preventing the correct tariff working. I’m on pay as you go However I’m finding that it’s costing usually over £10 a night. I have checked and the majority of this is used at night and I can see the usage during the night is approximately £1.25 per hour and then drops to about 10p per hour during the day. It just seems excessive as it’s almost £300 a month for a 2 bedroom house! I have tried switching off the immersion heater or 2 of the heaters but this resulted in no hot water and an expensive reheating of the tank the next night and didn’t really make much difference. I’m assuming that the other heaters then used more electricity because the temperature was lower. No gas in my area Can anyone please help?

Hi all, We built a house and it was finished in 2019. Its to the latest build spec regards to insulation and the likes. Its over 3 levels, ground, first and second floors. Its 5 bedroom, two main baths, a downstairs WC and one en-suite. Downstairs the layout is a kitchen diner, utility with downstairs WC, living room and office. The two bedrooms and one bathroom on the top floor have their radiators all on frost stat upstairs so never come on. The first floor has radiators and 1 thermostat for the entire floor. Its set at 17C in the height of winter and I put it in the bathroom - which the temperature barely can reach. This floor is fully carpeted except the bathrooms which are Amtico vinyl. The ground floor is all UFH, with Amtico vinyl flooring. Each room with a Heatmiser thermostat. Last year (2021) was a mild year. I had the thermostats in the rooms we use (dining/kitchen the living room and the utility set at 18C. The hallway was set at 15C so was the office as we dont use these much or are just pass through areas. We have a Ecodan 11.5kW ASHP with 200L tank. There are 2 adults and 2 children, one 7 and the other 3. The DHW is set at 55C. Last year (2021) we used: DHW: Consumed (kW): 1807 Delivered (kW): 3185 COP: 1.76 Heating: Consumed (kW): 3620 Delivered (kW): 8457 COP: 2.34 2021 was a mild year but in 2020 when we got some real cold weather we used on some days over 75kWs/day, although we had the room temperatures at 21C not 18C. These COP values seem low. We expected at least 3.0 as the yearly average. With bill costs soaring, we are looking at what we can do. The installer isnt really helping at all. Does anyone have advice at all? I have just checked July/August usages: July DHW: Consumed (kW): 84 Delivered (kW): 173 COP: 2.06 Heating: (is this the heater for Legionella) Consumed (kW): 14 Delivered (kW): 0 August DHW: Consumed (kW): 80 Delivered (kW): 164 COP: 2.05 Heating: (is this the heater for Legionella) Consumed (kW): 15 Delivered (kW): 4 (The bathroom t'stat battery failed and called for heating) Thanks in advance.

Hi all, Turns out one of my neighbours has the same econdan heatpump as me. However he is getting much worse efficiency. Annual COP of 2.2 vs mine of 3.0. I checked all the simple settings and it all looks fine. The only difference is that he has underfloor heating, where as I have radiators. Wondering if anyone know is there is a different setting for underfloor heating? many thanks James