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My gas supply is solely for hot water/heating - how is my gas usage so high even when boiler is off?

Forum|Forum|3 years ago
August 31, 2022
62 replies
11142 views

I have a Vaillant ecoTEC Plus 630 boiler paired with a megaflo eco systemfit unvented cylinder. My gas usage is nearly 3 times my colleagues who has a combi boiler (they have a much larger house, more occupants and has a gas hob and oven). My gas usage is solely for hot water/heating. My system is managed through the nest app and my water is heating for a total of 4.5 hours a day (I don’t have hot water whenever I want). I went on holiday for a week, turned my system off and it still charged me for all but 2 days of the 7 I was away. We’ve had no heating on and only the hot water scheduled for the times mentioned above. My usage is around 800-850kWh per month. I live with my boyfriend and two year old. I’ve spoken to so many people who can’t find the issue - can anyone help?! Picture of my usage for the week I was away.

Best answer by Jeffus

Updated on 08/09/25 by Chris_OVO:

Hi @Anders95 I think i would start by getting a boiler engineer to look at your setup. Particularly your controls.

On first inspection it doesn't look like the issue is related to your smart meter given the usage pattern when you are away.

1. We need to see the daily usage page for the gas readings so we can see the 30min readings. Just to check when the gas boiler is firing up. For a day when you were at home, and a day when you think the boiler was off, but it still looks like you used some gas. I think your boiler may be firing up every other day when you are away. It will also help check your boiler isn't on for more than 4.5 hours normally.

2. You have your water on for quite a long time 4.5 hrs. This seems a lot for the size of your household. It obviously depends on usage e..g use of showers and baths., but still that seems high. Especially as you have a modern tank. Do you know the size of the tank? Have you tried reducing the time?

3. I would check the thermostat on the tank to see if it is set at a too higher temperature.

4. I am not convinced the boiler is actually off when you are away. On first inspection it looks like it is still on and firing up every other day for a short time as the water in the tank has cooled down a bit naturally perhaps .

5. It doesn’t look like you have a gas leak as you have a zero reading every other day when you are away. Unless it is something in the boiler when it is turned on. But you would certainly smell the gas leak then if it was happening. So i don't think it is that.

6. Unfortunately with a tank you will end up heating water you don't actually use. You have a modern tank so this will help, but some of the water will cool before you use it. That is not the larger issue you are seeing though i think.

7. There is a small chance you have a leak on one of your hot water pipes from your boiler so you are heating water you are then loosing somewhere. But that doesn't explain the usage pattern when you are away.

8. You could try downloading this app and seeing what is says for your gas readings, especially to see if the app can see your 30min readings.

https://www.glowmarkt.com/

9. You are right, there is no way you should be using 800kWh of gas just for water heating. That would be 9600 kWh a year. A typical house only uses 12000kWh for heating and water according to the ofgem figures and most of that is for heating and not hot water.

Does that help?

Show previous replies

P

Pingu

Newcomer

Not done every single day but still regularly. Some days the usage is very low. I’m not on a direct debit so I understand my kWh prices are slightly more expensive than those who are, but it’s the cost per day that’s concerning me!

BPLightlog

Super User

Ok on the slots when you have a reading a few days apart the daily charge will be estimated but you can take 21 and 22 Nov and the difference is 4 units.
Look on your bill as there is a calculation to convert to kWh from that and then you will have a kWh value to multiply by your unit rate

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}

BPLightlog

Super User

The calculation says something like this ..

It’s easier to check for a months use rather than daily but 4 units would calculate to about 45 which you multiply by your kWh price which at 10p would give £4.50.

One other thought .. do you know if your meter is metric or imperial.. that could be a big difference

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}

juliamc

Rank 20

Did you get your account balance sorted out @Pingu ? I’ve just read back on your previous comments about inputting an incorrect manual reading. @Blastoise186 if Pingu has a smart meter why would they be asked to input readings manually as well ?

BPLightlog

Super User

Did you get your account balance sorted out @Pingu ? I’ve just read back on your previous comments about inputting an incorrect manual reading. @Blastoise186 if Pingu has a smart meter why would they be asked to input readings manually as well ?

The comment above says it’s not connected as the wall is too thick

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}

juliamc

Rank 20

Oh I thought that just meant the IHD didn’t connect to the smart meter. So the smart meter doesn’t send a signal to OVO then ? Hmm.

@Pingu those readings you’ve input show that up to the 15th Nov you were using between 2 and 3 units each day, then from the 15th onwards you were using between 3.6 and 4.5 units per day. So something has changed - most probably the heating being on - though we can’t assign exact amounts to particular days. The OVO system has just given an average from your readings.

S

SarahLock

Newcomer

Hoping for some guidance relating to my situation. I’m a solo tenant in a flat and have found my gas bills extraordinarily high, even considering the energy crisis. Recently I went away for 7 days and turned off my boiler. My gas meter reading was static which proves there was no use in my flat. However on my Ovo account it still showed gas usage for each of these days that I have been billed for. The kWh varied each day. I am concerned I might be being billed for another flat’s usage. When I spoke to Ovo on the phone they suggested that more likely my account calculated an ‘estimate’ usage for each of these days based on my average use rather than an actual reading, but weren’t able to prove this. I'm unsatisfied that a clear explanation hasn’t been provided. Any tips on how I might be able to proceed?

Thanks,

Sarah

BPLightlog

Super User

Hi @SarahLock , and welcome to this customer forum. Estimated bills are quite possible but you can check this yourself by looking on your account

https://account.ovoenergy.com/meter-readings

Alongside the meter readings you will see whether they are recorded or estimated.
If you think the wrong meter is being recorded then you should check the serial number on your account and compare it to that on your own meter. You will see the serial number on the same page online as your meter readings.
A further possibility is if the meter is recording more than it should. This is very unusual but you can check by monitoring the readings over a reasonable time period.

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}

S

SarahLock

Newcomer

Hi @BPLightlog and thanks for your response and help.

The period I refer to was April 8th-14th when I was away. When I look at meter readings there is nothing recorded for those dates (I’ve unchecked ‘hide estimates’), but as you see from graph below there is still an output recorded on the graph. Why would these both suggest different things? The serial numbers are matched correctly.

Many thanks,

Sarah

Jeffus

Rank 20

Hi @BPLightlog and thanks for your response and help.

The period I refer to was April 8th-14th when I was away. When I look at meter readings there is nothing recorded for those dates (I’ve unchecked ‘hide estimates’), but as you see from graph below there is still an output recorded on the graph. Why would these both suggest different things? The serial numbers are matched correctly.

Many thanks,

Sarah