@Dorota Parker Before you sell the flat please can you check these pages as has been suggested above. This will help diagnose the problem:

Can you please post screenshots of these two pages:

https://account.ovoenergy.com/usage?date=2023-09-23&datePeriod=daily&unit=kwh

https://account.ovoenergy.com/usage?date=2023-09-24&datePeriod=daily&unit=kwh

This will show us the usage pattern for a day when you say the flat was empty and the for following day, which showed markedly greater consumption

Thank you. Now I see something new. We came to this flat on 24th of September about 9pm, but we have usage 12AM to 1.30AM? If I have problem with water tank for ex I have usage every 30 min about 0.07-0,08kWh I investigate this now and our tank is off from fuse. and this usage I see when we was not there 4 months but how explain usage on 24th of September night -- nobody came and on something for 1.30 hour. If it was like that each day or each week or each month in this 4 months time was night time usage but is it not. I was looking out coach tickets. We came to Cardiff only about 8.30--9PM, 

Your 23 Sep 2023 energy use

Total Electricity cost

—

Total Electricity kWh

3.59

Before midday

After midday

Need help? You can get support on our help centre (opens in new window) 

This information is exactly what’s needed for detecting how much electricity use has been during each half hour period of the day. You can only get this kind of detail from a smart meter !!! That’s every reason to keep it, and the flat. 

Thank you very much. I am trying to find if it is water tank, because one person here told me that it can be the problem, but you show me another think I do not found it before-, that on 24 of September night I have usage 1,5 hours and in 4 months time I do not have this kind of usage. And it is something different and happen only one time in 4,5 months time.

I will be investigate the cylinder and one day when my child will off all and go to school I will ask her turn off all but the cylinder off but not from fuse. I will see if there will be again 0.08 kWh or not. and the problem will be with cylinder. Water is cold but maybe programmer or something? I am not electrician but I will try to get the answer.

About night usage I have some idea why it happen. Not to trust any more estate agent and left them key. Now I am happy they use our flat only one night on 24th of September. 

Great detective work!!! 

Thanks for posting those figures. 

The table for 23 September shows very clearly that there is something drawing about 150 W running all the time, day and night. That quickly mounts up and it’s costing you more than £30 a month, so you must find out what it is. The tests recommended earlier should help you trace where all this energy is going. You mentioned lights (“Sometime I think that our lights in the building are eat our electricity”) - have you been able to check this?

As for 24 September, you arrived at 9 PM and turned some things on. It looks like heating appliances of some sort drawing about 3 kW; that might have been the oven, the hot water tank and/or electric heaters. None of this would be unusual on a September evening in Cardiff. The big spike at half-past midnight* looks very much like overnight heaters starting up, whether possibly storage heaters or immersion heaters for hot water. 

How is the flat heated? There may be storage heaters (which heat up overnight and then release the heat they contain gradually over the following day), but if there are, the account would normally be set up to buy electricity at a cheaper rate overnight, a so-called Economy 7 tariff. Is this the case? 

If you’re not able to get to the bottom of this now, we would have to see a photo of your meter and the other stuff around it, and a screenshot of your Plan page to tell us what sort of tariff you’re on. 

• It’s very unfortunate that there was at this time a fault in the way the figures were displayed on the Usage page, at least for some customers. It was related to the need to convert times from GMT (used always by the energy industry) to BST (used by ordinary people from March to October). Inexplicably, usage for the last hour of the day was shown as if it occurred during the first hour. The figures you see at the top for 12:00am and 12:30am in fact belong at the bottom, after 11:30pm. This should make more sense: it’s continuing the higher-than-normal usage from earlier on in the evening. 

Thank you very much. I do not have a storage heaters. I am now investigate hot water cylinder. We off all but hot water cylinder we do not off from switch only we off programmer. I think maybe this programmer is not proper fix because it switch is not working- do not off.

I am happy Juliamic find what I do not saw that on 24th I have usage between 12AM and 1.30 AM when nobody must be in, because we came only 8.30-9PM and usage shows that we came that time.

No any item use this electricity, but before we go out in May we gave the key to estate agency and I think somebody was there night time. We made photos before we go and we found something was change and for me was strange to see very dirty sink, specially I left everything very clean.

I like to ask one things please: If usage is from 12AM shows in online account if this electricity was use exactly this time or for ex starts 11.50PM and shows only from 12AM?

That’s shocking that your estate agent appears to have allowed someone to use the property! @Firedog must take the credit for directing you to the information which helped you find the anomaly, and he will be able to answer the question about the time slots.

The timings are exact, to the second. If the energy is used between 11:30 PM and midnight, it will be shown as used in that half-hour slot. 

Please read the footnote in my last post: it explains why you see usage between midnight and 1 AM that shouldn’t be there. That usage in fact took place 24 hours later, like this for the end of 24 September:
  

The electricity being used until you got there in the evening of 24 September was constant at 140 - 160 W. That’s what you should be worried about; the big figures after you arrived show just how much it costs to heat the flat and/or the hot water.

The hot water tank probably has two 3 kW elements, one at the bottom and one near the top. The bottom one makes sure that the whole tank heats up, because the water it heats rises to the top and cold water takes its place ready to be heated. The top one can be used to heat up just enough water for, say, a bath when you don’t need a whole tankful, or when the water has cooled down since it was last heated. It looks like the top one was working before midnight to give you some hot water before the bottom element switched on at 00:30 according to its programme. 

Thank you very much for your help and support. As I wrote earlier, I do not have any storage heaters. All the lights were off and the fridge and washing machine were unplugged.
I'm not there, so I give instructions to my daughter to find out what the problem is, but now I'm devastated.
1 I thought that someone was using electricity at our expense, but I can't check.
2 I thought the counter was wrong. I read that there are problems with these meters abroad. Disturbances due to the location of the meter and elements near it. I hoped that this was the reason, but it is impossible to check it
3 What I tried to check was I turned off the fuses to see if the counter shows consumption - it shows 0 consumption
4. I turned off the fuses and left only the one responsible for the hot water tank on. If the problem was in this tank, I hoped that within an hour, with all devices turned off, I would have about 0.07 -0.08 kWh in every 30 minutes, as I have for 4 months, but I have almost nothing.
12:00pm 0.01 kWh
12:30pm 0.01 kWh
1:00pm 0 kWh
I know that it is not possible for someone to turn something on immediately after we left and for 4 months for it to consume 0.07 kWh every 30 minutes. If an hour was enough to test this water heater, it would show that it is not a water heater. On the other hand, now we have all devices under power even when they are not turned on. This should also give us the same consumption, but we have 0.01 kWh each, so this is not the reason.
I think there was something with the counter after all. There was a huge metal box with some wires there and it was impossible to remove it to get to our meter, maybe it had an impact on consumption.
To be honest, I have no idea because I don't have any new devices, only the ones I had before I left. Why don't I have the same wear and tear all the time as when I was away? If anything consumed electricity, I should now have at least this amount of consumption - and sometimes I have less. I don't assume much wear and tear during the apartment, because the apartment is on the top floor, the roof is without insulation and there are 3 external walls.
I didn't understand one thing - consumption is shown in real time, but at the same time on September 24 between 12 AM and 1.30 AM it is shown with a "24 hour delay", the time change is in October and not in September?
Do you have any ideas on how I can check where this 4-month consumption is coming from?

the thing is that I am not able to determine which device consumes electricity because everything was turned off. The plugs of all devices were disconnected and the sockets were also turned off. The only thing left energized was the electric water cylinder. - here there was a programmer connected to the electricity, which is turned on manually when hot water is needed. So I don't have to check the devices, and yet I connected the devices one by one with the water heater turned off and the consumption was lower than when we left and turned everything off. Then I turned off all the fuses and left only the cylinder with it connected (with the programmer diode on) and there was zero consumption. Therefore, I am sure that no device in the house caused the electricity consumption that must have already occurred before our departure, but since we used electricity we could not notice the additional consumption. Analyzing the daily consumption since the meter was installed, I noticed that there was a similar situation in the past, when the electricity consumption was the same when we were absent for several days. If it was due to our devices, they would not consume any electricity after completely disconnecting them. In my opinion, the problem is with the meter or someone is drawing electricity for us. It may not happen all the time, but it does happen. Why, if these are devices that produce consumption - why then, when they were not connected to electricity at all, there was consumption, but now, when they are used, there is no such consumption. Especially since it was the same consumption of 0.07-0.08 kWh per hour. The one-time night wear may have been caused by someone using our apartment during the night for 1.5 hours on September 24. I read that there may be interference due to the location of the meter, because a regular meter measures consumption linearly, while a smart meter measures consumption in impulses. Someone wrote somewhere about the voltage that may be different on the meter and in the fuse box? but I didn't understand what this was about. If the devices were connected and the consumption was too high, you can look for the source of this consumption, but how should I look for the electricity consumption when everything was turned off and we were away for almost 5 months at that time and the consumption of 0.07 is already visible in the next 30 minutes after everything is turned off? and leaving the house. So it was also added when we used electricity earlier - but this could not be detected. I don't know if the electrician will detect it? I would think it would be a very professional person with experience, but I don't have one. Even if OVO found that the meter was the cause, they would never admit it to me because they would have to refund the money even for the 4.5 months of our absence. That's why I asked for the meter to be replaced. Now I'm trying to get rid of this apartment because I can't afford to pay for unused electricity. Therefore, I want to confirm again that the wear and tear was not caused by connected devices at home, as everything was turned off. We consume a lot when we are at home due to heating, but I cannot agree to the additional costs of electricity that we did not use. Consumption when you are at home is not constant - it varies by several or several kWh, while consumption when you are away is the same - daily consumption varies by 0.02 kWh, which is not possible when different devices are used at different times each day. Here you can see that there is one reason, I see that it is not in our devices.

What a puzzle @Dorota Parker - I totally understand you wanting to rule out something off at the meter, or even someone drawing power for their own use. 

We’ve made a guide here to help offer some options and things to check:

That link’s already been suggested earlier on Tim

Dorota, you said “There was a huge metal box with some wires there and it was impossible to remove it to get to our meter, maybe it had an impact on consumption.” Can you ask your daughter to send a photo of this please ? It might help.

This question “consumption is shown in real time, but at the same time on September 24 between 12 AM and 1.30 AM it is shown with a "24 hour delay"” relates to an anomaly in the OVO usage page during summer Daylight Saving hours (BST: British Summer Time). Now we’re in GMT (Greenwich Mean Time) the consumption is shown correctly. You can rest easy about anyone using your flat during that time, it’s the chart that’s misleading for that time.

Juliamc all meters are in one place looks like big wardrobe, but our meter is up the floor. Before there was big metalic box with some cable and I do not understand why it was there. Its cover my meter. To see it I must to took this box out with somebody help to get access to our meter. The door to this wardrobe was open because the metalic box do not give a chance to close properly the doors. Now when we came the box was not there and wardrobe door was close. Anyway I will be happy to change this meter to ordinary, but OVO does not wanted to do that for us. I am disabled person and my child has big students loan and we must to pay. I do not tell anything about our big usage when she is living there because of central heating and I do not want my disabled child learn in cold room to get infection. For me is not possible to find the problem. To do the photos I need to go there to Cardiff. I cannot ask my daughter to do anything more. I know that smart meters sometimes gave the problems. Only from my investigation I found that it took extra electricity when she was living there because after we left strait away was 0.07 kWh and was not possible somebody come in to the flat when we left. Only what was in electricity hot water cylinder programmer buy it was off too- only red diode was on. When I investigate and put programmer on the same how we done when we left and off fuse I found that is not any usage. When I off from fuse programmer and put unplug all appliance buy not use there was not usage too.

100% the problem is not with any appliance which was unpluged and there is not hot water cylinder too.

If OVO took out this meter we will solve the problem

That’s true, OVO won’t refit a non-smart meter, supplies are not available. 
This diode you mention, could your daughter send a photo of that ? I don’t know what a diode is but maybe that’s using power ? Perhaps someone here could advise  ?

A diode is effectively a one-way switch of a particular kind. But that’s not enough to know what kind it is or what it’s doing.

I suspect the diode in this case is an LED

Is it possible that if it’s faulty it would draw that much electricity ?

Nope. LEDs use barely anything and if they even try to draw excessive juice, they’ll just fail and break.

If the water heater’s LED is lit, it indicates that the circuit is live and the heater is thus capable of being turned on, e.g. programmatically. That’s not the problem, I think.

The problem is that when nobody’s there, something is drawing a constant 150W. Dorota was suspicious: “Sometime I think that our lights in the building are eat our electricity.”

There is a mysterious ‘box of wires’ next to the meter. When it’s removed (and we don’t know whether that involved disconnecting anything), the meter only shows a 0-20W draw. My devious mind envisages something like an unscrupulous landlord piggybacking on Dorota’s supply for his own purposes.

@Tim_OVO @Emmanuelle_OVO In view of the disabilities involved, would it be possible to arrange a PSR engineer visit to get to the bottom of this? 

You think the Landlord is abstracting electricity @Firedog ?

If so, that definitely qualifies for a deeper look.

@Dorota Parker if you can, please show us photos of the meter, everything around it and this “box of wires”. Make sure not to touch anything and if you feel unsafe, call 105 immediately.

It’s just Dorota’s daughter in the flat now, and it sounds like the meter is not accessible to her, being high up in a cupboard, also the box of wires is no longer there. If an engineer could visit that would really help.

No. But if I were a suspicious conspiracy theorist, that is one scenario that comes to mind. It might have happened by mistake, of course; an electrical cowboy just wired the communal lighting into the nearest slot. Can you think of any other explanation?

Dorota deserves to have some concrete evidence from an expert to back any claim for compensation, and to ensure that she’s not charged for energy she’s not using in the future. 

Yeah, I definitely don’t think Dorota has tampered with the meter - the motive just isn’t there. And besides, who would even tamper with a meter to make it record more usage than was actually used? That would be self-defeating.

However, I do agree that something dodgy is going on which is beyond Dorota’s reasonable control - or beyond even their unreasonable control - and that’s where I think we’ll crack this case. Your scenario is the most logical one to me.

@Dorota Parker I've lost track of the box of wires !! I think you said it’s been removed. Has the 0.07kWh gone too?
Can you show us a day’s worth of usage now please? I appreciate that if your daughter is at the flat it’ll show normal usage too but it might be possible to detect the background use.

If the box of wires was connected to your fuse board (maybe mistakenly) then perhaps there were lights or something eating your electricity!