Unexplained half hourly usage pattern

I did find that Mum has had very high usage in the past. This is for colder Months. 
 

You should also have access to all of your mother’s past bills with OVO. Was she with another company before April 2025? What kind of meter did she have before the smart meter was installed? Has her property ever had a heating system such as storage heaters? Did it once, perhaps, have Economy 7 to control heating and hot water? Did she once have an RTS (Radio Teleswitch) meter that was removed when the smart meter was installed? Like many here, I am really trying to work out why, as you have noticed, there is no recorded usage on your graph display from midnight to 7am. This is, as I am sure you have also noticed is 7 hours. The clocks changed on March 29th this year. Could you look at a day in March before that date? Is it still midnight to 7am that shows no usage?

​@Bendog lots of questions I can’t answer I’m afraid. 
but I think you’re on the right track. Spike started shifted the 1 hour after March 29

Here is the 29th. Interestingly no

major spike in the morning.

The big thing that stand our to me there is one word in those screenshots “Estimated”.

If previous billing has been based on estimates and not actual readings - (and if the new smart meter not providing readings to DDC yet? As apappears to be the case) - then it may be that the latest usage figures are also estimated.

Similar to as ​@Firedog asked above please check the recent meter reading history, since the new smart meter was installed, does it say “Smart” or does it say “Estimated” next to them?

My apologies, but another observation from me: The SWALEC estimate of annual usage of 7325 kWh from 2021 is on the high side, but I would say perfectly within the realms of possibility.  Ofgem reckon that a high user of electricity would, typically, use 6700 kWh per year. (I do know that your mother lives alone and their estimate is based on a house with 4+ bedrooms with 4 to 5 occupants). However, the OVO estimate of 13816 kWh for a year is close to twice what SWALEC estimated and way beyond what Ofgem regard as a high domestic user. You say that nothing your mother does now is different from what she did in 2021. What I am going to suggest now will take some time to actually complete, but it may help to work out what is using such a high amount of electricity every day. Looking at the figures you have supplied for 2025-2026, the usage works out at just under 41 kWh per day. If we forget for a moment the original reason for your post (the strange recorded usage) and assume that the usage is correct, something has been using that energy. Back when energy prices last went crazy, we bought a couple of energy monitors like this to see what things in our home used the most electricity.

It was very useful in identifying the things that were more or less expensive than we expected. It may be worth looking at things like your mother’s fridge freezer, the heaters she uses, when necessary and other things that she uses a few times a day. We did this for our kettle, fridge freezers, our oven, TVs and tumble dryer. As a result, we changed our habits: we bought a water boiler that only heats enough water each time for one cup (only one of us drinks tea and coffee) to replace the kettle, we bought an air fryer (misnamed appliance as it is a small oven in reality) which means we rarely use the main electric oven and we now, as often as possible, dry things on the line in the garden and almost never use the tumble dryer. In 2022 we used 3649 kWh of electricity over the year, in 2025, we used 2837 kWh of electricity. We have gas for heating and hot water. This may help to see if your mother’s bills can be brought down even if we have not yet got to the root of the strange display of usage. 

One final thing: I have sight problems so access my OVO account, mostly, on my PC rather than on my phone. It may be worth looking at your account there to see if the display there is any different to the app.

​@Ben_OVO is there any plan that is current that would show zero usage at night between these hours. When I can guarantee there are lights on, TV on and fan heater ??

I appreciate all the input but I would like to understand if anyone knows of any scenarios that would see 0 use for those hours ??

All readings are “Smart”

Photos. 
 

Two fan heaters Mum has running 

Lights, Small TV, Fridge/Freezer and Kettle are the other devices.  She does have one of those heat on demand Shower Units as well. 
 

Photos. 
 

Mums Fuse board inside the house

Smart meter

Hey ​@rogerp64 

Thanks for sharing those photos, those are super helpful, though I definitely still have a few more questions about your mum’s set up.

I do wonder how long she runs both heaters? Though doesn’t account for the timings not matching up/missing from the AM where you say she’s up and active.

There definitely isn’t such a thing, unless there simply was no usage during that time which you’ve mentioned mum is a night owl so that sounds odd if it’s not showing usage during the expected times. It was already mentioned and shared previously but it might be worth seeing if mum can complete what’s known as a kettle test. 

• Take a reading from the meter you think is yours (take a photo of the meter clearly showing the Meter Serial Number and reading)
• Use as much electricity as possible for 15 mins eg boil your kettle three or four times, turn on the TV and all appliances and lights, use your hairdryer etc
• Check if your meter’s clocked some electricity usage (boiling a kettle once normally uses 1kwh of electricity). Take a second photo of the reading.
• If your meter hasn’t clocked any electricity use, then the usage may have been clocked on a neighboring meter

This would help make sure the meter in question is definitely the meter clocking the energy to the account.  I would also suggest reaching out to the Support Team to cross check the meter details are correct. This way they can also double check, request a meter reading to test the meter connectivity as well as any other things they can check that we can’t here at the Forum.

It’s tricky to tell but we appreciate your photos and information and hopefully we can get to the bottom of things for you and your mum.

I wonder if ​@Peter E might have any insights from your electrical expertise? 

Photos. 
 

Two fan heaters Mum has running 

Lights, Small TV, Fridge/Freezer and Kettle are the other devices.  She does have one of those heat on demand Shower Units as well. 
 

 

I hope that these heaters have thermostat controls. Many such heaters are capable of using 3kW of electricity every hour they are in use. (This is just an observation as I know that usage and cost are not your primary concerns). I remember living in a couple of properties where this kind of heater was my source of heating and how comforting the instant heat was but how disappointing it was that I quickly became cold once they were switched off.

thank you ​@Abby_OVO , 

The MSN on the Meter matches the MSN in the Portal.

I’d have to arrange for someone to do the kettle test.. Mum would not be able to do that and I’m very distant from her..  so photos, etc are coming from carers that drop in.

As you say there zero usage is still the big unexplained element..  the Fridge/Freezer is on 24*7, TV, heaters and lights are on and iPad is charging always after midnight until at least 4 or 5:00am.

​@Bendog - I think they do have thermostats, but Mum has them cranked to the max… so doubt they ever cut out….  However, she is never downstairs using the heaters in the early morning.. and most certainly wouldn’t be turning them on at 07:00 on the dot…

(I’m secretly happy that there is no clear and obvious answer, but I can bet that when the answer is found it’ll be instantly clear and obvious !!)

​@Abby_OVO and others. I have been following this but I've not been able to come to any clear conclusion mainly due to the lack of information so I'm going to try a different tack to see if the usage is at least explicable.

I have an elderly mum who is now 96 and she has the house very hot. Taking my house as maybe being something to your mum’s, 41kWh a day will maintain a temperature differential between the outside and inside of about 9C. The current average temperature at the moment on the south coast (I don't know where you are but it is probably cooler if you are significantly further north) is about 12C giving me an internal temperature of 21C. That is not an unusual temperature for someone who is elderly and perhaps not very mobile.

41kW a day is a steady 1.7kW. I noticed that it is just possible to see that the fan heater is set to 1kW but I don't know what the thermostat is set to. After all that I can't say that 41kWh a day is what you are using but it seems possible, given the circumstances, that it us possible for that to happen.

I'm going to go back and re-read everything I've said and see if what I've said is still feasible. If you've any comments please let me know. This is a complete punt in the dark 

I think ​@Nukecad is right about estimated readings and I've been fooled by by the graph before. My one showing usage when we had a long power cut.

Peter

A note. It's only a 2kW heater. 3kW heaters were banned from being sold some time ago as they were causing sockets to burn out. Although they are called 13A sockets and the plug has a nominally rated 13A fuse (they will take a lot more) the plug/socket is only rated for 10A continuous current.

13,800 kWh a year is an average of 37.8kWh a day just to refine the figure a bit although I’ve now thought that would be a year average figure. In my house with a room temperature of 19C my heating season energy is about 10,000kWh with my non heating season energy to be added to that.

Peter 

I’m getting a little tired of Ovo telling me that they are charging my Mother for her usage..

This is a message from Ovo..  “Your mom uses more electricity hence that could be a reason behind the high usage as we are not over charging her. Our readings are accurate.”

My response was… “My 88 year old Mother lives alone... and you have her down as using 13000 KWH+ per annum....and I am still waiting for an answer to the question of ZERO usage from exactly midnight to exactly 07:00am each day.. zero, nothing, nil...how can that be accurate ?

Ovo response to that summary page image..  “Your mom is on a single rate”

My response “and is that the answer as to why there is ZERO usage between midnight and 7:00am each day... ?? and why a single 88 year old is being charged over 3500 pounds per year”

thanks for chipping in ​@Peter E ….  my Mum’s house is freezing !!  the electric water heater has been switched off for years.. she has no electric central heating.. I guess I keep coming back to the images that show ZERO usage from Midnight to 7:00am each day.

The comment that ​@Nukecad made could be valid as the graph can display erroneous values without real data to base it on. It’s the smart readings page that is important. They will show you if smart readings are being taken and what the values actually were. As I no longer have an OVO account I can't help you in locating the smart readings data page. If the  readings are estimated then the whole graph is a fiction and there is no knowing what that is based on. I've had that problem myself.

Peter

​@rogerp64 Thanks for the photos and the other details. 

I agree with ​@Peter E. It would be really interesting to see the meter readings from before April 2025 and - ideally - to date. You remarked earlier that All readings are “Smart”, but we don’t know whether that applies to the period before the new meter was installed in ‘early March 2026’. 

If for some reason half-hourly usage data aren’t being retrieved from the meter, the website will simulate the missing data using (to me!) completely impenetrable logic. So even though meter readings are getting through, the graphs on the Usage pages may be complete fabrications. 
  

  
Your remarks about the replies you’ve had from Support make distressing reading. My own experience of the special staff who respond when someone on the Priority Services Register contacts Support has been limited, but in every case, the respondent has been courteous, knowledgeable and helpful. I assumed - since you have access to mother’s account - that OVO know you’re acting for a vulnerable relative, so I wonder why you’ve been getting apparently unhelpful responses.  

On her account’s Profile page, you should see details like name, address, email address and phone number. I’m not certain how your details would appear on this page, but I think they ought to be there. Perhaps ​@Ben_OVO could tell us. What is vital, though, is that any contact with support starts from a recorded email address or phone number - that’s how enquiries get routed to the right people. I prefer to use the chat options, so that I get a written record of the conversation.

And incidentally, on the same profile page, you should see an option called Set how often meter readings send. You might want to check the settings there. 

To double check that the smart meter is sending readings, when you log into the app in the bottom menu bar is an option marked “Usage”. Tap through to that, and under the graph that pops up is a box marked “Meter Readings”. Tap on that, and on the next screen you’ll see your meter details for electricity and/or gas (as applicable), and within each box you can tap on “View Reading History” to see all the readings and it will tell you for each reading if it was a Smart reading, or if it was estimated.

​@woodstok2000 Smart reader installed 11th March this year. Every day shows ‘Smart’

Thanks ​@Firedog Smart reader wa installed March 11 this year. All readings prior would have been manual. 
 

I will see what I can find on previous usage for Mum. I know that I inadvertently cancelled her plan, when I noticed a huge jump in the monthly costs. I received a £3000 refund, I contacted Ovo to say that I hadn’t expected a refund and I have since repaid the money. 
 

Now I am wondering if the refund was based on overpayment in 2022, 2023, etc. I will get my forensic kit on and start to dig. 
 

** the zero usage between Midnight and 7:00 still remains a mystery to us all. Ovo telling me that the meter readings are ‘accurate’ is the major gripe I have. How can they be accurate if there is zero use for 7 hours a day?for those hours every night suggesting that my Mum has flicked the main circuit breaker exactly at midnight and waits until 7:00am each morning to turn it back on? (1. The circuit board is out of reach, even for me, 2. Mum hasn’t been awake at 07:00 for years)!!!

When we had our smart meter installed, the daily readings to Ovo were fine, but our usage graphs were all over the place - it turned out we had the meter set to send daily readings, and so the app was essentially ‘inventing’ our hourly usage to match expected patterns.  Could that be the case here?

In the app, top right is a little black circle with a person in it, if you tap that it takes you to your account details.  There’s a section near the bottom marked ‘settings’, and one of the options there is ‘How often meter reads send’.  Tap on that and check what it is currently.  If it’s set to daily or monthly, change it so that it is set to ‘every half hour’ for both billing and settlement data.

Based on your mums current reads of 30kWh per day (in March, so relatively mild), 13,000 kWh per year does not seem unreasonable.