I think my meter is clocking too fast - How can I test if my high usage is due to a faulty meter?

I think my meter is clocking too fast - How can I test if my high usage is due to a faulty meter?
Userlevel 7

​​​​​​Your guide to checking the accuracy of your meter: How to carry out a Creep Test, a circuit check and book a Meter Accuracy Test (MAT)


Have you noticed a sudden leap in the amount of energy your meter’s clocking? Are you worried that it might not reflect what you’re actually using? We’ve made this guide to help outline all of your options so you can be confident that everything’s working as it should, and you’re only being charged for what you’re actually using. 


My bill is higher than usual

First things first, I would say it’s always worth checking that the higher than usual billing is based on actual readings rather than estimated readings.


You can view the latest statement on the ‘Billing history’ page of your online account or OVO app (download for Android or iOS):


Exact appearance may vary


‘Download this bill’ or ‘View details’ to see if the reading is estimated (hint: it will say estimated next to the reading if this is the case). By checking the reading on the meter and submitting it on the ‘meter readings’ page you can correct any over-estimated readings.


It’s also worth checking that you’ve been charged the correct unit rates and standing charges. These might have changed recently if your fixed plan came to an end or your variable rates increased - we always send you an email to let you know but you can find out the prices on your current plan (and whether you could switch to a cheaper plan) on the ‘Plan’ page.


The details on the bill are correct but I’m sure I didn’t use this much


Higher than normal usage is normally due to changes in your usage patterns (which aren’t always easily spotted). Can you think of any reason why you might have used more than you expected recently? Common factors might be a colder than usual season, buying a new appliance or a change in circumstances (ie. working from home). It’s best to take these factors into consideration when trying to explain a sudden increase in usage. 


If you haven’t already got a smart meter then I’d say this is the perfect time to get one installed! Get your free smart meter installation booked here.  Not only are new meters more accurate, they also allow you to monitor your usage over a half-hourly, daily or monthly view with some handy usage graphs on the usage page of your online account or OVO app. Using these you can pinpoint when exactly your usage peaks - this can really help us get to the bottom of what might be causing the increase - notice a spike at exactly the time your immersion heater is set to come on? - this might explain things! 


I’ve got high gas usage, should I check my boiler?


The most likely cause of an unexplained increase in how much gas you’re using (and it’s always worth checking your usage against the same period last year, as it’s very seasonal!) could be down to a faulty gas boiler. A boiler which is older or potentially faulty can use more gas to achieve the same heat output. If you’ve got the OVO Homeplan, an annual boiler check is included to make sure your boiler health is checked regularly. If you don’t have this, it might be worth considering contacting a gas safe engineer to make sure your boiler’s in tiptop condition.


What’s the best way to locate an energy guzzling appliance?


Worried that your electricity usage seems high? By checking the usage of each circuit you might be able to find out the particular appliance which is the culprit. The meter will need to have decimals showing in the reading for this test to be useful:

  1. Leave the main breaker in.
  2. Turn off all individual circuits (on the fuse board, for example).
  3. The electricity meter should stop clocking usage. If not, there could be a short in the fuse/breaker panel box or an appliance connected without fuse/breaker protection. An electrician will be needed to investigate this.
  4. Turn on one individual circuit.
  5. Watch to see if the electric meter starts to clock usage.
  6. Turn off that individual circuit and turn on another one. Again, watch to see if the electric meter is clocking.
  7. Repeat step 6 until all individual circuits have been checked.

You’re looking for a circuit that causes the meter to clock a lot of usage, compared to the other circuits. There could be a problem with an appliance or a connection on that circuit. We’d recommend contacting an electrician to check the appliances on this circuit - particularly if there are any old or potentially faulty appliances plugged in.  Find out the average usage for each appliances on this great guide and some great energy saving advice on the Centre for Sustainable Energy.

How do I perform a Creep Test on my electricity meter?

If you’ve been unable to get to the bottom of an increase in our usage by locating a greedy appliance, the next step would be to carry out an initial check on the accuracy of the meter with a ‘Creep Test’. To carry this out: turn off the power to your fuse box and check if the meter continues to clock. If the meter clocks (more than 1 - 2 units which could be down to residual power in the wires)  then it's either faulty, or clocking someone else’s usage.


If your meter is in a communal meter cupboard, sometimes the meter details can get mixed up. Firstly it’s worth checking the meter serial number on the meter matches the serial number registered on your account. You can see this on the ‘Meter readings’ page of your online account:


Exact appearance may vary


Even if the meter serial number matches, there is a chance that your meter details have been mis-registered. If you suspect this might be the case, contact our Support Team who can arrange a ‘fuse finder’ to confirm which meter is clocking your usage.


How do I book a Meter Accuracy Test (MAT)?

Completed a ‘Creep Test’ and seen a possible fault? The next step would be to book in a ‘Meter Accuracy Test’ (MAT), by contacting our Support Team.


As the MAT involves an engineer visit, there’s an upfront charge to get this arranged, which will be reimbursed if a meter fault is confirmed. A meter is considered faulty if it’s clocking at least 2.5% faster or 3.5% slower than it should. It’s worth considering all other possible causes for a usage spike before booking in this appointment as we can’t guarantee the results, and the cost of this test won’t be refunded if the meter is clocking within the above tolerances. If the meter is found to be faulty, we’ll replace it and re-calculate all the statements issued since the meter fault began. These statements will be based on your average usage, or your usage with the new meter. 


Hope this helps get to the bottom of your meter accuracy concerns. Have you noticed a recent spike in your usage and need help working out why? Comment below as we love to help you investigate! :relaxed:


158 replies

Userlevel 7
Badge +3

I wish I could explain this one, but I’m stumped unfortunately. I’ll see if our secret weapon @Transparent can figure this puzzle out.

This forum is volunteer led and pretty much everyone except Tim and Jess are volunteers. It wouldn’t be fair to say that you should implicitly trust us by default as that would get you into some really tight spots if you’re not careful. But I like to think that we can try to help figure these issues out without causing too much hassle or cost.

Userlevel 3

Thanks @Blastoise186 any useful suggestions at all please  @Transparent ??


All suggestions welcome at this point.. I think that MAT test may be the answer but I’m concerned for they suggest that 80% of tests prove no fault. Obviously that means 1:5 are faulty so...

Userlevel 3

last read for today suggests 11.3Kwh since 08:16… includes a correction for earlier when I missed a read:smirk::thinking:

Userlevel 3

overnight consumption 4.1Kwh, does that sound normal?

Userlevel 7

Yeah it can be a real puzzler - and unfortunately we can’t say for certain what might be causing the fluctuations in usage you’ve seen, @fatbloke88 .


The best advice would be to carry out as many checks as possible before determining that a Meter Accuracy Test is required. We can’t guarantee the results of the test until it’s been completed so it’s always best to rule out other possible causes first.

Have you carried out a circuit check yet? - This could really help isolate the usage down to a particular circuit or appliance which we’d then encourage you to get checked by an electrician. Let us know if this does explain things, we’d love to hear when you get to the bottom of things! :thumbsup:

Userlevel 7
Badge +3

That does sound more realistic.

To give you some more context that might help you though, I can offer some extra advice. My smart meter is called Raichu, which is the nickname I gave my S2 Aclara SGM1411-B. It’s a long story that Tim might explain. :)

Anyway, as part of the feature set, Raichu is capable of running a whole bunch of self-diagnostics on a constant basis and performs self-calibration checks periodically to verify that the calibration is still in line with that which the Aclara SGM1400 Series has been approved for. It will also attempt to self-recover if a problem is detected and it’s able to do so by itself - and will also alert OVO if this happens.

In effect, the self-calibration is a bit like a “Mini Meter Accuracy Test” and it’s a common feature in most Smart Meters. It’s not a perfect thing as it can sometimes go wrong, but it’s a lot better than traditional ,meters where you had absolutely no self-diagnostic, no self-calibration and no self-recovery at all.

Userlevel 7
Badge +5

Hi @fatbloke88 - I’ve read through all of the discussions above, and I think we don’t have enough information to resolve this issue.

The nature of the excessive-usage is sporadic. We can’t detect any pattern from what you’ve observed.

I think the sequence of testing each ‘circuit’ individually, as @Jess_OVO suggested above is the best advice thus far.


Unlike you, I have a grid-connected device (a PowerVault Storage Battery) which produces usage graphs based on intervals of about 1 minute. This enables me to decipher the normal pattern of usage which is typical of my house:

The freezer and (two) fridges form part of the ‘base-load’ which hovers around 800w.

But the high-power devices such as kettle, microwave and power-tools clearly stand out above this line.


This is quite different from the level of detail which can be obtained from a Smart Meter, which collates half-hour averages, or an IHD which displays 3 or 4 snapshots per minute.


To gain an overview of what’s happening in a house such as yours, we need a mains ‘meter’ which acts as a data-logger. These monitors exist and can be fitted into any or all of the circuits fed by a Consumer Unit.

Here’s such a Smart Monitor which I’ve had fitted into a new circuit that charges my EV


In this case I still have to push the button and manually read the display. But it presents me with a wide array of data: Voltage, Current, Active Power, reactive power, power factor, frequency, Total Energy kWh etc.


There are also similar meters which use a MODBUS data-network. This is an ‘industry standard’ 2-wire network which allows multiple meters to be connected to a Modbus TCP adaptor, and thence to a computer or cloud-based storage.

Such a Modbus meter can cost between £25-50 (plus installation) and can monitor over 40 electrical parameters at pre-configured intervals as small as one second.

The problem is that they can create vast volumes of data which then needs storing and analysing!


Over the past six months of dialogue with OVO I’ve realised that they know very little about the normal patterns of energy usage in our homes!

This seems odd when they are increasingly giving us advice on how to save energy.

It’s even more of a knowledge-deficit when you consider that their Kaluza division is developing the Flex Platform to remotely control high-power devices in the home, and a new Billing System to provide flexible Time Of Use tariffs.

Those algorithms really need to take into account the ‘normal’ pattern of usage. And that means OVO must somehow create a knowledge-base of what electricity usage looks like now - a reference-point from which later changes can be detected.


In your case such a knowledge base would enable us to detect the abnormal usage which now seems to be afflicting your system.

Indeed, in future the Billing System could in theory notice the anomalous pattern change and send an alert to you and an OVO technical support engineer to tell you that something is going wrong!

To me, as a fellow consumer, that’s when I start believing that the Smart Meter has progressed to the first rung on the ladder of ‘being smart’!


Whilst I may not immediately be able to diagnose what problem is affecting your site, there are two ‘solutions’ which OVO needs to explore. I’m putting them here so that the Forum Moderators can ask the relevant in-house staff to read this post!


1: To the Smart Meter Team: Is it possible to write a piece of diagnostic code to be downloaded into a customer’s Smart Meter which could log current-peaks over a period of 30-mins and deliver these back to OVO ?

Thus, instead of requiring a MAT test, the first stage would be to ask the meter itself to check actual usage every 30-secs, utilising one of the spare tariff-slots which currently do nothing! Those 60 readings can then be compared to both the daily costs which you are being charged, and a knowledge-base of ‘normal usage’.

It’s not ideal because it uses the same meter, which may be faulty of course. But it’s a huge step in the right direction.


2: To the Smart Home Team: amongst the 500-odd trial sites which you’re currently running, find some customers who would be prepared to have some Modbus meters fitted.

This would allow you to build the knowledge-base which will be required to generate smart algorithms in the Billing System and Flex so that you can start to deliver the tools us customers require to save energy, provide fault-analysis and help us combat Climate Change.


Over to you @Jess_OVO and @Tim_OVO !

Userlevel 3

Thank you @Transparent the data logger add on might be an idea for the future and knowing what “normal” looks like would also be useful. From the chart you’ve provided am i right in thinking that is the output from the “PowerVault Storage Battery “ and that the image of the smart meter for your eV is separate to the standard “smart mete” as its sitting adjacent to your main distribution board?

Userlevel 7
Badge +5

Yes to both of those @fatbloke88.

I’m a participant on the current PowerVault Battery Trial which OVO are running. But the more I became aware of what they want to deliver, I realised that they  don’t have enough incoming data to understand the effect of operating that battery.

The fact that I’ve just bought an EV makes matters worse. Whilst Flex will try to manage the PowerVault unit, it will be operating blind to the influence of my decisions on charging.

And that’s why I’ve started looking further into how the required algorithms can be created… without requiring every customer to use Modbus Metering of course!

It’s a bonus that the same techniques would also lend themselves to resolving incorrect meter readings for sites like yours. But that makes it all the more important for OVO to start collecting this data of course.

Userlevel 3

well I’ve done the test as @Jess_OVO sugested and no discernable difference when any switch was powered on, the meter halted with all power off as expected and barely registered any change as individual switches were thrown.

I realise I didn’t do each switch individually in isolation to the others, is that something I should try again?

I’m not sure that this type of test will demonstrate any real issue because I dont believe I have a faulty (high consumption item in the house). Anyone any thoughts on this before I turn the missus’s shower off again?

The consumption since the massive 2580kwh jump 14-20 July has been averaging 15Kwh p/d so I’m not convinced about a faulty meter consistently mis-reporting. I’m left wondering if anyone else going through this upgrade saw a similar spike in usage over the upgrade period?

There have been some strange spikes referrred to above again does anyone else have anything similar to report?



Userlevel 7
Badge +5

The information we don’t have @fatbloke88 is what configuration gets put into your SMETS1 meter when it’s upgraded to SMETS2 software.

If the anomalies were solely related to price, then we might reasonably suppose that the memory locations where your tariff data has been stored have defaulted to an arbitrary default value.

Once your site gets passed across to OVO by the Data Communications Company (DCC), the correct tariff would get sent across by their Billing System.

In your case there seems to have arisen a sudden jump in the consumption itself (measured in kWh). We could conjecture that there might be a memory location where the SMETS firmware holds a ‘calibration factor’. But I’ve not heard of such a system before and don’t know if Secure’s meters operate like this.

Whilst I remain intrigued from a technical viewpoint, I don’t believe there’s any need to be concerned that you will end up paying for such an error.

At this stage you haven’t even received a bill which covers the days on which the suspicious readings have occurred.

Nor can the Billing System start sending you invoices or warnings to ‘increase your Direct Debit’ because it can take weeks for a meter to be tested on the upgraded software and then passed across to OVO by DCC.

So panic not!

If you want to cover all eventualities you could email hello@ovoenergy.com and state something like:

Further to our telephone conversation of Nth July, I appreciate that my early Smart Meter is in the process of being migrated to the National Network.

The meter continues to provide consumption readings which are significantly greater that have occurred during the previous months on my contract with you. I accept that this process includes a number of technical steps and that testing may yet take some time.

I am reassured by your assertion that my account will be credited for the erroneous readings during this time.

That basically put in writing a date/time-stamped copy of what you were told on the phone. If any of it is incorrect, then OVO has the opportunity to refute that.

In any case, the email stays ‘on your file’.

Under those circumstances, even if you do get emails asking you for extra payments, you can safely ignore them. There is no possibility of you being threatened with legal action because the High Court (Small claims division) would be unlikely to let it proceed to a hearing. As soon as you produce a copy of the email, the case would have to be withdrawn.

Userlevel 6


I am no expert… I really am not... 

I would just add one of our fridge freezers has struggled during the hot spell and i am sure used a bit more electricity. It is a built in model in the kitchen and in hindsight i am sure not in a great place quite close to vertical/horizontal plumbing pipes and quite close to double oven although not directly next to it. Lesson learned. It was an A rated appliance when we bought it, but given there were A+++ devices at the time the ratings were pretty meaningless in hindsight i see.

I see ratings have recently changed. Our electricity usage hasn't changed much from what i can see over the last few weeks but always difficult to know. 

Anyway. I have a couple of wemo insight smart plugs, had them for many years as there wasn't many smart plugs until more recently. It provides power consumed info as well as being a regular smart plug. Am sure there are much better makes and models now, can't say i would recommend the wemo ones now. For example something like this, 10.99 on amazon as I type. 


I only really use our old smart plugs for security to turn lights on when we are away these days. 

If you think it might be something like a fridge freezer issue perhaps getting a smart plug that measures kw usage might help check? You can always make use of the plug elsewhere later. They may not be super accurate but i don't think that matters. You would need to check the smart plug would work with something like a fridge freezer. You may find someone with a smartplug that measures energy consumption you could borrow? 




I’ve been with OVO for awhile but ever since I had smart meter fitted my bills have been more than it should be 


I live in a one bedroom warden controlled bungalow , I have no cooker or washing machine as I live 2 doors from my sister and I go there for meals and to do washing , I’m out of bungalow from 8am till 6pm , don’t have a swimming pool or a hot tub but my bills are >  £70 / month but my sister who lives in an exact replica of bungalow and does cooking and has washing machine and stays in all the time , her bills are about £45/ month . I have phoned a few times to say my smart meter is faulty but they just fob me off . I’m now sick of the bills 


so I tried to join another supplier today but he said they couldn’t transfer me because “ my meter is locked ? And I need to ask OVO to unlock it “ how do I do this as I just want to leave 



Userlevel 7
Badge +3

Hi there @Atherz .

I’m really sorry to hear about that. I can try to offer some advice to help sort the original issue out, but I will also respect your request in the meantime.

I’ve never actually heard of a meter being locked as such, but I’ve asked @Jess_OVO if she knows anything.

If you’d like me to try to help solve the other issue instead of leaving OVO, please feel free to let me know. I can’t access your account, but I can offer advice. If you’d still prefer to leave anyway, I will understand.


I am paying £20 /more than my sister who uses lots more energy than I am 

Userlevel 7
Badge +3

I understand. If you’re able to access MyOVO, it might be possible to reduce your payments a bit to match your actual usage. That would be the fastest solution to this issue.

Don’t forget that regardless of your payments, you’ll only ever be charged for what you actually use and the rest stays on your account for the future bills. It sounds to me as if the Estimated Annual Consumption (EAC) figures might be a bit out in your case, but this too can be fixed - especially once your smart meter starts talking to OVO. The Support Team can change this for you and they can also adjust your Direct Debits and issue a refund if needed.

Next time you contact them, please let the agent know you’ve been getting help from Blastoise186 on the forum and direct them to this thread. It will help a lot and I can assure you of that. Tim and Jess are both OVO Employees who monitor this forum every weekday, so they’ll be able to offer advice as well if needed.

I hope this helps. If you're unable to resolve this issue, I recommend using the Complaints Process which has a very high success rate and is usually pretty quick at getting a response. There’s a strong chance someone from the Complaints Team will respond within five working days if you go down this route. They’ll get you sorted out.

Userlevel 7

Don’t forget that regardless of your payments, you’ll only ever be charged for what you actually use and the rest stays on your account for the future bills.



Good shout this ^^^


@Atherz thanks for posting, it’s an interesting one this with such a close comparison possible between properties of a similar type. As Blastoise186 mentioned, we’ll be happy to help you drill down into these costs, and also with any advice on switching. Your meter being ‘locked’ has me scratching my head, but I’ll get to that. 


Would you be able to read the main article of this topic that Jess posted - I’ve moved your topic thread and combined it with the one Jess made as it’s very relevant here? She’s just recently posted it, and this outlines various things you can do at home to work out why you’ve got higher then expected costs. 


Some info from you would help us to help you: 


Can you also confirm via your online account if your Direct Debit is > £70, or if that is the rough amount of your charges? 


Can you let us know what smart meter you have, or even better: send us a picture? Do you know if this smart meter is communicating with OVO remotely? You’ll have meter readings and usage info in your online account if you do have communicating smart meters.


We’re on hand to help as best we can. I’d be very surprised if there was a reason your smart meters meant you couldn’t switch. That wouldn’t be OK, switching should always be possible, otherwise it’s just not fair. So I’m hoping with a bit more info from you, we can work out your options. 




Userlevel 3

Interesting update:

according to the consumption chart on my account the consumption values seem to have dropped depite them still not getting meter readings. They were suggesting readings of around 30kwh pd but now look much better.


Q how can this be without OVO receiving a meter reading?

Q why are the last 3 days back up at 30?

My readings suggest less than 20kwh pd



My readings all backed up with photographic evidence; The red values are total consumption since SUPER HIGH READING and the green are the differences between reads. Note the times vary wildly so read dates times to get a full comparison.


Userlevel 7
Badge +3

Hmm... looks like estimates to me, but I'll take a deeper look at this in the morning. 

Userlevel 7

Hi @fatbloke88 yes as Blastoise mentioned, we do populate that online usage graph with estimates if your smart meters fail to send us that day’s consumption. From your earlier post you mentioned that enrollment and adoption to the DCC ‘S1+’ is preventing communication with your smart meters?


If that’s the reason, it’s odd to see those 3 days of higher usage on the 27th, 28th, 29th. But from what I can make out of your spreadsheet screenshot, the usage indicated in the actual readings seem to match this. Are we sure these meters aren’t sending us your readings? 


Userlevel 3

UPDATE; since i’ve been away these are the readings from my meter. The red values are total since 20/07 when that spurious high value was displayed. the green values are the differences between readings.

Still struggling to understand how and why that anamolous value appeared in the readings. My ovo is still showeing 30kwh usage which I understand is an estimate and will be corrected, the question is when and what happens to the registered consumption since the last official reading was sent?

Extra note: I had forgotten to advise this earlier; when my billing year was up, OVO advised that we had registered well in excess of our payments and I needed to make an immediate payment of nearly £500 to bring it up to date and increase the DD to £260pm!! - I thought about this on holiday, could my meter have “jumped” previously because NOTHING of substance has changed in the last 15 months regarding our energy usage… @Blastoise186@Transparent@Jess_OVO ???


My gas (meter according to “MYOVO”  appears to be sending readings but not my electric meter, the red lights on it appear to flash in different combinations at different times, despite fairly normal usage in the property - is this normal?


Userlevel 3

let me add some further info to that last post: GAS usage on 04/08 is “-68kwh” and on on 7-8/08 appx 13kwh

how can we consume a negative value and were those other 2 days particularly cold?




Userlevel 7
Badge +1

Ah, so I’m not the only one sometimes getting negative gas usage (for me, only ever on days when the meter reading is estimated). I’ve had this happen a couple of times over the last fortnight, and wonder how things will look on my next monthly statement. The statement itself only gives meter readings (m^3) at the start and end of the  billing month, but to calculate how many kWh to charge for, Ovo need to know day by day usage through the month. Even Ovo must realise that they can’t use negative values there.

Userlevel 7


I thought about this on holiday, could my meter have “jumped” previously because NOTHING of substance has changed in the last 15 months regarding our energy usage… ​​​



Interesting theory, @fatbloke88 - and a pretty tricky one to answer here for certain. Obviously a meter should be clocking your usage accurately and shouldn’t ‘jump’ readings unless there has been a sudden increase in usage - if this was the case then it would be considered faulty.


Just re-reading your original posts and realised we never confirmed exactly where you noticed the jump in readings? Was it by taking a reading manually from the meter itself? Or did you see these readings on your online account?  if so was that on the ‘usage’ pages or the ‘Billing’ pages?


Reason I ask is that often a ‘jump’ in readings is explained by the fact that we had previously been billing to an estimated reading (for example if your smart meter wasn’t yet communicating) - when we do then get an actual reading this may be a lot higher than the previous estimated reading. This ‘jump’ in readings would account for the fact that we’d previously underestimated the usage.


Obviously not sure if this would explain things in your case and it certainly doesn’t clear up the negative consumption values you’ve both seen on your gas usage graphs. I’ve taken that one away to the team, but as @Simon1D suggests this could indicate that there was a drop in the communication of your gas smart meter on that day.


Not sure if your meter has fully completed it’s upgrade journey yet, @fatbloke88,  if the intermittent signal issues persist once the upgrade is complete,  we’d recommend carrying out a smart meter health check (which does involve taking a look at the flashing lights) and forwarding the results to our Support Team, who can advise on the next steps to getting things sorted.


Hope this helps - let us know how you go :slight_smile:

Userlevel 7
Badge +5

I think this comes back to something we asked the software developers to address over a year ago.

There needs to be an ‘indicator’ such as a colour-change on the usage histogram for

  • an estimated reading
  • an automated correction (such as a Smart Meter communication being restored)
  • a manual correction

It is inevitable that such entries will continue to be required within the billing history, and there is no good reason to expect that customers should contact OVO to ask why!