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Are you losing money due to faulty electricity meter clocks?

Clock with light

They say time is money. But would you be surprised to hear that simply checking the clock on your electricity meter could save you hundreds of pounds a year? Clocks showing the wrong time are going unnoticed…

That’s the experience of a number of Which? members who have told us about problems with time-of-use tariffs, such as Economy 7 or Economy 10.

These types of tariff offer electricity at a cheaper rate during some hours and a higher one the rest of the time.

So, if your meter clock is wrong, you may find you’ve been charged over-the-odds for what you thought was cheaper electricity.

That’s what happened to Which? member Gary Day, who told us he found his own and his neighbours’ meter clocks were up to three hours out.

Thousands in over-payments

GaryRetired engineer Gary only spotted the problem when he went away for a few months, leaving just his heating on during the low-rate hours. When he returned he was shocked to discover a bill showing he had used most of his electricity at the higher rate.

Gary then found his and his neighbours’ clocks were all telling the wrong time and has told us how they won back about £2,300 in over-payments from supplier Swalec. He told us:

‘I have only checked four meters and every single one of them was wrong. I am horrified that there are probably hundreds of others that have these clock errors and don’t realise it.’

Checking your clock

Swalec said staff don’t have to check the clocks when they read meters – but added if they happen to notice any problems they must report them.

Unless the customer owns the meter, it is the supplier’s responsibility to ensure meter clocks are correct. However, current rules don’t require suppliers to check the clocks.

They do say suppliers must take ‘reasonable steps’ to ensure the accuracy of the amount and time the electricity was supplied – but this isn’t exactly the same thing.

If you suspect your electricity meter is faulty, the supplier must investigate. But this means the emphasis is on you to check.

And that’s not always simple. Peak and off-peak times vary between tariffs, regions and seasons. Add the fact that the clock can be hard to find on many meters and it can become a pretty tricky task.

Do you think it’s fair that suppliers don’t have to check the accuracy of clocks? Have you found that your own clock is inaccurate?


Radio-controlled clocks will promptly correct errors in the event of power failure have been available for years.

It would be necessary to make sure that meters are capable of picking up a reliable radio signal inside a cupboard or under the stairs, so the meter might require a small aerial.

As some of you will know, I am on a E7 meter myself and I do check the clock every Monday when I take my meter readings. It is currently 15mins out. But when the clocks change my meter doesn’t.

So on my iphone I have two clocks, one for normal time and one for my meter. I know this sounds totally stupid. But with how little energy I use I like to make sure I am using the bulk of it between 12.02am – 7.00am

I pointed out to my supplier some years ago that my meter clock was several hours slow and was told that the time shown on the meter was irrelevant as the radio signal determined the switchover from daytime to nighttime rate and was thus always correct. Have I been misinformed and thus overcharged for years? We always run our washing machine and dishwasher overnight!


I was told by the SSE manager that the meter clock is what the bills go on. This is why I added a 2nd clock to my phone.

But like i say, that is just what SSE told me, not sure who you are with. Your best bet is to tweet/phone your energy company and ask them.

A. P. McCourt says:
3 March 2014

My electricity meter did not change fro BST to GMT in August 2112. I contacted my supplier British Gas and was told that meters do not change when GMT changes to BST and vise versa but the meter operator allows a margin of 1 hour to accommodate these changes. Does this sound reasonable.? The person I spoke to said that it is impossible to change the meter by remote control !

With the roll-out of Smart Meters and the potential for having multiple time-of-use bands for any user the question of accuracy becomes even more of an issue.
I can see that checking and resetting the meter clock remotely and the possibility of hacking the time clock could be a big security issue .

Georgie says:
19 February 2014

EON came to read my parents electricity meter and noticed economy 7 meter clock was wrong. They arranged to come and change the meter and then charged my parents around £40 for money they think they were owed due to wrong time. I don’t even know where we stand on this. They should have checked meter regularly!!!

Finlay Coupar says:
20 February 2014

My meter clock is registering 11 a.m. and the time is 12.30 lunchtime so out by 1.5 hrs.

Steve Harrington says:
20 February 2014

My mother lives in a block of 3yr old retirement flats. The time on the economy 7 meter has always been wrong (about 75 minutes out). When I queried this with e-on they said this was within the industry standard of +/- 2 hours. When I questioned whether they would be charging the wrong amount when the storage heaters were drawing power, I was told they would only switch in and out when correctly activated by a signal. Bearing in mind that the clock is not being automatically corrected, and you can’t get a mobile phone signal unless you stand at a window, I doubt they are being switched at the right time. I’d be interested to hear what e-on have to say

If the storage heaters are wired into the off peak feed then surely they can only ever work during that period? They normally have a dedicated circuit. As long as this is the case I would suggest there is not a problem. The problem comes when you switch on anything at the plug thinking you are on cheap rate when you are not.

As long as you know when your ‘actual’ cheap rate is, use it to your advantage. Because the time clock is wrong I get economy 7 night rate from 1.40am till 8.40am (real time) in winter and once we are on summer time from 2.40am till 9.40am.

Why would I want my clock time corrected! Cheap rate is still going when I get up in the morning and available for use at a a sensible time. I set the washing machine to end when I am up and that is still cheap rate.

It is easy to tell from my modern electronic meter as to whether I am on day rate or night rate and I get an audible ‘clunk’ from the old clock when it switches over. As long as the time clock is running slow make the most of it, and as you say it is the suppliers responsibility to ensure the clock is correct, so their problem not mine and I am saving money.

I am surprised people do not check their time lock as a matter of routine so that you can make maximum use of the night rate

Keith Georgiou says:
11 March 2014

At last someone who is talkin sense. The further “out” the meter is then make it work for you – just check when it switches over and use the “off-peak power” for ironing/washing/showering a to save you money.

This Which article is a non story. If Which had any sense they would be telling readers to check and take advantage of any error.

Jeannette Delhomme says:
21 February 2014

I have taken another look at my recently installed new meter. I cannot find anything which resembles a clock. What am I supposed to be looking for and where is it?

I guess there are a lot of permutations, I still have the old time clock dating I think from 1984, a large ticking affair. The equally old meter was replaced years ago by a neat little white box.

The time clock triggers which set of readings on the meter are active

I can but assume that somewhere between where the supply comes into the property and the meter there will be a time clock OR the switch is done via a radio link. somewhere there must be a device which triggers the switch between peak and off peak.

Another way to check what rate you are on is to look at the meter. If it is like mine it only displays one reading at a time, the two readings cycle round over 30 seconds or so Reading 1 which is day rate is displayed, then Reading 2 which is night rate. Whichever one is active has the number flash (only the number 1 not the whole reading) During off peak rate it is the number 2 which flashes. I am sure there are other possibilities but this might help. I am lucky in that my meter is easy to get too.

Nigel says:
21 February 2014

I am with Tony, an inaccurate time switch can work for you as much as against you. Some years ago I was in the same position, with a mechanical time-switch.
Now I have a digital time-switch that switches on at 11.30pm and runs until 06.30 am GMT or 00.30 – 07.30 BST. Whilst there is no actual switching time displayed you can watch the tariff change from Tariff 1 Daytime to Tariff 2 Nighttime, and vice-versa. There is also a neon light on the storage heater output on the wall that lights up when the heater is charging on the nighttime tariff.
I set my washing machine to operate in the early morning, say 2am. Then if I need to use the tumble dryer have it finished by switch-over. Also I have usually had my breakfast and finished in the shower, 10kw instant electric, before switch over to daytime tariff.

Likewise I am surprised as a matter of good practice people do not check their time switch at the same time that they read their meter and calculate their usage.

Brian Willson says:
21 February 2014

The meter clock being wrong can be to your advantage if it switches off later than expected because you can then get cheap rate electricity at a more useable time. Inaccuracies are only a problem if the clock is switching off your cheap rate electricity earlier than planned or you find that you are not getting your full 7 hours.

Eric Partington says:
21 February 2014

An infirm and 85-year-old spinster in my village has under-floor heating on an Economy 7 timeswitch which is sealed by SSE plc. A recent gale caused a twelve-hour power-cut. When the power was restored, the timeswitch thought that day was night and vice versa, leaving her with no overnight heating of her house until an engineer could be sent out.

I have asked SSE for information about a replacement timeswitch which they can reset remotely after a power cut.

Our eco7 clock gives us cheaper electricity between about 08:30 and 17:00.
This suits us, as it’s the time when we’re using our tumble dryer…
Obviously, I prefer to remain anonymous, lest we lose this benefit!

From the comments coming in, it seems to me that having the wrong time on your time clock IS NOT A PROBLEM as long as you know when you are in the (cheap) zone. With the clock working correctly you will get cheap electricity at night when most of us are asleep Any slippage in the clock is likely to result in cheap off peak electricity being available when you are up and needing to use electricity. So if you check to make sure you know when your off peak reverts to day rate and then maximise your useage before the meter switches to day rate. For most people I would suggest, having the wrong time on your clock is a money saver, with the 7.30am switch over becoming 8.30, 9.30 or with the guy above right through to 5pm.

I would suggest there are more winners than losers on this one, AS LONG AS YOU KNOW at WHAT TIME THE SWITCHOVER IS, I certainly do not want my time clock correcting.

As an electrician I often see time clocks hours out and that is always a benefit to the customer as they get cheap power in the evening or when getting up. This is usually due to the backup battery failing in the clock and in some cases after a power cut the clock will refuse to restart and it then becomes obvious when taking the next meter readings. Surprisingly the suppliers often don’t comment even after a years worth of readings showing no daytime consumption! I am surprised there isn’t a software check in the billing program.

Adrian Hedges says:
23 February 2014

I noticed that my E10 meter was 50 minutes slow and so whilst I had religously been putting heavy drain appliances on at the correct time, I had been substantially missing out. I contacted EDF and arranged for a man to inspect it. The day before he came I saw your article in Which? and was suprised that this was not uncommon. The man came and replaced the meter as they cannot correct the time on them and the new one is already 8 minutes slow! He also told me that the time does not adjust with BST, something I was unaware of. I am surprised that when I signed up with EDF they took great pains to tell me the key facts i.e. usage rates, fixed periods, cheap rate periods etc.but omitted to tell me that the meter does not change with BST, I consider this to be a key fact.

John K says:
23 February 2014

It’s an interesting article, but it was a surprise to me, even though I’m on Economy 7. Many years ago, SSE replaced the old clock & the meter with Radio Teleswitch. Their meter in my house does not display the time at all; the meter shows the rate which is currently active – rate 1 or rate 2. Having checked it (in the morning), at my house, off peak is 00:30 – 07:30 GMT.

The only thing is that it’s dependant on the old Droitwich long-wave transmitter working! Of course, the rate could be altered without them letting me know.

The other oddity is that the timing depends on the local supplier, rather than the firm which has your contract. E.g. I use nPower for my bills, although I live in an SSE area. Normally, I read my meters once a month and send them in on-line; they check occasionally, say a couple of times each year.

This might be useful:


I understand there are less than a dozen of those old fashioned old valves left in the world to power the Droitwich transmitter and when they have been used up the existing radio controlled system dies. I suppose by then we might have a working smart meter system?

Willem says:
23 February 2014

The most simpel way is a TFR (Tonefrequent Receiver) this also is ajusted with summer and winter time. This is what they use in other European countries. It also gives cheap electricety in the weekend what is used for doing the washing, when the use of electric is lower as factories close.

Philip Owen says:
23 February 2014

I have a relative for whom having the clock put out by over 6 hours by a power cut was used to thier advantage. E7 tariffs by their nature encourage use of electricity overnight instead of during the day. But what they were able to do was do all thier washing, water heating, cooking during the day at cheap rate ! Thier night units accounted for over 70% of thier bill most quarters. My system doesnt have a clock just a radio controlled switch.

christoph says:
24 February 2014

Why is the “cheap” Eco 7 rate more expensive than the normal rate when we are trying to equal out the power station output over 24 hrs?

Every package I have seen has a cheaper night rate on economy 7 than the day rate! The day rate is usually more expensive than the single tier rate so you have to use usually at least 35% to 40% of your electricity on the night rate to make the deal cheaper than the single tier rate. My day rate with Co op energy is 13.05p and the night rate 6.48p If I just had the single tier rate all units would be at 11.26p so I save on night use age and pay more for day units, in total my average unit price is about 10p so I pay less than the single tier rate. Having solar PV now helps reduce my day usage further.

Historically economy 7 was a marketing exercise from the days when nuclear power came in 50 years ago and was a way, in conjunction with night storage heaters of soaking up the surplus electricity generated by nuclear at off peak times. Nuclear runs 24/7 and can not be turned up and down like fossil fuel or hydro. Hence the pumped storage system at one nuclear plant in Wales so the power can then be harvested when needed.