Your Economy 7 cheap hours may have moved when the clocks went back on Sunday 25 October 2026. Lots of Economy 7 meters run on a fixed internal clock that ignores British Summer Time, so the off-peak window can land an hour away from where it sat in summer. Ask your supplier for your exact times, then reset storage heater, immersion and appliance timers to match.
Why do Economy 7 times change when the clocks change?
Economy 7 gives you a cheaper unit rate for seven hours, usually overnight, and a dearer rate for the other 17. Ofgem says the off-peak period is a specified window, and its timing can vary by where you live and which meter you've got.
EDF explains that the meter usually doesn't change its own time, so your off-peak hours can differ between British Summer Time and Greenwich Mean Time. Lots of older meters stay on GMT all year. Say your window is midnight to 7am in winter. In summer it would run from 1am to 8am on your kitchen clock.
That's not true of every meter. Some older radio-controlled and smart set-ups do follow the clock change, and some older dial timers have simply drifted over the years. Don't assume. Check.
How do you find your exact off-peak hours?
Your supplier holds the definitive times for the meter at your address, so start there. They'll usually be in your online account, on your bill or in your tariff details. If not, ask, and get the answer in writing.
OVO, for example, tells customers with a smart meter it installed that off-peak times can be worked out from the first two digits of the MPAN (the Meter Point Administration Number on your bill). It adds that times can vary if your meter is traditional or was installed by another supplier. Even if you know your region's usual window, confirm it for your own meter.
You can also check for yourself. Take readings from both registers just before and just after the time you think the cheap rate starts. If the night register (it might say Rate 1, Rate 2, low or off-peak) starts climbing while the day register stops, you've found the switchover. Register labels differ between meter models, so don't assume Rate 1 is always day.
What should you reset after the clocks go back?
Anything set to run in your cheap window:
- Storage heaters. Many are wired to charge automatically when the meter switches rate. If yours run on a separate timer, line it up with the confirmed GMT window.
- Immersion heater timers. A timer that's an hour out could heat your water at the peak rate every single day.
- Washing machines, dishwashers and tumble dryers on delay timers. Make sure the cycle finishes before the off-peak window ends.
- EV chargers and home batteries. Check the schedule in the app and confirm it matches the tariff window, not just the clock on the wall.
Everything you use during the off-peak hours gets the cheaper rate, not just the storage heaters. Ordinary daytime use is still charged at the peak rate.
Is Economy 7 still worth it for you?
That comes down to how much of your electricity you use at night. Ofgem says Economy 7 could help you save if you use more electricity at night, for example for storage heaters or charging an electric vehicle. If you don't use much at night, it says you're likely to be better off on a single-rate tariff.
The catch is the day rate, which is usually higher than a single-rate price. Here's a quick way to find your break-even point:
Break-even off-peak share = (peak rate − single rate) ÷ (peak rate − off-peak rate)
Take made-up rates as an example: a 30p day rate, a 13p night rate and a 25p single rate. That gives (30 − 25) ÷ (30 − 13) = 5 ÷ 17, or about 29%. With those figures, Economy 7 only works out cheaper if more than roughly 29% of your electricity goes through the night register. Put in the rates from your own bill or quote, and compare standing charges too.
To get your night share, add up a year's night-register readings and divide by your total use. MoneySavingExpert's comparisons use Ofgem's typical Economy 7 household, which uses 3,900kWh a year with 42% off-peak. Plenty of homes are nowhere near that, especially ones with gas heating and someone in during the day.
How does the price cap apply to Economy 7?
If you're on a standard variable (default) Economy 7 tariff, you're covered by the price cap. Ofgem says multi-rate tariffs have one unit rate for peak hours and another for off-peak hours, and together they can't exceed the price cap. That means there isn't one national day rate and night rate. Suppliers can split the two differently, and prices vary by region and payment method.
Fixed Economy 7 tariffs aren't limited by the cap. You pay whatever rates you agreed for the length of the deal, so check both the day and night rates before you sign up, not just the headline night price.
What if you still have an old radio-controlled meter?
Some older Economy 7 and electric heating meters were controlled by a radio signal called the Radio Teleswitch Service (RTS). It told the meter when to switch rates and when to turn heating and hot water on and off. The switch-off began on 30 June 2025, and the final switch-off happened on 30 June 2026.
Ofgem warns that without the signal, these meters may stop working properly. Heating and hot water could be left on or off all the time, your supplier may not be able to tell your peak use from your off-peak use, and your costs could go up. Ofgem says suppliers must make sure you have a suitable meter installed without disrupting your service. They should also move you onto a suitable tariff that reflects how you use energy, or another smart tariff of your choice. The Energy Saving Trust notes Ofgem's position that you shouldn't be worse off because of the changeover.
You might still have an RTS meter if there's a separate switch box near your meter with a Radio Teleswitch label. If you do, or your heating has started coming on at odd times, contact your supplier straight away. If you rent, tell your landlord or housing officer as well, because letters about the meter may have gone to them.
What can you do if your supplier gets it wrong?
Maybe you were given the wrong off-peak times, your meter is recording at the wrong rate, or a meter swap has left you paying more. Complain to your supplier in writing and include your meter readings as evidence. Ask them to check the meter's configuration and to correct any overcharge. If it isn't resolved after eight weeks, or they send you a deadlock letter, you can take it to the Energy Ombudsman for free.
What to do next
- Get your exact Economy 7 off-peak times from your supplier, in writing.
- Do a before-and-after register check to confirm when your meter actually switches.
- Reset storage heater, immersion, appliance, EV and battery timers to the winter window.
- Work out your night share from a year of readings and run the break-even sum with your own rates.
- If your night share is low, ask your supplier whether you can move to a single-rate tariff, and compare standing charges too.
- If you think you still have an RTS meter, contact your supplier now.
- Keep your readings and correspondence in case you need to complain.
This is general information, not financial advice.