Does turning your thermostat down by 1°C really save money?
Yes, turning your thermostat down by 1°C does save money. Every degree you heat your home above the outside temperature costs energy, so a lower setting means the boiler runs less.
The honest bit is the size of the saving. You'll see figures online anywhere from £50 to well over £100 a year, and they date from different price levels. So I haven't picked one. Below is a worked example at today's gas price that you can redo with your own bill in two minutes.
The sum, at today's price
On 23 October 2026, the Flexible Octopus gas rate in Yorkshire was about 7.9p per kWh (the unit rate including VAT, direct debit, from the Octopus Energy API). Your rate will be in the same area, and your bill gives the exact figure.
Rules of thumb vary on what a degree is worth, commonly somewhere between 5% and 10% of your heating use. I can't point you to one authoritative number, so the table shows both ends. The saving is only on the gas you use for heating, not cooking or hot water.
| Gas used for heating in a year | Heating cost at 7.9p | Saving at 5% | Saving at 10% |
|---|---|---|---|
| 6,000kWh (small flat) | about £474 | about £24 | about £47 |
| 10,000kWh (typical house) | about £790 | about £39 | about £79 |
| 14,000kWh (larger or leakier home) | about £1,106 | about £55 | about £111 |
These are illustrations from my assumptions, not measurements of your home. To use them, look at your annual gas use on your bill or smart meter app, take off a rough allowance for cooking and hot water, and multiply the rest by 7.9p and by 5% to 10%.
The savings are bigger in a draughty, poorly insulated house, where the heat is escaping fast, and smaller in a well-insulated one. Either way, it's a free saving, and it repeats every winter.
What about electric heating?
The same logic applies, and the pounds per unit are higher. On 23 October 2026 the Flexible Octopus electricity rate in Yorkshire was about 25.6p per kWh, against about 7.9p for gas.
A 2kW electric heater running for two hours uses 4kWh, which is roughly £1.02 at that rate. Heating a room a degree cooler for part of the day is a bigger win here than with gas. The Gas or electric? tool puts your own prices in and compares the two for you.
A boiler wastes some heat on the way, so the real gap between gas and electric is a little narrower than the raw prices suggest. It's still big.
How low is too low?
This is where I'd slow down. Saving money is no use if your home gets cold enough to harm your health.
The NHS advises heating the rooms you use regularly, such as your living room and bedroom, to at least 18°C if you can. That matters most if you're 65 or older, have a health condition, or have young children at home.
So the sensible approach isn't to chase a number. It's to find the lowest setting at which everyone in the house is still comfortable, and stop there. If you're sitting in a coat indoors, you've gone too far.
Easy ways to turn it down without feeling it
- Drop it a degree at a time. Go down 1°C, live with it for a few days, and only go lower if nobody notices. Most people adjust quickly.
- Layer up. A jumper or a blanket on the sofa changes how warm you feel more than you'd expect, and it costs nothing to run.
- Heat the rooms you use. If you have thermostatic radiator valves (TRVs), turn them down in empty rooms, and keep doors closed so heat stays where you are.
- Use a timer. Set the heating to come on shortly before you get up and switch off shortly before you leave or go to bed, rather than holding a set temperature all day.
- Check the thermostat itself. Many old thermostats are out by a degree or two. A cheap room thermometer tells you what the room is actually doing.
None of these need a plumber, and none cost more than a few pounds.
Where this fits with the rest of your bill
Turning down the thermostat tackles how much heat you use. The other lever is when you use electricity, if you're on a time-of-use tariff, and I've written about that in what's the cheapest time to use electricity in the UK. Together they cover most of what you can change without spending money.
If you want to see what an hour of electric heating costs on your tariff, and when it's cheapest, Cheap Watts will show you. Pick the appliance, and it works out the best time.
The short version
- Turning your thermostat down by 1°C does save money, commonly quoted as 5% to 10% of heating use.
- At 7.9p per kWh of gas, a typical house using 10,000kWh for heating would save roughly £39 to £79 a year.
- The NHS says to aim for at least 18°C in the rooms you use, so don't go below that if you're older or have a health condition.
- Take it down one degree at a time, and stop when anyone feels cold.
This week, check your thermostat setting, take it down by 1°C, and see whether anyone notices. If they don't, you've just earned your saving.