It’s a debate that comes round every autumn in homes across Oxfordshire: leave the heating on low all day, or only switch it on when you need it? For most homes with a gas boiler, using a timer to heat the house when you’re in uses less energy than running it on low all day. There are exceptions, such as damp, poorly insulated homes and heat pumps, so it pays to know which camp you’re in. Our heating engineers can help you set things up properly.
Why the timer usually wins
A home loses heat all the time, through walls, windows, roofs and draughts. The warmer the inside compared with outside, the faster it loses heat. If the heating runs all day, you’re paying to replace heat that’s constantly leaking out, even when nobody is home.
When the heating goes off, the house cools and heat loss slows. The boiler then has to work to warm it back up, but in most homes the energy needed for that is less than the energy used keeping it warm all day. That’s why the Energy Saving Trust and most heating engineers recommend heating only when you need it.
When leaving it on low can make sense
Heat pumps
Heat pumps work best running steadily at lower temperatures. If you have one, leaving the heating on for longer at a lower setting is often the right approach. Follow your installer’s advice.
Damp or condensation problems
Some older, solid-walled homes suffer from damp and mould when they’re allowed to get cold and then warmed quickly. Gentle background heat can help keep surfaces above the point where condensation forms.
Very cold snaps
In freezing weather, keeping some heat on protects pipes in lofts, outside walls and under floors. A frost setting or a low setback temperature is a sensible safety net.
People at home all day
If someone is home all day, especially older people, babies or anyone unwell, a steady comfortable temperature matters more than squeezing every penny out of the timer.
Getting the settings right
A few changes can make a real difference:
- Set your thermostat to a comfortable level and leave it there. Turning it up doesn’t heat the house faster.
- Use the timer to bring the heating on a little before you wake and before you get home.
- Use radiator valves to keep spare rooms cooler, but don’t shut them off completely in winter.
- Lower the boiler flow temperature if your engineer agrees it suits your system. A condensing boiler often runs more efficiently at a lower setting.
- Check your controls work. An old thermostat in the wrong place can keep the boiler firing when it doesn’t need to.
Our post on how to improve heating efficiency without replacing your boiler has more practical ideas.
Heating older homes in Oxford and Abingdon
Oxfordshire has a lot of period housing, from Victorian terraces in Oxford to older cottages around Abingdon and Wallingford. Solid walls and older windows lose heat faster, so these homes cool quickly once the heating goes off. The timer approach still usually wins, but it may be worth a slightly longer warm-up period. If some radiators are slow to heat, that’s often a sign of sludge or balancing problems rather than the settings.
Frequently asked questions
Is it cheaper to leave the heating on low with a combi boiler?
Usually not. A combi boiler heats the house quickly when it’s needed, so leaving it on low all day generally uses more gas overall. The exceptions are homes with damp problems or someone at home all day. Using the timer and a sensible thermostat setting is normally the cheaper option.
What temperature should I set my thermostat to?
Many people are comfortable somewhere between 18°C and 21°C. Try lowering it by a degree and see whether you notice. If someone in the house is elderly or unwell, keep it warmer. The right figure is the lowest temperature that keeps your household comfortable and healthy.
Should I turn the heating off when I go away in winter?
Not completely. Leave it on a frost setting or a low temperature so the house doesn’t drop low enough for pipes to freeze. Most boilers and thermostats have a holiday or frost mode. A burst pipe in an empty house can cause far more damage than a few days of low heat costs.
Get your heating set up properly
If you’re not sure your heating is set up to run efficiently, give us a call on 01865 817 611 or drop us a message and we’ll check your boiler and controls are working the way they should.
