Is it cheaper to leave the heating on low all day? We hear that question a lot once the weather turns cold across Surrey. For most homes with a gas boiler, it isn’t cheaper than using a timer. A warm house loses heat faster than a cool one, so heating it only when you need it usually uses less gas. There are exceptions, though, and a well-maintained boiler makes any setting work better. Our boiler service and repairs page explains how we keep systems running efficiently.
Why timed heating usually wins
Your home is always losing heat through walls, windows, roof and floors. The rate depends on the difference between inside and outside temperatures. The warmer you keep the house, the faster heat escapes.
If the heating stays on all day, you’re paying to replace that lost heat around the clock. If it goes off while you’re out or asleep, the house cools and loses heat more slowly. Reheating it takes some energy, but in most homes it’s less than keeping it warm the whole time.
This is backed by guidance from organisations such as the Energy Saving Trust, which recommends using a timer to heat your home only when you need it.
When leaving it on low can make sense
There are situations where constant, lower heat can be the better choice:
- Heat pumps. These run most efficiently at steady, low temperatures over long periods, and are usually designed to run that way.
- Someone is home all day. If the house needs to be warm most of the time anyway, the savings from switching off are small.
- Damp or condensation problems. Keeping a background level of heat can help in some homes.
- Very cold snaps. A frost setting or low background heat helps protect pipes from freezing.
Settings that save money without feeling cold
Set the thermostat sensibly
Many people find somewhere around 18 to 21°C comfortable. Turning the room thermostat down by a degree can make a noticeable difference to your bill over a winter, according to the Energy Saving Trust.
Use the timer well
Set the heating to come on about half an hour before you get up or get home, and to go off half an hour before you leave or go to bed. The house holds its warmth for a while after the boiler stops.
Use radiator valves
Thermostatic radiator valves (TRVs) let you set lower temperatures in rooms you use less, such as spare bedrooms. Keep doors to those rooms closed.
Check the boiler flow temperature
On a combi boiler, lowering the flow temperature that heats the radiators can help the boiler condense more of the time, which is when it’s most efficient. Some people find a setting around 60°C works well, but it depends on the home and radiators. If you’re unsure, ask your engineer at the next service. Don’t change settings inside the boiler casing.
Other ways to cut heating costs in Surrey homes
Many homes around Woking, Guildford, Camberley and Farnham are older properties or have been extended, with a mix of radiators and insulation standards. A few things help:
- Bleed radiators that are cold at the top
- Keep furniture and long curtains away from radiators
- Draught-proof doors and windows
- Top up loft insulation where it’s thin
- Book an annual boiler service to keep it burning efficiently
If some radiators never get properly warm, our guide to common central heating problems covers the likely causes.
Frequently asked questions
Does turning the heating on and off waste energy?
Not in the way people often think. Reheating a cooled house uses energy, but generally less than keeping it warm all day. The exception is homes heated by heat pumps, which are designed to run steadily, and very poorly controlled systems where the boiler struggles to reach temperature.
What temperature should I set my thermostat to?
Many people are comfortable somewhere between 18 and 21°C in living areas. Older people and anyone with health conditions may need it warmer. Try lowering the thermostat by one degree at a time until you find the lowest temperature that still feels comfortable.
Should I leave my heating on while I’m on holiday in winter?
Use a frost setting or keep it on low if you’re away during cold weather. This protects pipes from freezing and bursting, which can cause far more expensive damage than the gas used. Some thermostats and boilers have a holiday or frost protection mode for exactly this.
Will a boiler service lower my heating bills?
A service checks the boiler is burning gas cleanly and safely, and that controls are working. A boiler that’s out of adjustment or has dirty components can use more fuel than it needs to. Regular servicing helps keep it running as the manufacturer intended.
Want your heating running as efficiently as it can?
If you’d like your boiler checked or your settings looked at before winter, give us a call on 07557 373 042 or drop us a message and we’ll help you get the most from your heating.
