If you’re planning to go away over Christmas or New Year, managing your combi boiler and radiator settings properly is essential to prevent frozen pipes and avoid costly boiler repairs. Combi boilers are an excellent choice for home central heating and hot water as they heat water on demand without needing a storage tank. However, leaving them idle in freezing weather can lead to issues. Here’s a simple guide to keep your boiler running smoothly and your home protected while you’re away.
1. Don’t Turn the Boiler Off Completely
Turning the boiler off completely while you’re not at home might seem like a good way to save energy and money, but it’s not a good idea. This is because it can cause pipes to freeze if the temperature drops below freezing. Frozen pipes can burst, leading to extensive water damage and costly repairs. Instead, leave your combi boiler on and set it to a low temperature or a specific frost protection mode (if available).
2. Use the Frost Protection Setting
Most modern combi boilers come with a frost protection feature, which activates the boiler if the internal temperature drops below a certain threshold (usually around 5°C). This ensures that your pipes remain warm enough to prevent freezing, even if the heating isn’t fully running.
- Check your combi boiler manual to locate and enable the frost protection setting. If you have had a boiler service recently, this should already have been done.
- Ensure the boiler power supply is turned on while you’re away so this feature functions as intended.
3. Lower the Thermostat
Set your thermostat to a low but safe temperature, around 10–15°C is ideal. This keeps the house just warm enough to prevent freezing without wasting energy. If you have a programmable thermostat or smart controls, you can set it to maintain this temperature consistently while you’re gone. Some smart thermostats can even allow you to monitor and adjust settings remotely via an app.
4. Check the Boiler Pressure
Before leaving, ensure your boiler’s pressure is within the recommended range. A low-pressure reading can affect the boiler’s performance and efficiency.
5. Leave Radiator Valves Open Slightly
Radiators are an integral part of your heating system, so they also need attention. Leave the radiator valves (TRVs) open slightly, ideally at the frost protection or low setting. Closing them entirely can restrict water flow, creating cold spots and increasing the risk of frozen pipes. By keeping the valves slightly open, warm water can circulate through the radiators when the heating activates.
6. Insulate Vulnerable Pipes
Pipes in exposed or unheated areas, such as attics, basements, or external walls, are particularly susceptible to freezing. Before leaving, ensure these pipes are well insulated using pipe lagging (foam tubes that are inexpensive and easy to install). Additionally, leave cupboard doors under sinks open to allow warm air to circulate around any pipes inside.
7. Consider a Boiler Service before Going Away
A poorly maintained boiler is more likely to break down, especially during winter. If your annual boiler service is due, schedule it before you leave. A Gas Safe certified heating engineer will ensure your boiler is functioning efficiently and its safety systems, like frost protection, are working correctly.
8. Turn off the Water Supply (optional)
For extra precaution, particularly if you’re going away for an extended period, consider turning off the main water supply and draining the system. This eliminates the risk of a major leak if something goes wrong. However, if you choose this option, ensure the boiler’s frost protection still operates and follow the boiler manual’s guidelines.
Properly managing your combi boiler and radiator settings while you’re away in winter is essential to protect your home and central heating system. Instead of switching the boiler off entirely, use frost protection settings and set the thermostat to a low but safe temperature. Insulating pipes and keeping radiator valves slightly open will help prevent freezing and ensure your system runs efficiently. By following these simple steps, you can enjoy your time away with peace of mind, knowing you won’t return to a freezing house or the headache of burst pipes.
