Going away and wondering whether to turn your boiler off?
In summer, you can normally switch off the central heating while leaving the boiler powered on for hot water and frost protection.
During colder weather, however, switching the boiler off completely could leave your home vulnerable to frozen pipes, water damage and a distinctly unpleasant return from holiday.
Here is how to leave your heating safely and efficiently while you are away.
🔑 Key takeaways:
Summer - You can usually switch off the central heating, although you may still need the boiler for hot water.
Winter - Leave the boiler powered on and use holiday mode, frost protection or a low thermostat setting.
Do not switch off the boiler at the mains during freezing weather, as this may disable its frost-protection function.
Check your home insurance policy, particularly if the property will be empty for several weeks.
Never leave a boiler operating if it has a known fault. Arrange an inspection by a Gas Safe registered engineer instead.
Should I turn my boiler off when I go away?
For most short holidays, you do not need to switch the boiler off completely.
A better approach is usually to:
Switch off or reduce the central heating.
Turn off scheduled hot-water heating if you have a hot-water cylinder.
Use your boiler or thermostat’s holiday setting.
Leave the boiler connected to its gas and electricity supplies so frost protection can operate.
The correct setup will depend on the weather, your heating system and the instructions provided by your boiler manufacturer.
Turning your heating off is not the same as turning your boiler off
This distinction causes a surprising amount of confusion.
Turning the heating off means preventing the boiler from routinely heating your radiators. The boiler remains powered and may continue to provide hot water or activate frost protection when required.
Turning the boiler off completely means shutting down the appliance, potentially including its electricity or gas supply.
During warm weather, either option may be appropriate. During freezing weather, switching the boiler off completely can disable the safeguards designed to protect it.
Some boilers have a dedicated holiday mode that switches off normal central heating while retaining hot-water and frost-protection functions.
However, the precise behaviour varies by model, so check your manufacturer’s instructions rather than relying on guesswork.
Should you turn your boiler off during summer?
During reliably warm summer weather, it is normally fine to switch off your central heating while you are away.
If you have a combi boiler, you may prefer to leave the appliance powered so that hot water is ready when you return.
Alternatively, some boilers allow you to disable the hot-water preheat or “comfort” function, reducing unnecessary energy use without shutting down the appliance.
If you have a system or regular boiler with a hot-water cylinder, you can usually switch off the scheduled hot-water heating while the house is empty.
There is little point repeatedly heating a cylinder of water for nobody, unless your system manufacturer or heating engineer has advised otherwise.
When should you not leave the boiler running?
Do not leave a boiler operating if it:
Has displayed persistent fault codes.
Regularly loses pressure.
Makes unusual noises.
Has been leaking.
Frequently locks out or requires resetting.
Has been identified as unsafe by an engineer.
The age of the boiler alone is not a reason to switch it off. A properly maintained older boiler may be safer than a newer appliance with an unresolved fault.
The Health and Safety Executive strongly advises homeowners to have gas appliances, flues and associated pipework regularly maintained and serviced at least annually by a Gas Safe registered engineer.
Should You Turn Your Boiler Off During the Winter?
During cold weather, you should generally leave the boiler powered on.
You do not need to heat an empty house as though it is hosting Christmas dinner, but maintaining some protection against low temperatures can reduce the risk of:
Frozen internal pipes.
Burst pipes and escape-of-water damage.
A frozen boiler condensate pipe.
Damp and condensation in particularly cold properties.
Your insurer refusing or limiting a claim because policy conditions were not followed.
Frozen pipes can expand and split. The damage may not become obvious until the ice thaws and water begins escaping into the property.
The Met Office recommends insulating vulnerable water pipes and tanks, particularly those in lofts, garages and other unheated areas
What temperature should you leave the heating on while away?
There is no single temperature that is correct for every house.
As a practical starting point, many households leave the thermostat somewhere around 12°C to 15°C during cold weather. A poorly insulated home, exposed pipework or a severe forecast may justify a higher setting.
However, your insurance policy may specify a particular minimum temperature or require the heating to operate continuously during certain months.
Do not assume a generic internet recommendation overrides your policy wording. Insurers may impose additional conditions when a home is empty for an extended period, often around 30 or 60 consecutive days.
The Association of British Insurers advises homeowners to check their individual policy for restrictions and requirements relating to unoccupied properties.
Can I rely on the boiler’s frost-protection mode?
Frost protection is useful, but it has limitations.
Depending on the boiler, it may only monitor the temperature inside the appliance rather than protecting every pipe throughout the property.
It may also require:
The boiler to remain electrically powered.
The gas supply to remain open.
Sufficient boiler pressure.
Working controls and sensors.
Unobstructed condensate drainage.
This means a boiler’s frost setting should not automatically be treated as complete protection for the entire plumbing system.
If external pipes, loft tanks or plumbing in an unheated garage are vulnerable, insulating them properly is just as important.
What about spring and autumn holidays?
Avoid making the decision purely according to the month.
A cold spell in April can present more risk than a mild week in October. Equally, parts of the UK can experience low overnight temperatures well outside the conventional winter period.
Check the local forecast shortly before leaving.
As a simple rule:
No frost forecast: The central heating can usually be switched off.
Frost possible: Use holiday mode, frost protection or a low thermostat setting.
Prolonged or severe cold forecast: Consider maintaining a higher minimum temperature and asking someone to check the property.
British weather does not read seasonal boiler guides, unfortunately.
Should you turn off the water supply?
Turning off the incoming mains water supply can reduce the amount of water released if a pipe or appliance develops a leak.
The Association of British Insurers recommends considering this when leaving a property unoccupied, provided it is safe and appropriate for the heating system.
However, do not drain or isolate parts of a heating system unless you understand the system or have been advised by a qualified professional. Some boilers and heating arrangements require a functioning water supply.
At minimum, locate your internal stopcock before leaving and check that it can be operated. A stopcock you discover during a burst pipe is often a stopcock that has not moved since 1997.
Holiday checklist for your boiler and heating
Before leaving:
Check the weather forecast for your home address.
Select holiday, away or frost-protection mode if available.
Reduce the thermostat rather than switching everything off during cold weather.
Cancel unnecessary heating and hot-water schedules.
Leave the boiler’s electricity and gas supplies on if frost protection is required.
Check the boiler pressure is within the manufacturer’s recommended range.
Insulate exposed pipes in lofts, garages and outbuildings.
Locate and test the internal stopcock.
Check your home insurance conditions.
Ask a trusted person to inspect the property during longer trips.
Ensure your carbon monoxide alarms are working.
Smart heating controls can also allow you to monitor the temperature remotely and warm the house before you return.
What if your boiler is old or unreliable?
Do not simply switch off an unreliable boiler and hope for the best.
If the appliance is leaking, repeatedly losing pressure, displaying fault codes or breaking down regularly, arrange an inspection before travelling.
A Gas Safe registered engineer can determine whether it is safe to leave operating and whether repairs or replacement should be considered.
Replacing a boiler solely because it is old is not always necessary. However, recurring faults, obsolete parts, poor efficiency and increasing repair costs can make replacement the more rational long-term option.
Thinking about replacing an unreliable boiler?
Heatable provides fixed-price boiler quotes online, with installation available nationwide. Answer a few questions about your home and heating system to see suitable boiler options and prices.
Final verdict
You can normally switch off your central heating during a warm-weather holiday.
During cold weather, however, it is usually safer to leave the boiler powered on and use a holiday setting, frost-protection mode or reduced thermostat temperature.
The main points are simple:
Do not disable frost protection when freezing conditions are possible.
Follow your boiler manufacturer’s instructions.
Check your home insurance requirements.
Never operate a boiler with a known safety fault.
Ask a Gas Safe registered engineer when the condition of the appliance is uncertain.
That way, the only unpleasant surprise waiting for you at home should be the state of the airport parking bill.
