Is It Safe To Turn Off A Combi Boiler?

Most homeowners these days prioritise saving money with the high cost of living.  Because the heating bill is such a large part of that expense, it’s no surprise you may be looking for ways to reduce the gas bill by turning off your combi boiler.  Here, we look at whether it is safe to turn off a combi boiler and is there a benefit to it.

Is It Safe To Turn Off A Combi Boiler?

Turning your combi boiler off is perfectly safe but not for long periods. For short periods, turning off your boiler saves money when compared to leaving it turned on when you’re not home. However, leaving your boiler switched off for long periods can cause some parts inside to seize up, especially with modern boilers. 

If you’re going away on holiday, you don’t need to switch your boiler off completely because it should have a summer function built in where only the hot water part of the boiler is on and the heating element is in ‘rest mode’.

is it safe to turn off a combi boiler?

Turning the boiler off in winter

It is not a good idea to turn the boiler off in the winter months, even if you will be away for long periods.  Most boilers have a frost setting to ensure the pipes don’t freeze when the temperature outside drops.  Switching off the boiler means this safeguard isn’t there anymore.

The good thing about combi boilers is that you can still run the central heating with the cold water turned off.  By shutting off the cold water supply, the combi boiler will still keep the heating system running.  So, again, you shouldn’t need to turn off the boiler.

image showing a hand in yellow glove switching a boiler off

Can I turn the boiler off when on holiday?

Turning off your boiler while you are away from home can be beneficial in the summer.  You won’t need hot water or heating while you’re away, so the boiler can be switched off until you come back home.

However, as mentioned earlier, it is generally recommended that you do not turn off your boiler if you go on vacation during the winter, or during longer cold spells. 

This is because, without the safeguard of frost protection, your pipes may freeze and cost you time and money to fix central heating problems when you return. It is a better idea to leave your boiler on and set the room thermostat to a lower temperature, say around 14⁰C, to ensure the system still works when you get back home.

Should You Turn Your Boiler Off At Night?

Deciding whether to turn your combi boiler off at night can depend on a few factors. One consideration is the cost of leaving the boiler on overnight. If you have a programmable thermostat, you can set the temperature to a lower setting while you are sleeping to save on energy costs.

This will allow the boiler to continue running at a lower capacity, providing a consistent supply of hot water and maintaining a comfortable temperature in the home.

On the other hand, turning off the combi boiler at night can be a good option if you are going to be away from home for an extended period of time. Shutting off the gas supply to the boiler will prevent any potential accidents or damage from occurring while you are away.

In this case, it is important to properly turn off the boiler and follow the manufacturer’s instructions or consult a professional to ensure it is done safely.

If the weather is warm and you won’t need heating and, more relevantly, hot water then it is fine to switch the boiler off overnight.  Usually, in the summer, the mains water isn’t that cold anyway. 

This way you can save energy because the boiler won’t be using its preheat functions to warm the water up beforehand.

Leaving the boiler off for long periods

If you have an old boiler, you can turn it off but for best results, turn it on once every few weeks for short bursts. 

Although this requires some effort, it will prevent you from having to get a repairman out when the cold weather arrives, due to parts seizing up, radiators no longer working and being left with cold water in the winter.

image showing combi boiler being switched off and a hand switching fuse spur off

Will turning off the boiler save me money?

It can definitely save on energy bills as there is no gas being used for water or central heating.  Some family members tend to feel colder than others or their room can get particularly cold.

 So turning the boiler off will mean the whole house isn’t being heated unnecessarily.  You can put an electric heater in colder parts of the house if needed.

But in most cases, it is better to keep the boiler on but adjust radiator settings in each room.  If you need to use the bathroom in the middle of the night but the boiler is switched off, is not a pleasant experience.

Can turning the boiler off cause problems with central heating?

Certain areas of the central heating system where issues can occur if not used for long periods is with limescale build up. The deposits can settle because there is no movement of water. 

image of a boiler pump

Water pump valves becoming seized up are also common. These valves can become stuck if the central heating system is not used. This is a costly repair.  But you shouldn’t have this problem with relatively new boiler systems.

Alternative to turning off the boiler

If you are considering turning off your combi boiler but are unsure if it is the best option, there are a few alternatives you can consider. One option is to use a programmable thermostat to lower the temperature setting while you are sleeping or away from home.

This can help to save on energy costs while still providing a consistent supply of hot water and maintaining a comfortable temperature in the home.

Another option is to consider installing a timer or smart controller for your combi boiler. These devices allow you to set specific times for the boiler to turn on and off, allowing you to better control when hot water and heat is being produced.

This can be a good option if you have a consistent schedule and want to optimize energy usage

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