Home Improvement

What to Do When Your Boiler Switches Itself Off

We in the 21st century live a much more comfortable life than those of our ancestors who had to endure cold homes and chilly nights. We savour the fact that we can ramp up the heating in our homes and run a hot bath and bask in bliss… until the boiler decides to completely shut down, the warmth evaporating. Luckily, there are some things you can do to get your boiler back in working order.

So, if:

  • Your boiler keeps cutting off;
  • You wish to find out the reason; 
  • You want to know if it is possible to fix the problem yourself,

Then you are in the right place! Keep reading to find out why your boiler switches itself off.

Keeping up the pressure 

Boilers need a sustained amount of water pressure, in order to run properly. If the pressure is too low or too high, the boiler will turn itself off. Boilers usually run best between 1-1.5 bar units, so check the gauge at the front of the boiler to make sure that the pressure is normal. 

If your pressure is too low, it could be because of a leak somewhere in the system, or because you recently bled your radiators. 

Spotting a leak is easy, just look for any damp spots underneath your boiler, near your radiators or around any connecting pipes. Epoxy putty can be a great temporary fix for leaky pipes, but something more substantial like clamps will be more permanent. They are also quite simple to fit. 

Unfortunately, if the leak is from somewhere within the boiler or the pipes that surround it, you will need to call a gas safe engineer to fix the problem, as it would be illegal for you to do it yourself.

Repressurising your boiler 

After fixing any potential leaks, the next step is to repressurise the boiler. Repressurising is usually a simple five-minute procedure, but do check your boiler’s manual, as there are different models, which may require extra steps in repressurising.  

  1. Turn off the boiler and allow it to cool down for a few hours before you begin; 
  2. Next, you will have to open the filling valves, turning the handles attached until you hear rushing water. With certain models, you will have to open the valves using a screwdriver, or a key that comes with the boiler; 
  3. Keep an eye on the pressure gauge until you reach a pressure between 1-1.5 bar; 
  4. As soon as you do close the valves and switch your boiler back on; 
  5. Monitor it over the next few days, making sure that the pressure remains consistent. 

If your boiler keeps losing pressure, calling an engineer would be your best option, as you may have an internal problem with the boiler.

Thermostat issues

Thermostats are very useful, being able to monitor the temperature of your home and adjust the central heating based on your temperature preference. However, if your thermostat is a particularly old model or faulty, they may not be able to accurately determine the temperature. This can cause your boiler to fire up and then cut out when it’s not supposed to. The best way to fix this is to simply replace the thermostat.

You may also like:
Home Improvement
My Thermostat is Not Working. What Should I Do?

There are a variety of different thermostats available, with the most basic ones available at a very reasonable price. You can also opt for a smart thermostat, which offers a range of benefits. Some are able to learn your habits and monitor which rooms need the most heating and adjust accordingly. This can save you money in the long run, so if you are able to put up the actual cash, a smart metre can be a lifesaver. 

Frozen pipes

During especially harsh winters, a small pipe on the outside of your house, called condensate pipe, can become frozen. The pipe carries the acidic water away from your boiler and deposits it into a drain. When the pipe freezes, the water inside also gets frozen, which can cause water to get backed up into the boiler. Eventually, the boiler will shut itself down in order to protect itself from damage. 

Check your home’s condensate pipe to make sure it’s not frozen. If this is the case, relinquish their icy bonds with some warm water and reset your boiler.

If you have problems locating the condensate pipe, check out our dedicated post where we explain where is the condensate pipe on a boiler.

Trapped air

Another problem that appears frequently is trapped air in your boiler system, which can lead to an increase in the boiler temperature. As a result, it will shut itself off. To alleviate this problem, you should bleed the radiators around your home:

  1. Take a screwdriver or a radiator key if you have one, and loosen the valve at the top of your radiator; 
  2. You will hear a hissing noise, along with some water, so remember to bring a container;
  3. Once it has stopped hissing, close the valve;
  4. If the hissing only persists for a couple of seconds, it is unlikely that trapped air is the cause of your boiler issues;
  5. Repeat the process with every radiator in your house and hopefully, the boiler will be back to working order.

If you want to know more information on how to bleed your radiators, we suggest checking our dedicated post.

You may also like:
Home Improvement
Why Is My Radiator Cold at the Bottom?

Calling in the experts

For some boiler issues, regardless of your determination, you will not be able to fix them by yourself and must call a gas safe engineer. If you don’t want to be in the same situation again in the future – we’ve got you covered with a boiler cover care plan that includes annual boiler service and repair. Plus, if you decide to get a new boiler, check our article on how much to install a boiler.  

  • Short-cycling – Your boiler keeps a reservoir of water heated at all times, periodically switching on and off to keep it heated. If your boiler is too powerful for your home, it can do this repeatedly, leading to damage to your fuel exchanger, a costly piece of equipment to replace. 
  • Water supply – If water isn’t properly supplied to the boiler, it will shut itself off to protect from overheating. 
  • Fuel supply – May need to check with your supplier whether there are any problems. 
  • Heat exchanger – Exchanges heat between water and gas, while not allowing either to come in contact with each other. If the heat exchanger is broken, call an engineer for a replacement. Unfortunately, it can be expensive.

Experiencing problems with your boiler?

There is nothing worse than heating problems on a cold winter day, or a lack of hot water after a long work’s day. That is why Fantastic Services is here to help you with your faulty appliance!

The Gas registered engineers we work with respond to emergency calls and can fix your heating and hot water system of any brand and complexity. With every boiler repair, you get a 12-months guarantee on the performed work. So what are you waiting for? Book your boiler repair service, today!

Need a professional?

Find a Gas certified technicians near you!

Add a valid postcode e.g. SE1 2TH


  • Be as thorough as you can when inspecting your boiler and go through every possibility, because there are many things that can go wrong with them;
  • Keep an eye out for any telltale signs that might give you a clue as to what might have gone wrong, such as damp spots and frozen pipes; 
  • Most importantly, when in doubt, call a gas safe engineer. There are certain issues that you won’t be able to fix by yourself, and calling in a professional will always be your best option in these cases. 


Did you find this post useful? Share your thoughts in the comments down below!

Image source: shutterstock/Alexisaj

5 1 vote
Article Rating
Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x