A boiler is one of those things that you don’t appreciate until they break. When a boiler stops working the whole house is disrupted. Your kids won’t shower because the water is freezing and your partner is complaining because the radiators are cold.
We have all been there, and if your boiler is not firing up for central heating it can be a major pain, in this post, we will take a look at the most common faults that will stop your boiler from firing up.
The great thing about new boilers is most of them will tell you an error code on the front of them. If you then look at the owners manual for this code it will give you the reason for the boiler not firing up, the error codes make it easier for you to diagnose the problem and potentially fix your boiler.
When you know why your boiler isn’t working you can then either fix the problem yourself or call in boiler repair experts like ourselves to get the problem fixed.
Disclaimer: Boiler problems could create life-threatening situations as gas leaks can be fatal. We would always recommend calling in Gas safe engineers when fixing a boiler or installing a new boiler in your home.
Reason 1 for your boiler not firing up – Your boiler has no power
In order for your boiler to work it needs power, this power is used to fire it up so that it can heat your home. If the power is interrupted by bad weather, an outage or even if someone in your home turns it off accidentally then your boiler won’t be able to fire up for central heating.
Your boiler may have also tripped your circuit breaker so you can check to see if anything has tripped in your fuse box.
Electrical problems with boilers can sometimes be fixed by turning the boiler off and on again, or they could be more complex if the boiler has an electrical problem. If you have looked to see if anything has tripped and you haven’t blown a fuse and turning the boiler on and off doesn’t work we would recommend talking to an expert to get your boiler fixed.
To check if you can fix your boiler if the power has gone off you can reset your boiler by clicking the reset on the boiler and holding it down from 10-20 seconds depending on the brand of boiler. If this works the error message on the front of your boiler will disappear and a green light should appear.
Reason 2 for your boiler not firing up – Your boiler has no gas supply.
Your boiler will run on gas (unless you are reading this after 2025) and if there isn’t a supply of gas then your boiler will not work.
Gas supply problems can come in many forms and it could be something as simple as you have forgotten to pay your bill for that month, your gas meter could be frozen or if you have had a new boiler installed it could be that your old supply pipes can’t keep up with the demand of a newer efficient boiler.
The gas valve on your boiler could also be faulty and could be leaking. Obviously, this is a big problem so if you do think that your boiler has a problem with the gas supply you should get in touch with a gas safe engineer right away. Carbon Monoxide poisoning can be fatal so do not take the risk and call out an expert.
If you don’t suspect a leak, call up your gas provider to see if you owe on any of your bills and if you do pay them. If you are up to date with your bills you can check to see if your gas has accidentally been turned off in your own home. If neither of these solves the problem call a heating engineer out. The call-out charge isn’t expensive and could save your life.
Reason 3 for your boiler not working – Boiler Timer or Thermostat is broken.
Power outages can reset the timer on your thermostat so that it doesn’t fire up at the right time. We have seen many customers suffer from this so check for this first. Checking the time on most boilers is easy enough and a quick 30 seconds check will tell you if the boiler time is wrong or not. If your boiler timer is wrong, follow the manufacturer’s advice on how to change it.
If the time on your boiler is correct you may have a faulty thermostat that isn’t reading the correct temperature in your home so it doesn’t fire up your boiler when the temperature drops. In this case, you will need to call out an engineer to fix your thermostat.
Another reason which is simple to fix is that the temperature on your thermostat has been set to a temperature that is too low. Increase this temperature and your boiler may start firing again.
Reason 4 for your boiler not firing up – Faulty Radiators
Trapped air in your radiators can cause your boiler to not run efficiently and can cause cold radiators. To fix this problem you are going to need to bleed your radiators.
Now bleeding a radiator isn’t hard and you can do it yourself with a little know-how. We have found a good video on Youtube showing you how to do this yourself which can be seen below:
After watching the above video you should know how to lead your radiators, but if you don’t feel confident to do so please get in touch with us and we can help you out with this.
A good way to tell if air is trapped in your radiators is to touch the bottom of your radiators and then the top. The bottom part of your radiator will be warmer than the top as the air pockets will be stuck at the top causing your heating not to work as it should.
Reason 5 for your boiler not firing up your central heating – Frozen Pipes
Frozen pipes are a nightmare for homeowners in general and can cause leaks all around the house. When it comes to your boiler, the pipe most likely to freeze is something called the condensate pipe.
The condensate is often located outside of your property and it’s a pipe used by the boiler to get rid of waste. Because the condensate pipe is outside of your home it is prone to freezing.
When your condensate pipe is frozen your boiler will turn its self off to protect its self. If your boiler stops working when there is a weather change and it’s snowing outside there is a good chance that your condensate pipe has frozen.
You can thaw a condensate pipe yourself, below is a good video from Worcester showing you exactly how to do that.
Reason 6 for your boiler not firing – No pressure
A very common problem for a boiler not firing up for central heating is that your boiler is losing pressure. Domestic boilers usually operate above 1 bar of pressure and if your boiler is below this it won’t fire up.
Air in your radiators or a leak in your system will make your boilers pressure drop which will stop it from firing up. Your boiler may also not fire up if the pressure in the system is too high too.
To see what pressure your boiler should be operated at check-in your owners manual. You can then either bleed your radiators if the pressure is too high or you can repressurise your boiler to the correct levels.
You can see how to repressurise your combi boiler below:
Reason 7 for your boiler not turning on your central heating system – Faulty Burner
When your boiler burns it produces waste gases that can clog up the system. If the waste (CO2 Gas) clogs up the system it will cause your boiler to not work as it should or work at all.
A clogged system will cause an inconsistent flame which will result in your boiler not producing heat or hot water and it will reduce the life cycle of how long your boiler can last.
Unfortunately, if this is the problem with your boiler you won’t be able to fix this yourself. You should phone a boiler repair company and ask them to send out a heating engineer to fix this issue for you.
Is your boiler still not firing up?
If your boiler still isn’t firing up or you don’t have the confidence to tackle these problems call an expert like us and we will be able to help you either repair your boiler or install a new one if the problem is bad enough.
Boilers use gas so please be careful and if in doubt contact an expert rather than risking your families life. Call out charges aren’t too expensive and is worth it for peace of mind.