No Power To Your Boiler? These Checks Could Fix It

If you’ve got no power to your boiler (or even your timer and thermostat), I can help you.

There are a few reasons why you may have no power to your boiler. Some you can check and fix yourself. For the other’s, you’ll need a gas safe registered heating engineer to do them for you.

So let’s start with the checks you can do yourself.

Checks You Can Do If You Have No Power To Your Boiler

1. Check your fuse-board (also called a consumer unit)

Your fuse board is what controls the electricity to your property. One of the fuses may have tripped which would cause your boiler to lose power.

Lots of fuse boards look like this one in the picture. When the switch is pointing down, it means that circuit is off. When it’s pointing up, it means it’s on.

So if there’s no power to your boiler, one of those switches may be pointing down. If you flick it back up, it may restore power to you boiler and fix the problem.

If you don’t know where your fuse board is, you can look near the entrance of your property. They’re usually installed quite high up, like this one in the picture. If it’s not there, it’s usually in the cupboard under the stairs.

Open the flap and look for a fuse pointing down in the off position. Lots of modern fuseboards have each circuit labelled, like the one in the picture. You can see the “water heater” fuse that supplies the boiler is pointing down, which means it’s off. If you flick it up to the top position, you will restore power to that circuit and may put power back to your boiler.

2. Check your boiler fuse isn’t blown

You can check this by finding the switch that turns your boiler on and off.Most likely, it’ll be next to your boiler – or very near by. If it’s not there, look in your airing cupboard where your hot water tank is (if you have one). It should be in that cupboard somewhere.Remove the fuse by levering out the fuse holder with an electrical screwdriver or similar non-conductive object (don’t use metal kids!), then taking the fuse out.Your fuse should look like this and be rated 3 amp (3A). You can replace this fuse with a new one to see if that solves the problem of your boiler having no power.

Tried both of these checks and still no power to your boiler?

Here are more checks a good heating engineer can do:

3. Check the boiler’s internal fuse (or fuses).

Most boilers have at least one built in fuse. Others can have 3 or 4. If you have no power to your boiler and have tried the first 2 checks, the next thing to do is to check the boiler’s internal fuses.

As a homeowner, this check – and all the other checks except 1 & 2 – are not safe for you to do. So you will need to find a local Gas Safe Registered heating engineer to do them for you. Boiler fuses look a bit like this and can sometimes blow for no reason, other than age. Once your heating engineer has changed the internal fuses, they will need to test your boiler to make sure it doesn’t blow any fuses again.

If it does, it means something faulty in your boiler or heating system is making the fuses blow.

4. Check the boiler’s circuit board

If all the fuses are ok, but there’s still no power to the boiler, it’s likely that the circuit board on your boiler (also called the PCB) is faulty. If this is the case, your heating engineer will need to replace it with a new one. Sadly, this isn’t usually a cheap job as circuit boards can cost between ?80 and ?250 depending on the boiler you have – plus your heating engineer’s labour.

Important note: Sometimes another faulty component in your boiler will cause the circuit board to break. The usual suspects are pumps, fans, and mechanical timers. When these fail, they can pass excess current around your boiler’s circuit board, overload it, and break it.

So make sure your heating engineer tests these components before fitting the new circuit board.

5. Does your boiler keep blowing new fuses?

If it does, there’s probably a faulty component on your heating system that’s short circuiting. The most common are either the pump, the boiler’s fan, or a mechanical timer clock. With some testing, a good heating engineer should be able to isolate the cause of the problem.