If your boiler suddenly decides it doesn’t want to fire up, it doesn’t always mean something major has gone wrong.
A lot of the time, there are a few simple things worth checking first. You don’t need to take anything apart or start pressing every button on the boiler, but a couple of basic checks can sometimes point you in the right direction.
Start with the thermostat
First thing I’d check is whether the thermostat is actually asking the boiler to come on.
Turn the temperature up above the current room temperature and see if there’s any response from the boiler.
If you’ve got a timer, programmer, Hive or another smart control, check that the heating is actually set to be on.
It sounds basic, but controls are a very common reason for people thinking the boiler itself has failed.
If your hot water is working but the heating isn’t, that can also point you more towards the heating controls or heating side of the system.
Check the boiler pressure
If you’ve got a sealed heating system, have a look at the pressure gauge or the pressure reading on the boiler.
As a general guide, a lot of systems sit somewhere around 1 to 1.5 bar when cold, although this does vary depending on the boiler and system.
If the pressure is too low, some boilers will stop working and show a fault code.
If you’re having to top the pressure up regularly, though, that’s not something I’d just keep doing. There’s normally a reason for the pressure dropping and it’s better to find the cause.
Is there a fault code on the boiler?
If the boiler is showing a fault code, take a photo of it or write it down before doing anything else.
The code can be useful when I’m fault finding because it gives me a starting point.
It’s worth remembering that a fault code doesn’t always mean the part mentioned in the manual has definitely failed. It normally tells us what the boiler has detected, and the actual cause still needs checked properly.
Check whether the boiler has power
Have a look at the display.
If the boiler is completely dead, check that the fused spur hasn’t been switched off and whether the rest of the house has power.
If a fuse keeps blowing or a circuit keeps tripping, don’t just keep resetting it. That needs properly checked.
One reset is enough
If the boiler manufacturer allows a user reset, trying it once is reasonable.
What I wouldn’t recommend is resetting it over and over again every time it locks out.
If the same fault keeps coming back, the boiler is doing it for a reason. A reset might get it running temporarily, but it hasn’t actually fixed anything.
Is it the heating, hot water, or both?
This is always useful to know before I come out.
Have a quick check and see whether:
- the heating isn’t working but the hot water is
- the hot water isn’t working but the heating is
- neither is working
- the boiler starts and then cuts out
- the fault only happens occasionally
That information can make fault finding a lot quicker.
What about cold weather?
In very cold weather, an external condensate pipe can freeze and cause some boilers to lock out.
If you can safely see the pipe outside and it looks frozen, follow the boiler manufacturer’s instructions.
Don’t remove the boiler casing or start dismantling anything internally.
When should you stop checking?
If you’ve checked the thermostat, pressure, power and any fault code and the boiler still won’t fire, that’s normally the point to get it properly looked at.
I’d also recommend booking fault finding if the boiler:
- keeps locking out
- keeps losing or gaining pressure
- makes unusual noises
- fires up and then shuts down
- needs resetting regularly
- is leaking water
And if you can smell gas, don’t try to diagnose the boiler yourself. Turn the gas off at the emergency control valve if it’s safe to do so, ventilate the property and call the National Gas Emergency Service on 0800 111 999.
Boiler fault finding in Fife
If your boiler isn’t firing up and the basic checks haven’t sorted it, I can carry out fault finding and repairs across Dunfermline and Fife.
I’ll work through what the boiler is actually doing, test it properly and explain what I’ve found before any repair is carried out.
Evening appointments are available Monday to Friday, with weekend appointments available on Saturday and Sunday.
Need your boiler checked? You can send an enquiry through the website and include the boiler make, model and any fault code you can see.
Boiler repairs in Fife · Boiler repair in Dunfermline · Request a fault-finding appointment