There are very few things more annoying in life than a broken down central heating boiler. Boilers invariably break down at the most inconvenient time—typically when the temperature outside is below zero and your bank account is running on empty. But before you call out a heating engineer, there are a few things you should check.
Mains gas boilers don’t run out of fuel because the gas supply is continuous (unless you have been cut off for any reason), but if you have an oil or LPG boiler, check that you still have fuel in the tank.
Water Pressure is Too Low
If the water pressure inside the boiler falls below a certain level, the boiler will stop working. This can happen for many reasons, but recent plumbing work is a common cause of low water pressure. For example, if you have removed a radiator from the system or you had a leak, you should always top up the water pressure inside the boiler. A failure to do so will cause the boiler to lock out. A noisy boiler is an early warning sign of low water pressure, so be alert.
Is the boiler lock out light on? If in doubt about what you are looking at, check the manual, but if the lock out light is on, press the reset button to get the boiler going again. All being well the boiler should resume normal service without any problem, but if it keeps locking out you need to call a heating engineer to identify what the underlying problem is.
Gas boilers have a pilot light, so check whether this is lit. If it isn’t, try re-lighting it. Sometimes a strong draft can blow the pilot light out, but should the problem recur, you have a more serious problem to contend with.
Check the Power
It may sound obvious, but is there any power to the boiler? Check to see if there are lights on and if there is no sign of life, try replacing the main fuse.
The room thermostat is supposed to tell the boiler when to come on. If your boiler has failed to fire up even though it would normally be on at this time, check the thermostat control panel. If it is a wireless unit, try replacing the batteries, and if all else fails, press the re-set button.
Frozen Condensate Pipe
This is a problem associated with exceptionally cold weather. A condensate pipe removes waste water from the boiler, usually into an outside drain. Unfortunately, condensate pipes are prone to freezing when the temperature drops too low. When the pipe freezes it creates a blockage and water backs up inside the boiler, triggering a lock down. The condensate pipe will need to be thawed out, but this must be done very carefully. Use warm water or a heat pad to gently thaw out the pipe, and if in doubt, call a qualified heating engineer.
Call the Engineer
Boilers are tricky things and there are many things that can go wrong with them. Once you have checked all the obvious things and the boiler still isn’t working, it is time to call out an engineer. Hopefully you have a maintenance contract and the visit won’t cost you a thing, but if you don’t, make sure you know exactly what the call-out charge is so you don’t have any nasty surprises later.
One way to prevent boiler breakdowns is to have an annual service. Regular servicing will help to prevent minor problems from snowballing into major issues, as well as make sure your boiler is safe to use.