Checking your boiler

Checking your boiler

Regular servicing could help your boiler run more efficiently – which saves you money – and unless you have a boiler care plan in place, you’ll need to call an engineer if things do go wrong. But checking your boiler’s working properly is quite easy, if you follow our simple tips and adhere to the manufacturer’s instructions:

  • Know how your boiler works
    You won’t need an encyclopaedic knowledge of boiler engineering, but reading the instructions in full can help. Learn where the switches and controls are, and what the right settings for your home should be: if you’re cold, you may have the thermostat set too low, or not have the timer set correctly.

  • Doublecheck, is it switched on?
    It’s easier than you think to accidentally turn a boiler off. Make sure it’s switched on. If it’s still not working, check your electricity supply and see if the fuse for the boiler has tripped. If you have a gas boiler, check there aren’t any service disruptions in your area; if you have an oil boiler make sure the tank tap is open on your tank is open.

  • Gently thaw your pipes
    Most combination boilers have a condensate pipe that runs outside the house. These are prone to freezing, which could stop a system working. If it’s frozen, turn your system off and defrost the pipe gently with a hairdryer, hot water, or a towel soaked in hot water. While you’re there, make sure the boiler vents are clear – and once everything’s thawed, you should be able to reset your boiler and get everything going again. Then (our top tip), ‘lag’ the pipes (insulation is a cheap purchase from DIY shops), to prevent them freezing again.

  • Check the boiler pressure
    Combination boilers sometimes stop working if there’s a drop in pressure. If the pressure gauge on the boiler shows it’s low, check to see if there’s a disruption to the mains supply in your area. If there isn’t, check your pipes and radiators for leaks. If there’s no leak, you can turn the boiler off and manually increase the pressure by slowly lifting the valve handle.

  • Bleed your radiators
    If your radiators have cold patches (especially at the top) air could be trapped in the system. Turn off your boiler; let it cool for a few hours. Then, use a radiator key to slowly open each valve: if it hisses, that’s air escaping. When water starts to drip from the valve, close it again tightly – this is called ‘bleeding your radiators’ – it helps to hold a towel under the valve to catch the drips. Check all the radiators, in turn.

The boiler’s still not working – now what? 

Now it’s time to get a registered engineer in. You can find one locally by following these links, which offer professionals who’ve registered with the appropriate organisations:



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