When the heating or hot water stops, it's not always a major fault. Before you book a call-out, run through these simple checks. None of them involve opening the boiler, and if they don't fix it, you'll be able to tell your engineer exactly what you've already tried.
1. Is there power to the boiler?
Check the display or lights on the boiler. If it's completely dead, check the fused spur switch beside it and your fuse board for a tripped switch.
2. Is the gas on?
Check that other gas appliances, like a gas hob, are working. If nothing has gas, check your meter and, if you're on pay-as-you-go, your credit. If the gas supply is off to the whole house, contact your gas supplier.
3. Check the boiler pressure
On most combi and sealed-system boilers the pressure gauge should read around 1–1.5 bar when the system is cold. If it has dropped below 1 bar, the boiler may have locked out. See our guide to fixing low boiler pressure.
4. Check the thermostat and timer
It sounds obvious, but timers often reset after a power cut or when the clocks change. Make sure the timer is set to "on", and turn the room thermostat up a few degrees above the current room temperature.
5. Reset the boiler
If the boiler shows a fault code or a red light, note the code first, then try the reset button once. Check your manual for what the code means. If the boiler locks out again straight away, stop resetting it and call an engineer.
6. Check for a frozen condensate pipe
In very cold weather, the plastic condensate pipe that runs from a condensing boiler to an outside drain can freeze, which stops the boiler working. You may hear a gurgling sound. Pouring warm (not boiling) water along the outside section of the pipe can thaw it. Then reset the boiler.
7. Heating works but radiators are cold at the top?
That's usually trapped air. Bleeding the radiators with a radiator key should help. Remember to check the boiler pressure afterwards, as bleeding lets out a little water.
When to stop and call an engineer
- The boiler keeps locking out or showing the same fault code
- You hear loud banging, whistling or kettling noises
- There's water leaking from the boiler
- The pilot light or flame keeps going out
Never remove the boiler casing yourself. By law, only a Registered Gas Installer can work on gas appliances in Ireland.
If you smell gas, turn off the gas at the meter if it's safe to do so, open windows, don't use light switches or naked flames, leave the property and call Gas Networks Ireland on 1800 20 50 50.
Still no heat? GB Gas Services offer fast boiler repairs across Dublin. Book a repair or call 0872 855 624.