When a boiler stops giving heating and hot water, the most common causes are low system pressure, a power or timer problem, a frozen condensate pipe in cold weather, or a fault the boiler has locked out on. Check the display for a fault code, the pressure gauge, and that the power and gas are on. If it still won’t fire, or shows the same fault after one reset, call a Gas Safe registered engineer.
Quick checks before you call
- Is there power? Check the boiler display is lit and the fused spur next to it is switched on.
- Is the gas on? If your gas hob works, the gas supply is fine. If it doesn’t, check your gas meter’s emergency control valve is open, or contact your supplier if you have a prepayment meter.
- What does the pressure gauge say? Most boilers stop working below about 1 bar. See our guide to a boiler losing pressure.
- Is the timer or thermostat calling for heat? Make sure the clock hasn’t reset after a power cut and the room thermostat is turned up.
- Is there a fault code? Write it down. Your boiler manual explains what it means, and it helps the engineer bring the right part.
Common causes
Low pressure is the most common one. A frozen condensate pipe is a frequent cause in a cold snap: the plastic pipe that runs outside from a condensing boiler can freeze and block, and the boiler locks out. Failed parts, such as a fan, gas valve, ignition electrode, printed circuit board or diverter valve, need an engineer to diagnose and replace.
Heating works but no hot water (or the other way round)?
On a combi boiler, that usually points to the diverter valve. Read our guide to a combi boiler with no hot water.
Covering Faversham, Canterbury, Whitstable, Herne Bay, Thanet, Sandwich, Deal and Dover: see areas we cover.
Get it sorted
Call or WhatsApp Addisons Plumbing & Heating with a quick description or a photo, and we’ll tell you what it looks like and arrange a visit. Free, no-obligation quotes across East Kent. If you ever smell gas, call the National Gas Emergency number on 0800 111 999.
Quick questions
Should I keep resetting my boiler?
No. One reset is fine. If the same fault comes back, the boiler is protecting itself from a real problem, so call an engineer rather than resetting it again and again.
Is it safe to use my boiler if it keeps cutting out?
If you smell gas, see scorch marks or soot, or the boiler is making unusual banging noises, switch it off and call for help. If you smell gas, call 0800 111 999 straight away.
How quickly can you fix a broken boiler in East Kent?
Households with no heating or hot water are prioritised. Many repairs are done on the first visit; some parts need ordering.
