No Heating in Cold Weather? What to Check First

The first genuinely cold morning of the year is when the North East finds out whether its heating survived the summer. Boilers sit idle for months, then get asked to work hard overnight, and the weak ones give up. If you have woken up to no heating, work through this before you ring anyone.

Start with the boring stuff

A surprising number of no heating call outs are none of these things, so rule them out first:

• The thermostat. If it has batteries, change them. Flat batteries in a wireless thermostat mean the boiler never gets told to fire.
• The timer. Clocks changed in October. If your programmer did not change with them, the heating is coming on at the wrong time.
• The gas. Check a gas hob lights. If it does not, the problem is the supply, not the boiler.
• The power. Check the fused spur next to the boiler and the consumer unit.

Also worth a look: what the thermostat is actually set to. Plenty of "not warm enough" calls turn out to be a setting rather than a fault, and our guides on what temperature to set your boiler and whether to leave the heating on all day cover what the numbers should be.

Check the pressure gauge

Most combis want between 1 and 1.5 bar when cold. If the needle is sitting in the red at the bottom, the boiler will lock out rather than fire. Topping up is straightforward, but pressure that keeps falling means something is losing water. Our guide on boiler pressure that keeps dropping covers what that usually is.

Look for a fault code

If there is a code on the display, that is the boiler telling you exactly what is wrong. Look it up in our boiler error code guide, or go straight to the common ones: Baxi E133, Vaillant F28 and Worcester Bosch EA. All three are ignition faults and all three spike in cold weather.

The one that is almost always the culprit in a cold snap

A frozen condensate pipe. Modern condensing boilers push acidic waste water out through a plastic pipe, and if any of it runs outside, a hard frost can freeze it solid. The boiler detects the blockage and shuts down to protect itself. You will often hear a gurgling noise before it stops.

It is one of the few boiler faults you can genuinely fix yourself with a jug of warm water. Our guide on how to thaw a frozen condensate pipe walks through it safely.

Heating on but rooms still cold?

That is a different problem. If the boiler fires but the radiators are lukewarm, cold at the bottom, or take an age to warm through, the boiler is fine and the system is clogged. Years of sludge build up restrict circulation. See central heating slow to warm up and radiators cold at the bottom.

When to stop and call someone

Stop immediately and ring the National Gas Emergency Service on 0800 111 999 if you smell gas. Otherwise, call an engineer if the boiler is locking out repeatedly, if pressure will not hold, or if you have a vulnerable person or young children in the house and it is genuinely cold. Do not spend two days without heat trying to save a call out fee.

Ringing someone you have not used before? Check their Gas Safe ID and the categories on the back of the card. Our guide on how to find a Gas Safe engineer you can trust covers what to ask and what to walk away from.

We cover Sunderland, Durham, Washington, Houghton le Spring, Newcastle and the wider North East, and we keep common parts on the van so most repairs are done in one visit. If it has already broken down more than once, this explains why it happens in the first cold snap and what prevents it.