Boiler not firing up for heating — work through this list
Before anyone charges you, half of the no-heating calls we take can be narrowed down over the phone. Batteries, schedules, pressure and frozen condensate account for a huge share of winter callouts.
Work down this list. If you get to the end and it still will not fire, it is a genuine fault and we will get someone out.
Try this first — free
Checks you can safely do yourself
Thermostat batteries and schedule
Wireless stats lose their pairing and their batteries. Replace the batteries, turn the target temperature well above room temperature and listen for the boiler.
Pressure at 1.2 bar
Most modern boilers will not fire below 0.5 bar. Re-pressurise using the filling loop.
Frozen condensate pipe
White plastic pipe running outside. Pour warm water along it. This is the number one January no-heat cause in the Midlands.
Power and gas
Check the fused spur, check the RCD, and check other gas appliances such as the hob still work — a prepayment meter running out is more common than you would think.
Never remove the boiler casing or touch gas components yourself — that's illegal as well as dangerous. Anything behind the front cover is Gas Safe work.
If that didn't fix it
What it usually turns out to be
Frozen condensate
Free if you can thaw it yourself. We also re-route or lag it so it does not happen again.
Free – £190
Faulty thermostat or wiring
Cheap parts, quick job, often mistaken for a boiler fault.
£120 – £280
Gas valve fault
More serious and more expensive; usually a replacement decision point.
£350 – £550
Ignition electrode or PCB
Electrodes are cheap, PCBs are not.
£160 – £500
Failed diverter or pump
Boiler fires for water but not heating, or nothing at all.
£220 – £420
Prices inc VAT and include our £99 diagnostic. We confirm the price before any work starts — no surprises on the invoice.
Straight talk
When we'd tell you to replace instead
- A gas valve or PCB has failed on an out-of-warranty boiler
- The boiler is 12+ years old and this is the second winter breakdown
- Parts are obsolete for the model
No heating at all in winter is a same-day priority. Call rather than message and we will fit you in.
Book it
Get your price now
Step 1 / 5
60 second boiler quote
No callbacks unless you want one
What can we help with?
Pick the option that fits — we'll tailor the next questions.
Frequently asked questions
Why is there no heating but I have hot water?
Usually the diverter valve staying in the hot water position, a failed thermostat, or a motorised valve stuck on a cylinder system.
How do I thaw a frozen condensate pipe?
Warm — never boiling — water poured slowly along the external pipe, then reset the boiler. If it refreezes, the pipe needs re-routing or lagging properly.
What do you charge to come out?
£99 inc VAT diagnostic including the first 30 minutes. If you go ahead with a new boiler with us, we credit it against the install.
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