Boiler repair & heating
Boiler frost protection fault across London
After a cold snap your boiler locks out, the heating refuses to fire, and you spot an error code or a frozen white pipe outside. Our Gas Safe engineers cover London and the M25, typically reaching emergencies in 30 to 60 minutes to thaw the condensate, reset the frost protection, and stop it recurring.
Boiler locked out after a cold snap? Frozen condensate, frost-stat trips and overheat cut-outs are common in London winters. We diagnose, recover and prevent it happening again.
What we do for a frost-related lockout
Inspect external condensate pipe for ice plug, lag with foam insulation if missing, reset frost-stat and overheat cut-out, check expansion-vessel charge (cold weather often exposes a marginal vessel), and run a full FGA before signing off.
Common frost-related faults
F22 / FH1 / EA338 lockout overnight
Condensate pipe outside has iced up. Pour warm water on it for a temporary fix; we lag it properly to prevent recurrence.
Boiler won't fire below freezing
Frost-stat is doing its job. If it's nuisance-tripping above freezing, the sensor has drifted.
No central heating but hot water works
Diverter valve has stuck during the cold snap. Often a free recovery before quoting for replacement.
Heating cuts in and out cycling fast
Frost protection mode interfering with normal operation. Reset and recommission.
What it costs (indicative)
Most frost-related recoveries complete inside the one-hour minimum labour charge. Lagging materials charged at trade plus 30%. Full pricing.
When to call us
- ✔ Your boiler has locked out after temperatures dropped below freezing.
- ✔ The external condensate pipe is uninsulated.
- ✔ Your boiler has frost-related lockouts year after year.
- ✔ You're a landlord with tenants reporting cold-snap heat loss.
Need a 24/7 emergency engineer?
30 to 60 minute response across every London borough. Gas Safe registered. 12-month workmanship guarantee.
FAQ
Boiler frost protection fault: your questions
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Need boiler frost protection fault now?
30 to 60 minute response across every London borough. Gas Safe registered. 12-month workmanship guarantee.