Pilot light keeps going out — what's causing it
A pilot light that won't stay lit is almost always a thermocouple, a dirty pilot jet, or a faulty gas valve. This is Gas Safe work only — never DIY on a gas appliance — but a quick description in chat helps Kevin send the right engineer with the right parts.
Make it safe — before anything else
Only Gas Safe registered engineers work on gas
Pilot lights, thermocouples and gas valves are Gas Safe work. Every KJ Plumbers engineer sent to a gas job carries a valid Gas Safe card — ask to see it.
Smell gas? Leave and call 0800 111 999
The National Gas Emergency Service is free, 24/7, and takes priority over any plumber. Leave doors open, turn the meter off if you can safely reach it, and call from outside.
Don't relight repeatedly
Every failed relight releases a small amount of gas. Two attempts is the safe limit; then ventilate and call an engineer.
What Kevin (our AI) will check first
Message Kevin and he'll ask exactly these questions before we send an engineer, so we bring the right parts on the first van.
- Boiler make, model and rough age.
- Does the pilot light for a few seconds and then go out, or fail to light at all?
- Any error code on the display?
- Any smell of gas at any point? (If yes, we stop and call the emergency line first.)
- When was it last serviced?
Common causes of a pilot light keeps going out
Failed thermocouple
The thermocouple senses the pilot flame and keeps the gas valve open. When it fails, the valve shuts off the gas seconds after lighting. £90 – £160 fitted.
Dirty pilot jet
Dust and lint block the tiny jet, giving a weak yellow flame that can't heat the thermocouple. Cleaning during a service resolves it.
Failed gas valve
Older boilers with mechanical gas valves develop internal faults; the valve won't hold open even with a good thermocouple signal. £180 – £320 fitted.
Blocked flue or draught
Wind blowing down a badly sited flue can blow the pilot out. Flue check and possibly a terminal guard resolves it.
Low gas pressure
Meter regulator failing, or a shared supply issue, drops pressure below what the pilot needs. Diagnosed with a manometer at the boiler.
Honest cost band — why we won't quote blind
Typical
£90 – £160 for thermocouple replacement or pilot clean during a service
Complex
Gas valve £180 – £320. Flue diagnosis or terminal work £180 – £380.
£50 diagnostic includes a full gas rate and combustion check — you leave with a working boiler and a written report.
Fixed £50 diagnostic
Flat fee. No hourly meter running.
Fair quote or refund
Transparent pricing — refunded if we don't fix it.
Vetted UK engineers
DBS-checked, insured, real reviews.
AI-triaged in seconds
KJ chats first so the right engineer arrives.
Related emergencies
Boiler on but no heating
Emergency guide
No hot water
Emergency guide
Boiler losing pressure
Emergency guide
See all in the emergency plumbing hub — or the leaks & water damage hub.
Areas we cover for pilot light keeps going out
Same-day across Greater Manchester and Rochdale.
Pilot light keeps going out — FAQs
Dealing with a pilot light keeps going out? Chat with Kevin now
Real triage in seconds. £50 diagnostic visit — refunded if we don't fix it.
Related hubs: emergency plumbing, leaks & water damage, all services.
Chat with Kevin about Pilot light keeps going out