Pilot Light Keeps Going Out: Common Causes and Fixes
If you're relighting your furnace or boiler's pilot light every few days (or every few hours), something is causing it to go out — and it's rarely random.
Common Causes
A Dirty or Misaligned Thermocouple
This small safety sensor detects whether the pilot flame is lit. If it's coated in soot or bent out of position, it can "think" the flame is out and shut off gas flow even when the pilot is burning fine.
A Draft
Air leaks near the unit, a nearby vent, or even a door slamming can blow out a pilot flame — especially in older systems with an open pilot design.
A Weak or Dirty Pilot Orifice
If the pilot flame looks small, flickering, or more yellow than blue, it may not be getting a clean, steady gas supply.
A Failing Gas Valve or Thermocouple Wiring Issue
These require professional diagnosis and replacement.
What the Flame Color Tells You
A healthy pilot light burns steady and blue.
What You Can Safely Check Yourself
Follow Your Manual's Relighting Steps
Check your furnace or boiler manual for the pilot relighting instructions specific to your model — most systems have a reset button and clear steps. If it won't stay lit after a couple of attempts, stop trying and call a technician rather than repeating the process.
When to Call a Professional
If the flame is yellow, if it goes out repeatedly even with no obvious draft, don't keep relighting it yourself — this points to a component that needs proper diagnosis.
Don't keep relighting it. Call a licensed HVAC technician right away.
Pilot Light Won't Stay Lit?
Air 1 Mechanical services both furnaces and boilers & fireplaces — call for same-day service.
Serving Arlington, Falls Church, Alexandria, and surrounding Northern Virginia communities.
