How to fix a pilot light that won't stay lit
Quick answer
A thermocouple lets the pilot light stay on. When it works, it tells the thermostat to turn on the main burner, which heats the water. It's a simple part with an important job: if it fails, your water heater won't turn on.
My Pilot Light Will Not Stay Lit (5 Minute Fix)
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How a thermocouple works
A thermocouple measures temperature using two different metals joined together, usually copper and another metal. When one end is hotter than the other, it makes a tiny amount of electricity: one end sits in the pilot flame, the other in the thermostat.
The controller reads those millivolts and lets the main burner ignite. When the thermocouple fails, the pilot won't stay lit, and without a lit pilot the thermostat won't let the main burner fire.
Signs it's the thermocouple
- The pilot won't stay lit after you release the knob
- The pilot goes out every few hours
- The water slowly goes cold
Rather we did it?
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