Why does the pilot light on my furnace keep going out?
If your furnace pilot light keeps going out, it’s likely you have a broken thermocouple in your gas furnace. The thermocouple is a rod that comes into physical contact with the flame in your system. When this component is not able to detect the flame, it will close the gas valve to prevent a gas leak in your home.
How do I know if my thermocouple is bad on my furnace?
Failed Thermocouple Symptoms
- The first is signs of contamination on the tube, which can include discoloration, cracks, or pinholes.
- Next, check the wiring for any signs of wear or corrosion like missing insulation or bare wire.
How much does it cost to replace a thermocouple on a furnace?
Cost to Replace a Thermocouple on a Furnace Replacing a thermocouple costs $150 to $250, mostly due to labor time. On older models without an ignitor, it checks to make sure your pilot light is lit. If it’s not, it’ll shut the gas off.
Will a pilot stay lit with a bad thermocouple?
The job of the thermocouple is to keep the pilot lit. It does this by sending a tiny electric current to a sensor on the gas valve signaling the valve to stay open. Nothing lasts forever, and when the thermocouple wears out, the pilot won’t stay lit and your appliance won’t work.
What causes a thermocouple to fail?
Changes in temperature can cause regular expansion and contraction in metal, which will cause thermocouples to weaken over time. After enough time, metal fatigue can cause a thermocouple to break. If thermocouples start to give out unusual readings, it may be suffering from metal fatigue.
What happens if you over tighten thermocouple?
This can cause the thermocouple to either become damaged or it may damage the sensor in the gas valve. A burned out or broken thermocouple should be replaced. …
Why does my pilot light keep going out after replacing thermocouple?
Most of the time the reason a pilot wont stay lit is that the pilot orifice and pilot burner are dirty and need to be cleaned. Clean those first before doing anything else. It’s routine maintenance that needs to be done in any case.
How much should you tighten a thermocouple?
Proper tightness should be finger tight plus ΒΌ turn. Inspect thermocouple to ensure that it is fully engaged into pilot bracket.
How do you tighten a thermocouple on a nut?
To adjust the thermocouple, you must tighten the thermocouple nut with a wrench. Take care not to apply too much pressure to the nut — just tighten it slightly. Then try lighting the pilot. If the pilot won’t stay lit, replace the thermocouple with a new one of the same type.