thermocoupler repeatedly fails?

[mudball]

A friend's water heater has had four thermocouple failures in two years. What might be the cause? Unfortunately I cannot tell you the brand of water heater or other details except that it is only two years old (and a few thousand miles away.) Professional plumbers have been replacing these couplers, so I doubt it is an installation or cheap parts problem. Thanks for any thoughts you might share.

 

[Dunaruna]

Re: thermocoupler repeatedly fails?

My guess is chinese coupler marketed as top quality.

The coupler generates a micro-volt to activate the main burner solenoid, if the pilot light is too cold the coupler will fault out. Check for yellow pilot light flame, should be blue.

 

[SS MAYFLOAT]

Re: thermocoupler repeatedly fails?

My guess is chinese coupler marketed as top quality.

I agree on this also. I have replaced parts that was made in the USA many years ago with the foreign made parts. Sad that the foreign made stuff seems to go by the wayside sooner than should be. I've had new parts be bad right out of the box as well. Not ALL foreign made items by most countries are junk, just one particular country that was mentioned IMO.

As for the water heater, as mentioned it must have a blue flame and directed onto the TC for maximum generation of the millavolts. It is very possible that the gas valve has lost its tolerances to maintain proper operation.

The stores I maintain have gas water heaters. It seems as if the failure rate is a lot higher than ones made 10 years ago. I love the idea of job security, but constantly replacing parts that fail prematurely is not fair to the consumer.

 

[mudball]

thanks for your thoughts

thanks for your thoughts

I'll pass them along to my buddy and see what results.

 

[j_martin]

Re: thermocoupler repeatedly fails?

look for an old NOS Honeywell or Penn thermocouple. It'll be the last one you buy.

hope it helps
John

 

[chiefalen]

Re: thermocoupler repeatedly fails?

martin is correct, honeywell.