Mr. Heater Gas Valve Problem

67Dart273 said
It's actually a thermopile. A thermocouple is smaller and puts out less power. Thermocouples are used typically on water tanks and older pilot type furnaces with 24V valves. a thermopile is normally "fatter" about 1/2" dia. and produces more power also known as 750 millivolt

I would CERTAINLY gamble on a thermopile before I spent the money on a gas valve. It is the more likely problem, and you may need one later, if not now. Regardless of the pilot "look" I'd pull it apart and blow it out. Use shop air, IE fairly high pressure, 50psi or more if you can get it, a rubber tipped blow gun.

Typical thermopile. They are called a pile because they contain a number of thermocouples

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Typical thermocouple, about 3/16 in dia. Not what you want here
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Prices are all over the map just try and deal with someone you think you can trust

Okay. I'll look into a thermopile. (I've driven some real piles, never knew I was trusting one to heat my garage. ha ha)
I did read about the differences, I only called it a couple because the parts list I have calls it a thermocouple.
Is it generic, or should I stick with the correct replacement? I read this on GJ:

"And, finally, since both a thermocouple and a thermopile simply create a voltage difference between two wires when their ends are heated, different lengths of thermocouples will all generate the same voltage, just as thermopiles of different length. So you can use a longer thermocouple to replace a shorter one, and use a longer thermopile to replace a shorter one. They're like extension cords or garden hoses or battery booster cables in that respect. That's important to know when you're water heater's pilot light goes out and the hardware store doesn't have a thermopile of the right length. (Just buy a longer one.)"

And, I thought I was being lazy regarding checking the pilot. :rolleyes: I'll blow it out tomorrow. I have 115# of shop air.

Again, I appreciate your help. A new heater for $300 or so isn't that bad, but I like to learn and don't really want to scrap the old one if it's repairable.