how to test a thermopile
They produce 750 millivolts when heated. depending on what it is in you may have to buy a adapter to test it. A Thermocouple only makes 50 millivolts. A Themopile has 15 junctions inside, where as a Thermocouple has 1. A Thermocouple should lock in within 10 seconds with a correct flame. Thermopiles may need 30 seconds. Different gas valves have different amp draws, but will be in milliamp range and drop down the voltage.
Make sure there's a PROPER flame first (like fixbear said).
A weak pilot flame may not supply enough heat to sustain a thermopile under a load.
That is with pilot load on it, but no main.
One can adjust the pilot flame to the voltage. (open)
Retrieving data ...