Hey all, I have a question for you. I dont work on Millivolt systems very often, and would like to get some pointers on how to check these systems properly.
If I take my VDC reading with the pilot on, from generator lead to generator lead, while hooked up to the gas valve, I have 650 MV. When the stat is made, I drop to 250. Is this 250 the left over MV?
Also, how do I check MV drop in a system, and what is the Max that you usually allow without repairing the resistance problem? Do I have to isolate the circuit? Can I take an ohm reading instead?