I have a Vermont Casting gas stove with a Honeywell VS8420 valve on it. The pilot lights fine. When I turn the knob from "Pilot" to "On", I hear a clunk and the pilot goes out. I'm getting about 27 mV at the tip of the thermocouple. I'm getting about 700+ mV at the Thermopile (between TP and TPTH). My coil resistance between TP and TH is 3.5 Ohms. I cleaned everything up but haven't been able to fix the problem. At first I thought maybe I had a bad thermocouple or thermopile, but my mV readings are good. Any ideas?