I have a gas valve that opens and lights then shuts off within a few seconds. Thermostat calls for heat and everything seems normal right up until the gas valve opens. It shuts shortly after and then the ign control shuts off HSI and tries the cycle again and again. I have got it working again after i did some cleaning and inspecting. Turns out the old WWII technique of tapping the valve got it to work.
Could this be a valve going bad?
Valve part# 7707-326
Ign board #1474-004
Earlier this year I had to replace the HSI as the old one had a crack and would not work sometimes.