What model do you have?
12V power has to go to switch then to/thru both set of t-stats and then to module before 12V power is sent to gas valve and spark electrode.
Bad/loose grounds in outside compartment
Faulty thermal cut out (if you have one)
Faulty t-stat(s)
Bad module
Dirty connectors on module
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31