Originally Posted by jpopenhagen
Yes, the fan will come on then you can hear it trying to ignite. It does this 3 times then the fan will shut off.
BTW... All other gas appliances are working, i.e. refer, stove/oven. Also I only turn on one propane tank at a time.
A guess. If the on-off switch contacts are a bit dirty/corroded then the control may be seeing low voltage during the temperature setpoint off cycle which could cause a lockout of the gas solenoid valve.
A long shot, but simple to try. Try clicking the on-off switch back and forth quite a few times in succession to help clean the contacts.
Alternatively you may be able to CAREFULLY use a small screwdriver to move the closed contacts of the on-off switch ever so slightly against each other to scrub them clean. Don't bend or break anything or then you'll be cursing me.
On a 12 volt system like the stat I would probably even try a small spritz of WD-40 or carburetor cleaner on the contacts because that helps clean things too. Some people would disagree and recommend only using electrical contact cleaner.
The contacts of the temperature control on the bi-metal sound like they are working OK or it wouldn't be calling for purge/ignition when it goes below setpoint. FWIW. vic