You need to clarify. You should have a dual tstat.
1. On LP gas, when it senses the low temp has been met, it lowers the gas flame
2. On 120 electric, it has a contac point that opens and closes the current to the 120 element
IF it freezes on BOTH modes the tstat is defective. Taking the tstat valve apart and cleaning is never done regardless of what any manual you found and used. The Capillary sense metal tube does have a gas in it. Some of the tstats have 2 Capillary tubes, one for LP and one for 120. AND some models actually had 2 separate tstats. One for LP and one for 120, but they operated the same in bypassing in gas mode.
Have you checked to see if anybody has a replacement tstat? Doug
