Some thermostats are single pole, double throw, i.e., when cold (room temp), there will be continuity between two terminals- common & normally closed. When the thermostat reaches a set temperature, then there should be continuity between common & normally open. Typically, there will be two thermostats in series with with valve coils and igniter, temperature cycling (either normal or low temp setting) and a hi limit thermostat. Do you have a wiring diagram? |