[HayZee518]

the hot surface ignitor operates on 120 volts and the thermostat is 24 volt - so there isn't a problem between the stat and the ignitor. the terminations for the ignitor needs to be tight, a loose condition will change the resistance of the unit. another new fangled safety feature. in this case the main gas valve is current sensitive and operates off the ignitor's resistance. the old formula for current is amps equals volts divided by resistance. 120 / 60 ohms = 2 amps. 120 / 40 ohms = 3 amps. 120 / 20 ohms = 6 amps. so if the main valve is seeing other then what current is meant for it - it will not open.