Day and Night furnace model 80CN from 1964. Worked fine and only used here in So Calif for cold nights. Now burners come on and off and don't stay on. Cleaned the sensor near the pilot, but think that the problem is in the gas valve. Rarely use this furnace so would prefer to fix it despite its age and tax rebates. Read other result but want to know if anyone has anything to add, even if repetitive. Rarely gets below 45 F here.

Main limit will turn the burners off make sure your filters are clean. If you turn the blower to on at the thermostat and make it call for heat will the blower run and heat the house?