After making sure my t stat was not the problem I replaced my sequencer... the problem was that my furnace would not quit making heat... worked for a few weeks and then the same thing happened but now I think one of the thermal fuses blew... what makes the sequencer go bad?

What makes the sequencer go bad?

Thermal overload or using a sequencer that has a lower amp/watt rate on a circuit that draws to much current for the device to handle.

Loose wiring connections causing thermal stress of the device (heat sequencer)

A poorly made sequencer from the factory (especially if made in China).

A defective heater that is past its useful life. Usually that is indicated by an element that is sagging sometimes allowing one element to touch another element in the furnace causing a short circuit or other thermal event.


In all cases an Amprobe or other such testing device should be used especially when working on electric furnaces so each circuit (heater) can be tested and compared to its label rating. This insures that the heater is working in its proper capacity and that other components (sequencers, relays) are not overtaxed while doing there jobs.

the problem was that my furnace would not quit making heat

Usually if a furnace does not stop making heat a wiring problem exists that keeps the heater locked in the ON position all the time.I suggest that is you replace the defective parts and recheck your wiring to be sure the furnace turns off as it is designed to do when the temperature as set by the thermostat is satisfied.