Originally Posted by glennjanie
Welcome to the Fourm, Jonny:
A down and dirty test would be to remove the thermostat and tie the wires together; if it continues to run, its the thermostat. I'm not too fond of electronic thermostats anyway, maybe I'm just too old but they can fail any time without notice.
wow!!! (it would be 'down and dirty' alright.
To tell someone who is not at all familiar with Tstat wiring to tie the wires together is very foolish. unless a person knows what wires are what model of stat, equipment it serves, etc, ,a T stat can be destroyed simply by "tieing" wires together.
Jonny; most T stats, if maintained (batterys)wil usually outlast the normal life of a furnace (18-24 years or so) Some Honeywell T 87's, and many, many other makes are still ok after 20 years or more of work. Most homeowners(not all) will always blame the T stat because of their limited knowledge in the workings of a heating unit.
As I suggested in my earlier post, give us some more info on your problem.
Note; some Tstats use a red wire for incoming low voltage juice.Generally a white wire is your burner,green is to activate the fan.By jumping the red to the white normally will activate the burner, but you have to be certain of what your actually working with, especially if none of the wires are color coded.
It's best to let us know what your make,
, model # is,etc. ok?