The thermocouple tells the gas valve to supply gas to the burners. If the thermocouple is bad then the furnace will not work or the pilot will not stay lit. A properly working one will have a reading of at least 12 milliamps.
Bad thermo,replace. The thermo senses that the pilot is lit and opens gas valve,also could be bad or blocked gas valve.
No, it will just keep your furnace from turning on. At least that's the problem I'm having right now with the bad thermopile in my floor furnace.
Not likely, could be hi temp limit switch or bad air flow.
Blown fuses or bad elements.
Bad ignition module.
bad thermal coupling
If the software everything is ok then you have check the thermo paste which is between the radiator and the cpu. You might have a bad thermo contact over there. so what em i looking for when i check the thermo paste
When a typical residential furnace or gas package unit "high limit switch" is found to be bad it is replaced with a new one-not repaired.
Thermocouple is probably bad and needs replacing.
Viscuous coupling in the transfer case could be going bad.
Thermosetting plastics such as polyoxybenzylmethylenglycolanhydride better know as 'Bakelite' and some others.
Squuze the upper hose when thermo is closed. You will feel water circulating when thermostat is open. If it is circulating you are ok. Not much can go wrong internally, they either leak or the bearings go out which make noise but you can see or hear that..