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View Full Version : Heat on central unit will shut down


dhyatt
Dec 21, 2008, 12:29 PM
Heating syste on central air unit will not shut off t-stat has been replaced. Disconnected power for unit and check relays in system have one relay that is operates fan and another that that routes power to fan really and to heater coil both had continuity until I disconnect power wire coming to fan relay on contact 1 and that really now is good across all contacts. The main relay showed continuity through contact positions starte to disconnect the wiring from really and upper body of relay came off in hand. Think tis is the problem any advice would be apperciated.

Thanks
Dhyatt

Larryg300
Dec 21, 2008, 01:31 PM
On most furnaces if one of the safety switch (i.e.inducer blower pressure switch, roll back switch, limit switch or even the circuit board fuse) is tripped (opens if its normally closed). The indoor fan will run continuously.

MarkwithaK
Dec 21, 2008, 01:46 PM
Well if your relay came apart then I would start there lol.

KC13
Dec 21, 2008, 02:00 PM
Sounds like a stack-type sequencer that came apart... I wouldn't feel too bad about breaking it, if it came apart that easily it was likely your problem to begin with.