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View Full Version : Furance won't turn off


doyou4x4
Jan 3, 2008, 04:00 PM
Have a chronotherm 3 thermostat, Lennox ECB19 12.5p furnace and a Lennox HP19-651-6d heat pump. The heat pump stopped working and then the furnace won't turn off, fan runs on high, I pushed the reset button on the heat pump where the blue wire is attached and now the heat pump works fine. But the furnace still won't stop running I have to turn it off at the braker in the house. I got a new thermostat and that didn't fix the problem and then I replaced a relay switch in the furnace and that didn't fix it. Then I replaced the three heat relays and that didn't fix it. Now I'm confused as to what it could be any help would be apperacated. Note when I remove the white wire at ether the furnace or heat pump the fan will turn off when the heat pump turns off when normaly the fan will run for 2min then turn off.

T-Top
Jan 3, 2008, 07:45 PM
It's the fan relay stuck or your R and G thermostat wires are grounded to each other. Turn power off to your fan coil unit remove the G Circuit from the thermostat wire to the unit. Turn the power back on if the blower runs it's a stuck blower relay or wired wrong.