Posted: 12/7/2016 6:32:43 AM EDT
| My furnace blower motor keep running yesterday morning The Until I shut the thermostat off for a couple minutes.Then I turned the thermostat back on and everything worked fine again.Then this morning It was doing the same thing but I turned the thermostat off this morning and then back on and the blower kept running. the thermostat is a Honeywell RTH7600 series.The furnace is a lennox serial # 5905C17470 model # G40UH-36A-070-07.The fan just shut off while I was typing this. Thanks to all that help. |
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Blower fan or inducer fan?
It should be blinking a code on the board if there is a fault and there should be a fault code printout inside the door. Since blower on/off is a time delay built into the board there is no mechanical fan switch. Issues could be riding on limit and a sticky limit [because it's been doing it for awhile], sticking pressure switch, bad board relay, etc but need to know if the blower is running or the inducer is. Could also just be a dirty flame sensor, three tries for heat can cause some furnaces to lock out and blower come on until depowered on call for heat has been interuppted [by turning down the T stat for a few seconds below call point. |
| The led lights flashing green when the furnace is running are fast flashes and my owners manual says normal operation-when heating demand initated at thermostat. After the furnace comes on with the fan and does its cycle and shuts off the fan quits running and the manual says with both led flashing slow and green normal operation. So I don't know what to do. |
| You'll need to see what code it's flashing when it's not running correctly. Do NOT touch the T Stat or cut power, you'll lose the codes, you need to go to the furnace and read codes before opening the blower door because opening it will cut power due to the door safety switch opening up. Oncwe you have the codes, you'll know where proper operation is being interupted. [unless the board is at fault because most times, the board can't check itself] |