Gas furnace- blower turns on manually, but not in auto mode

Old 02-07-14, 11:43 PM
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Gas furnace- blower turns on manually, but not in auto mode

We have an old gas furnace in a detached garage that we typically keep at about 53 degrees. If we spend any time in the garage we'll raise the temperature up a bit- say 57. Well we did that today and the furnace wouldn't shut off when it reached the setpoint. It kept running until it was uncomfortably warm, when I finally just killed the power to the furnace. I waited awhile and then turned the power back on. Now, if I turn the fan to "on" via the tstat, the fan kicks on right away. But if I leave it on "auto" and the temperature falls below setpoint, I can hear the tstat click like it's trying to send a signal, but nothing happens, so there's no fan and obviously no heat.

Any suggestions on what to do to get this thing up and running again? It's an old (from 1986) Bryant furnace that had a new control board put in (while it was under a home warranty) about a year ago.

Any help would be greatly appreciated.
Old 02-08-14, 06:12 PM
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Welcome to the forums.

To see if it's a thermostat problem..... try placing a jumper wire across the R and W terminals either at the thermostat or at the furnace. You can just touch the jumper to the don't have to put under the screw.

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