US Stove Stuck Combustion Blower Relay or Control Logic Fault

Combustion blower runs continuously even when furnace is off and cool.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Control board relay contacts welded closed, Miswired blower circuit, Shorted blower control transistor, Incorrect wiring after repair

How to Fix / Troubleshooting

Safety first: Unplug the furnace to stop the blower before working on it.

Steps:

  • 1. Verify settings: Ensure the furnace is not in a special test or cleaning mode that keeps the blower running.
  • 2. Inspect wiring: Check that the combustion blower is wired to the correct terminals on the control board and not tied directly to line power.
  • 3. Control board relay: If wiring is correct, the blower relay on the control board may be stuck. Replace the control board.
  • 4. Temporary use: Do not attempt to bypass the board or hard-wire the blower; this can create unsafe conditions.
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Repair Difficulty

Hard 4/5

Required Part

Main Control Board
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