Carrier Blower-Induced Flame Disturbance or Voltage Drop

Furnace starts normally but shuts off when the blower comes on.

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.

Possible Causes

Cracked heat exchanger causing flame disturbance, loose electrical connections causing voltage sag when blower starts, incorrect blower speed

Safety first: Turn off power and gas. This symptom can indicate a serious safety issue.

Observe flame behavior: With a professional present, the flame should remain stable when the blower starts. If the flame flickers or is pulled away from the burner, a cracked heat exchanger is possible.
Check electrical connections: Tighten all wire nuts and screw terminals on the control board and blower motor.

Because of the risk of carbon monoxide from a cracked heat exchanger, this condition should be evaluated by a licensed HVAC technician immediately.

Professional Required 5/5

Heat Exchanger

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