The burner is correct but the furnace overheats
After a circulating-blower motor replacement, a furnace reaches its high limit while the room thermostat continues calling. The burner input has been verified at the appliance’s specified condition, and the combustion checks do not point to excessive firing. The measured air-temperature rise is above the appliance’s permitted range. The replacement motor has the same nominal power as the old one, but the technician has not checked its rotation, speed connection or blower-wheel position against the equipment instructions. Several return grilles were also moved during recent renovations. The appliance remains out of normal service while these conditions are assessed. Current airflow and motor specifications are available to support the comparison.
1. What should be investigated before changing fuel or limit settings?
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Trace circulating airflow through the return, filter, blower and supply route. Verify the replacement motor’s complete application and assembly. Correct input with excessive temperature rise makes inadequate heat removal a relevant direction rather than a reason to weaken the limit.
2. What completes the repair?
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Correct the actual airflow or component condition, restore the specified assembly and verify temperature rise, operating sequence and protective response. Record the evidence and any unresolved restriction rather than accept one successful ignition or a warm supply grille as full proof.