9
Rheem
High Limit or Auxiliary Limit Lockout
Status LED flashes 9 times; furnace may run blower continuously without heat
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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
Repeated overheating events, Blocked filter or ductwork, Failed blower motor or capacitor, Faulty limit switch circuit
How to Fix / Troubleshooting
Safety first: Turn off power before accessing blower or wiring.
- Replace air filter: Install a new filter of the correct size and MERV rating. Avoid overly restrictive filters.
- Inspect blower wheel: Remove blower compartment panel and visually inspect the blower wheel for heavy dust buildup. Clean if necessary.
- Check blower motor start: With power restored, call for heat and verify the blower starts on time and reaches full speed. If it hums or starts slowly, the run capacitor or motor may be failing.
- Reset lockout: Turn power off for 30–60 seconds to reset the control. If the code returns after a few cycles, have the limit circuit and duct system evaluated.
Persistent limit lockouts can damage the heat exchanger; do not ignore this condition.
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Repair Difficulty
Hard
4/5
Required Part
Blower Motor Run Capacitor
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