US Stove
Loss of Proof-of-Fire or Poor Combustion
Furnace lights but then goes out after a few minutes; repeats short cycling.
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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
Dirty burn pot restricting air, Weak combustion blower, Low limit switch not sensing heat, Poor quality or damp fuel
How to Fix / Troubleshooting
Safety first: Turn off and unplug the furnace. Allow it to cool before cleaning.
Steps:
- 1. Clean burn pot and firebox: Remove the burn pot and scrape all ash and clinkers. Ensure all air holes are open. Vacuum the firebox and ash traps with a metal ash vacuum.
- 2. Check combustion blower: Verify the blower starts promptly and runs strongly. Clean the blower wheel and exhaust passages.
- 3. Inspect low limit (proof-of-fire) switch: Ensure it is firmly mounted and wiring is intact. Replace if it fails to close when the furnace is hot.
- 4. Use proper fuel: Switch to high-quality, dry pellets or coal recommended by US Stove. Store fuel in a dry location.
- 5. Monitor operation: Restart the furnace and observe. If the flame remains weak or the unit still shuts down early, have a technician check draft and control settings.
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Repair Difficulty
Medium
3/5
Required Part
Burn Pot Assembly
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