10 FLASHES
Ruud
Communication Error / IFC Internal Fault
Status LED shows 10 flashes, furnace will not start, thermostat appears to call for heat but no response.
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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
Failed integrated furnace control board, Shorted low-voltage wiring, Incorrect thermostat wiring, Surge or brownout damage to control
How to Fix / Troubleshooting
Safety: Turn off power before working on low-voltage wiring or the control board.
Steps to check:
- Inspect thermostat wiring: At the furnace control board, verify R, W, Y, G, and C wires are correctly landed and not shorted together. Look for bare spots where wires may touch the cabinet.
- Check for shorts: Disconnect thermostat wires at the furnace and install a jumper between R and W at the board. If the furnace starts normally, the thermostat or thermostat cable may be faulty.
- Look for water damage: Inspect the control board for signs of water from a leaking humidifier, condensate line, or roof leak. Any corrosion or burn marks indicate board replacement is needed.
- Replace IFC if necessary: If wiring is correct and the code persists, the integrated furnace control board is likely defective and should be replaced with the correct Ruud OEM board.
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Repair Difficulty
Hard
4/5
Required Part
Integrated Furnace Control Board
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