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Rinnai · Tankless water heater

61 Combustion fan motor fault

High severity Non-SENSEIRH180 hybridSENSEI RX/CXSENSEI

What the control is telling you

The combustion fan motor is not operating correctly, due to wiring, a seized or obstructed blower, open windings, incorrect supply voltage or a control board fault.

Applies to: SENSEI Series, SENSEI RX/CX Series, Non-SENSEI Series

Likely causes

  • Loose, broken or damaged fan motor wiring
  • Blower wheel binding or debris in the fan housing
  • Check valve behind the fan stuck closed (SENSEI / SENSEI RX/CX)
  • Open fan motor windings
  • Incorrect fan supply voltage from the PC board
  • Faulty PC board

Test and repair steps

  1. Warning: Turn off power and gas before servicing the fan. Never plug or unplug the motor with power applied; doing so can damage the fan motor and other parts.
  2. Inspect the harness from the fan motor to the PC board for loose, broken or damaged connections.
  3. With power and gas off, remove the fan motor and confirm the blower wheel spins freely.
  4. Check the fan housing for debris that could stop the wheel from turning.
  5. SENSEI / SENSEI RX/CX Make sure the check valve behind the fan motor is not stuck closed.
  6. Measure fan motor winding resistance against the Technical Data Sheet (behind the front cover) or service manual; replace the motor if windings are open.
  7. SENSEI RX/CX With the unit running, measure at CN7: red #1–black #2 = 7-48 VDC; white #4–black #2 = 2-14 VDC; yellow #3–black #2 = 11-13 VDC (see Electric Circuit Table/wiring diagram).
  8. If windings and voltage are within spec and the fan turns freely, replace the PC board.

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Source: Rinnai Troubleshooting TWH Diagnostic Codes (100000652), p.52. Summarized in our own words; check the original manual for your model.

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For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.