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Rheem · Furnace troubleshooting

No heat - inducer (IDM) does not start

What is going on

POWER LED on, thermostat calling, but the induced draft motor never starts.

Likely causes

  • No 24 V on W
  • Thermostat not in heat / dead batteries / wiring
  • Lockout or fault code present
  • No line voltage to IDM, bad wiring, bad capacitor

Check in this order

  1. Set FAN to AUTO and call for heat with the setpoint more than 10°F above room temperature.
  2. Check for 24 V from W to C at the IFC; if none, check thermostat mode, batteries, wires and connections.
  3. Check the STATUS LED if blinking, follow the blink code; if steady on, check the pressure switch is not stuck closed (contacts, short, water) then the IFC.
  4. If W is present and no code check line voltage at the IDM, the wiring between IDM and IFC, line voltage on the IDM pins of the IFC connector, and the IDM capacitor (90+ only).

Applies to: Rheem (-)GRC/(-)GTC and 90RJ/90TJ 90 Plus condensing gas furnaces

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Source: Rheem (-)GRC/(-)GTC Installation Instructions 92-24161-88-00, Figure 56 IFC Troubleshooting Guide, p.54 (printed); Rheem 90RJ/90TJ Installation Instructions 92-24161-32-08, Figure 53, p.54. Written in our own words; check the manual for your exact model.

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.