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Rheem / Ruud 802V / 80MDV Furnace Codes
The (-) in the model number stands for the brand prefix (Rheem or Ruud). Other Rheem two-stage furnaces use different code lists; check the installation instructions for your model.
| Code | Meaning | What to check |
|---|---|---|
| d1 | No model data (critical; furnace won't run in any mode). | Memory card missing or disconnected from connector P6 on the control. Cycle power after reinstalling it. |
| d4 | No valid model data on the memory card (furnace still runs using model data in the control). | Replace with the original or correct memory card for this furnace. |
| d6 | Horsepower conflict on the memory card. | Wrong replacement blower motor, or the wrong memory card or control was installed. |
| 10 | One-hour lockout. Alternates with the code that caused it. | How to fix → |
| 11 | Failed ignition. After four in a row the control enters one-hour lockout. | Flame rod, gas valve off, igniter, control, or flame not carrying from the first burner (check manifold pressure). How to fix → |
| 12 | Low flame sense (furnace keeps running). | How to fix → |
| 13 | Flame lost after it was established. | Flame sensor, sensor mounting or ground, unstable flame, burner compartment seals. How to fix → |
| 14 | Flame present with the gas valve off. | 24 V miswired to the gas valve, valve stuck open, or a faulty control. |
| 22 | Main limit open. | Airflow first: blower, filter, ductwork and static pressure, then firing rate. Open more than 150 seconds brings code 61. How to fix → |
| 23 | HALC open. | No continuity between pins 3 and 5 of connector P1; repair the jumper. |
| 26 | Line and neutral reversed, or poor ground. | Check polarity at the furnace and at the disconnect or breaker, and the cabinet ground. |
| 30 | Open fuse. | 24 V short to common or ground. Fix the short, then replace the fuse. How to fix → |
| 33 | Over-temperature (rollout) switch open, manual reset (MRLC). | Venting, pressure switch bypassed, wiring, unstable flame, burner and door seals, damaged heat exchanger. How to fix → |
| 44 | Low pressure switch closed with the inducer off. | Welded or bypassed switch, wiring, or abnormal vent draft. How to fix → |
| 45 | Low pressure switch open with the inducer on high speed. | Blocked or overlong vent, inducer, control relay, wiring, pressure hoses, wind, switch. How to fix → |
| 46 | Low pressure switch open with the inducer on low speed. | Same as 45, plus a missing high altitude kit. How to fix → |
| 55 | High pressure switch closed with the inducer off. | Welded or bypassed switch, wiring, or abnormal vent draft. How to fix → |
| 57 | High pressure switch open with the inducer on high speed. The furnace may continue on low fire. | Vent, inducer, control relay, high altitude kit, wiring, hoses, wind, switch. How to fix → |
| 58 | Water circuit open (gas heat stops; cooling still works). | No continuity between pins 1 and 2 of connector P4; repair the jumper or connector. |
| 60 | Blower fault, blower can still run (non-critical). | Blower at its speed or torque limit: static pressure too high. How to fix → |
| 61 | Blower fault, motor can't run (critical). | Motor thermal trip, power factor correction choke, memory card, wiring, loose blower wheel, failed motor. |
| 66 | Blower cutback (operating indicator, not a true fault). | Static pressure too high for the airflow the blower is asked for. How to fix → |
| 68 | No blower communications. | Motor wiring and connections, line voltage to the motor and choke, memory card, failed motor. |
| 93 | Internal control fault. | Voltage on the gas valve circuit when there shouldn't be (miswiring), or a failed control. |
| 99 | Fault history reset (notification only). |
How to read the codes
- Normal operation codes are not faults: 0 standby; h or H low or high gas heat; c or C low or high cooling; hP or HP low or high heat-pump heat; F continuous fan; dF defrost (dual fuel, low-stage gas heat); cd or Cd cooling with dehumidification.
- Check the display's orientation first. Rheem notes the codes can read upside down; if a code isn't on these lists, the display may be inverted.
- During a one-hour lockout, 10 alternates with the fault that caused it (11, 13, 14, 61 or 93). Four failed ignitions or five flame losses in a row cause the one-hour lockout.
Codes point to a circuit, not a part. Test before replacing anything, and never jumper a limit, rollout or pressure switch to keep a furnace running. Gas and line-voltage work is for trained technicians.
Source: Rheem Installation Instructions, (-)802V / (-)(-)80MDV two-stage communicating gas furnaces, 92-24161-148-04, Tables 12 and 13 (pp. 64-73). The "meaning" column follows the manufacturer's wording; "what to check" is our field summary. Always go by the label on the furnace you're working on.
Related
- How to read furnace LED flash codes
- Furnace pressure switch troubleshooting
- Flame sensor microamps and cleaning
Other brands
- Lennox Merit ML180UH (80% single-stage)
- Carrier 58CVA / 58CVX (80% variable-speed two-stage)
- Rheem / Ruud R96V / 96MDV (96% two-stage communicating)
- Goodman / Amana GR9S80 / GD9S80 (80% single-stage)
- Trane / American Standard S9X1 / S9X2 / S9B1 (96% condensing)
- Lennox SL280UHV (80% two-stage variable speed)
- Goodman / Amana / Daikin GM9S96 / GC9S96 / GM9S92 (96% and 92% condensing, single-stage)
- Carrier 59TP6C two-stage condensing with InteliSense (Performance series)
- Lennox G60DF / G60DFV (older two-stage SureLight boards 18M3401, 46M9901, 18M9901, 49M5901)
- Lennox G60UH / G60UHV (SureLight boards 100869 and 100870)
- Rheem / Ruud R801T Ultra Low NOx (14 ng/J) single-stage upflow/horizontal, constant-torque blower
- Trane / American Standard S8B1 / S8X1 / S8X2 (80% single-stage and two-stage)
- Goodman / Amana GMVC96 / GCVC96 (96% two-stage variable-speed, *MVC96*BA and *CVC96*BA)
- Goodman / Amana GMVS96 / AMVS96 U-revision (96% variable-speed with analog pressure sensor, model numbers GMVS96*U and AMVS96*U)
- Goodman / Amana GMVM96 / GCVM96 / AMVM96 / ACVM96 (96% modulating, model numbers *MVM96 and *CVM96)
- Rheem / Ruud R801T / 80MSX (80% single-stage, constant-torque blower; model numbers (-)801T and (-)(-)80MSX)
- Rheem / Ruud 802P / 80MDP (80% two-stage, model numbers (-)802P and (-)(-)80MDP)
- Rheem / Ruud 802T / 80MDT (80% two-stage with constant-torque blower, model numbers (-)802T and (-)(-)80MDT)
- Rheem / Ruud 801S / 801P / 80MSS / 80MSP (80% single-stage, model numbers (-)801S, (-)801P, (-)(-)80MSS and (-)(-)80MSP)
- Carrier 58STA / 58STX (80% single-stage, 4-way multipoise)
- Carrier 58SB0A / 58SB1A (single-stage, non-condensing)
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