Rheem Error Codes
Every Rheem error code we have catalogued, with what it means on site — 11 codes in total. In R-Pro, tap any code to get the meaning, likely causes and inspection steps, even with no signal in the plant room.
Common Rheem codes
- 21 — Low pressure control open (low charge / frozen coil / dirty filter)
- 29 — High pressure (dirty outdoor coil / fan off / overcharge)
- 27 — Low or no line voltage
- 28 — High line voltage
- 1 Flash — Low pressure switch open
- 2 Flash — High pressure switch open
- 3 Flash — Defrost sensor failure
- 4 Flash — Outdoor thermistor error
| Code | What it means |
|---|---|
| 21 | Low pressure control open (low charge / frozen coil / dirty filter) |
| 29 | High pressure (dirty outdoor coil / fan off / overcharge) |
| 27 | Low or no line voltage |
| 28 | High line voltage |
| 1 Flash | Low pressure switch open |
| 2 Flash | High pressure switch open |
| 3 Flash | Defrost sensor failure |
| 4 Flash | Outdoor thermistor error |
| 5 Flash | Overcurrent protection |
| 6 Flash | Compressor overcurrent protection |
| 7 Flash | PCB communication error |
Official Rheem source / manual ↗
Frequently asked
What does Rheem error code 21 mean?
Rheem error code 21 means: Low pressure control open (low charge / frozen coil / dirty filter). In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 29 mean?
Rheem error code 29 means: High pressure (dirty outdoor coil / fan off / overcharge). In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 27 mean?
Rheem error code 27 means: Low or no line voltage. In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 28 mean?
Rheem error code 28 means: High line voltage. In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 1 Flash mean?
Rheem error code 1 Flash means: Low pressure switch open. In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 2 Flash mean?
Rheem error code 2 Flash means: High pressure switch open. In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 3 Flash mean?
Rheem error code 3 Flash means: Defrost sensor failure. In R-Pro you also get the likely causes and the inspection steps — offline.
What does Rheem error code 4 Flash mean?
Rheem error code 4 Flash means: Outdoor thermistor error. In R-Pro you also get the likely causes and the inspection steps — offline.
Look up any error code — offline — in R-Pro.
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