RecPro Air Conditioner: “E8”
warning RV air conditioner error codes
What it means
The outdoor ambient temperature sensor is reading out of range or has failed.
Most likely causes
- Disconnected or damaged outdoor ambient sensor wiring most likely
- Failed outdoor ambient temperature sensor common
- Control board input fault less common
Safe checks you can do yourself
- With power off, inspect the outdoor sensor connector at the rooftop control box for corrosion or a loose pin.
- Look for moisture intrusion at the connector.
How to reset / clear E8
- Turn the unit off and remove power at the breaker for about a minute.
- Restore power; if the sensor connection is good the code should clear.
When to call a technician
If reseating the connector does not clear E8, have a technician test or replace the outdoor ambient sensor or control board.
Applies to
RecPro RP-AC3501 · RecPro RP-AC3800 · RecPro A3501 / A3800 / T3500 (ducted)
FAQ
What does RecPro Air Conditioner code "E8" mean?
The outdoor ambient temperature sensor is reading out of range or has failed.
How do I reset RecPro Air Conditioner E8?
Turn the unit off and remove power at the breaker for about a minute. Restore power; if the sensor connection is good the code should clear.
What is the most common cause of E8 on a RecPro Air Conditioner?
The most likely cause is disconnected or damaged outdoor ambient sensor wiring.
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Sources
- RP-AC3501 / RP-AC3800 Ducted Air-Conditioning System Owner's Manual — Outdoor temperature sensor fault E8 (RecPro)
Note: E8 appears in the ducted RP-AC3501/3800 code table; the same code applies to the equivalent Houghton-branded ducted units.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.