E601 on a Samsung heat pump: Communication error between the Hydro Unit and AI Home
Short answer
On a Samsung heat pump, E601 means: Communication error between the Hydro Unit and AI Home. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause. The wording differs by model range — each is shown below.
Reviewed 23 September 2026 · 4 sources
What it means
On the EHS Mono R290 (AE***CXYD*K and pump-integrated AE***CXYB*K)
The manual says: Communication error between the Hydro Unit and AI Home.
Part involved: Wired remote controller / AI Home controller.
When it shows: Unit self-diagnosis: Communication error between the Hydro Unit and AI Home.
Likely causes:
- Wired remote controller communication, setting, sensor or memory fault; controller wiring (F3/F4) fault.
- Engineer checks per Samsung service manual: Follow Samsung service manual troubleshooting for this code.
On the EHS Mono R32 (AE***RXYD*G)
The manual says: Communication error between the CONTROL KIT and wired remote controller.
Part involved: Wired remote controller / AI Home controller.
When it shows: Unit self-diagnosis: Communication error between the CONTROL KIT and wired remote controller.
Likely causes:
- Wired remote controller communication, setting, sensor or memory fault; controller wiring (F3/F4) fault.
- Engineer checks per Samsung service manual: Follow Samsung service manual troubleshooting for this code.
On the EHS Mono (RC***MHX*A, R410A)
The manual says: Communication error between the CONTROL KIT and.
Part involved: Wired remote controller / AI Home controller.
When it shows: Unit self-diagnosis: Communication error between the CONTROL KIT and.
Likely causes:
- Wired remote controller communication, setting, sensor or memory fault; controller wiring (F3/F4) fault.
- Engineer checks per Samsung service manual: Follow Samsung service manual troubleshooting for this code.
On the EHS Split R32 (AE***RXED*G)
The manual says: Communication error between the Hydro Unit and wired remote controller.
Part involved: Wired remote controller / AI Home controller.
When it shows: Unit self-diagnosis: Communication error between the Hydro Unit and wired remote controller.
Likely causes:
- Wired remote controller communication, setting, sensor or memory fault; controller wiring (F3/F4) fault.
- Engineer checks per Samsung service manual: Follow Samsung service manual troubleshooting for this code.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: unknown.
Manual reset: unknown.
What you can check
- Note the full error code shown on the controller; check the heat pump breaker/isolator in the consumer unit is ON; check thermostat/timer and controller operating-mode settings; then contact your installer or Samsung service; Samsung manuals do not describe a homeowner reset for this code.
What the engineer will check
- Follow Samsung service manual troubleshooting for this code. Any work inside casings, on PCBs, wiring, sensors, pumps, valves or refrigerant is engineer-only.
Who to ask for: Heat pump engineer (controls).
Certification: Competent electrical worker (BS 7671).
What you might notice
What owners and engineers report
9 owner and engineer reports mention this.
- Controller / thermostat problem on the EHS Mono R290 (AE***CXYD*K and pump-integrated AE***CXYB*K): 2 reports
- Controller / thermostat problem on the EHS Mono R32 (AE***RXYD*G): 7 reports
Sources
- Air to Water Heat Pump User manual AE200DN**** / AE160DN**** / MIM-E03FN (2024 ClimateHub / control kit) DB68-12922A-05 ↗ · DB68-12922A-05 · page p.57 · Reviewed 23 September 2026
- EHS R-32 Mono Outdoor Unit Installation Manual (EU) DB68-08408A-07 ↗ · DB68-08408A-07 · page p.44 · Reviewed 23 September 2026
- Air to Water Heat Pump Mono Outdoor Unit installation manual RC***MHXGA / RC***MHXEA DB98-34411A(2) ↗ · DB98-34411A(2) · page p.37 · Reviewed 23 September 2026
- EHS R-32 Split Outdoor Unit Installation Manual (EU) DB68-08407A-06 ↗ · DB68-08407A-06 · page p.51 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026