E202 on a Samsung heat pump: CONTROL KIT / Outdoor UNIT Communication Error
Short answer
On a Samsung heat pump, E202 means: CONTROL KIT / Outdoor UNIT Communication Error. 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: CONTROL KIT / Outdoor UNIT Communication Error.
Part involved: Hydro unit/control kit and outdoor PCB communication.
When it shows: Unit self-diagnosis: CONTROL KIT / Outdoor UNIT Communication Error.
Likely causes:
- Communication/addressing fault between hydro unit (control kit) and outdoor unit, or between outdoor PCBs: wiring fault, loose connector, incorrect setting, electrical interference or PCB failure.
- Engineer checks per Samsung service manual: Check communication cable between hydro unit/control kit and outdoor unit; check PCB response LED and measure communication waveform (square wave approx. +/-0.7 V); replace PCB if required.
On the EHS Mono R32 (AE***RXYD*G)
The manual says: CONTROL KIT/OUTDOOR UNIT communication error (3 min).
Part involved: Hydro unit/control kit and outdoor PCB communication.
When it shows: Unit self-diagnosis: CONTROL KIT/OUTDOOR UNIT communication error (3 min).
Likely causes:
- Communication/addressing fault between hydro unit (control kit) and outdoor unit, or between outdoor PCBs: wiring fault, loose connector, incorrect setting, electrical interference or PCB failure.
- Engineer checks per Samsung service manual: Check communication cable between hydro unit/control kit and outdoor unit; check PCB response LED and measure communication waveform (square wave approx. +/-0.7 V); replace PCB if required.
On the EHS Split Generation 4 (AEX/AEN, 2014)
The manual says: Abnormal state, no communication between Indoor and Outdoor Main PCB.
Part involved: Hydro unit/control kit and outdoor PCB communication.
When it shows: Unit self-diagnosis: Abnormal state, no communication between Indoor and Outdoor Main PCB.
Likely causes:
- Communication/addressing fault between hydro unit (control kit) and outdoor unit, or between outdoor PCBs: wiring fault, loose connector, incorrect setting, electrical interference or PCB failure.
- Engineer checks per Samsung service manual: Check communication cable between hydro unit/control kit and outdoor unit; check PCB response LED and measure communication waveform (square wave approx. +/-0.7 V); replace PCB if required.
On the EHS Split R32 (AE***RXED*G)
The manual says: Hydro Unit / Outdoor Unit communication error(3 min).
Part involved: Hydro unit/control kit and outdoor PCB communication.
When it shows: Unit self-diagnosis: Hydro Unit / Outdoor Unit communication error(3 min).
Likely causes:
- Communication/addressing fault between hydro unit (control kit) and outdoor unit, or between outdoor PCBs: wiring fault, loose connector, incorrect setting, electrical interference or PCB failure.
- Engineer checks per Samsung service manual: Check communication cable between hydro unit/control kit and outdoor unit; check PCB response LED and measure communication waveform (square wave approx. +/-0.7 V); replace PCB if required.
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; then contact your installer or Samsung service; Samsung manuals do not describe a homeowner reset for this code.
What the engineer will check
- Check communication cable between hydro unit/control kit and outdoor unit; check PCB response LED and measure communication waveform (square wave approx. +/-0.7 V); replace PCB if required. Any work inside casings, on PCBs, wiring, sensors, pumps, valves or refrigerant is engineer-only.
Who to ask for: Heat pump engineer (Samsung-trained, controls/electrical).
Certification: Competent electrical worker (BS 7671) for work on live equipment.
What you might notice
What owners and engineers report
8 owner and engineer reports mention this.
- No heating on the EHS Mono R32 (AE***RXYD*G): 6 reports
- No hot water on the EHS Mono R32 (AE***RXYD*G): 1 report
- Heat pump will not start on the EHS Mono R32 (AE***RXYD*G): 1 report
Sources
- EHS R290 Mono Outdoor Unit Installation Manual AE***CXYD** (EU) DB68-12496A-03 ↗ · DB68-12496A-03 · page p.24 · Reviewed 23 September 2026
- EHS R-32 Mono Outdoor Unit Installation Manual (EU) DB68-08408A-07 ↗ · DB68-08408A-07 · page p.43 · Reviewed 23 September 2026
- Samsung Eco Heating System Service Manual - Outdoor Unit AEX060-160ED*HA / Hydro Unit AEN080/160YD*HA (file RC160MHXGA_SM_E_34513A(1)) ↗ · 34513A(1) · page ManualsLib viewer p.52 (printed p.51) · Reviewed 23 September 2026
- EHS R-32 Split Outdoor Unit Installation Manual (EU) DB68-08407A-06 ↗ · DB68-08407A-06 · page p.50 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026