E311 on a Samsung EHS TDM Plus: Error on temperature sensor of double layer pipe/liquid pipe (sub heat exchanger) (Short or Open)
Short answer
On a Samsung heat pump, E311 means: Error on temperature sensor of double layer pipe/liquid pipe (sub heat exchanger) (Short or Open). The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Error on temperature sensor of double layer pipe/liquid pipe (sub heat exchanger) (Short or Open).
Part involved: Error on temperature sensor of double layer pipe/liquid pipe (sub heat exchanger) (Short or Open).
When it shows: Unit self-diagnosis: Error on temperature sensor of double layer pipe/liquid pipe (sub heat exchanger) (Short or Open).
Likely causes:
- Refrigerant-side temperature sensor open/short circuit, detached or mis-located; connector or PCB fault.
- Engineer checks per Samsung service manual: Check sensor connection status, sensor location and sensor resistance against the Samsung resistance table (103 or 204 type); replace sensor or 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 sensor connection status, sensor location and sensor resistance against the Samsung resistance table (103 or 204 type); replace sensor or 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).
Certification: Competent electrical worker (BS 7671).
What you might notice
Sources
- Samsung EHS TDM Plus Service Manual Code AC-07002A_0 (Feb 2017) ↗ · AC-07002A_0 · page p.66 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026