E442 on a Samsung EHS TDM Plus: Refrigerant charging restriction in heating mode when air temperature is over 15 °C
Short answer
On a Samsung heat pump, E442 means: Refrigerant charging restriction in heating mode when air temperature is over 15 °C. The heat pump keeps running with some functions stopped.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Refrigerant charging restriction in heating mode when air temperature is over 15 °C.
Part involved: Compressor / refrigerant cycle protection.
When it shows: Unit self-diagnosis: Refrigerant charging restriction in heating mode when air temperature is over 15 °C.
Likely causes:
- Compressor stopped by refrigerant-cycle protection (pressure, discharge temperature, overload or compression ratio): e.g. refrigerant under/overcharge, blockage, poor water flow or airflow, sensor fault.
- Engineer checks per Samsung service manual: Refrigerant charging function restricted above 15 °C outdoor temperature; perform charging per manual.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Warning |
The heat pump keeps running with some functions stopped.
Resetting itself: yes - clears when conditions return within range.
Manual reset: not required.
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 the outdoor unit is not blocked by leaves, debris or snow and air can flow freely; check the heating system pressure gauge reading (typically 1-2 bar when cold; do not top up unless you have been shown how); then contact your installer or Samsung service; Samsung manuals do not describe a homeowner reset for this code.
What the engineer will check
- Refrigerant charging function restricted above 15 °C outdoor temperature; perform charging per manual. Any work inside casings, on PCBs, wiring, sensors, pumps, valves or refrigerant is engineer-only.
Who to ask for: F-gas certified refrigeration/heat pump engineer.
Certification: F-gas certification (UK F-gas Regulation; e.g. City & Guilds 2079 Cat I).
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