E507 on a Samsung heat pump: Comp Down due to high pressure or High Pressure Switch Open
Short answer
On a Samsung heat pump, E507 means: Comp Down due to high pressure or High Pressure Switch 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: Comp Down due to high pressure or High Pressure Switch Open.
Part involved: Compressor / refrigerant cycle protection.
When it shows: Unit self-diagnosis: Comp Down due to high pressure or High Pressure Switch Open.
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: Check high pressure switch and refrigerant circuit (blockage, overcharge, water flow).
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 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
- Check high pressure switch and refrigerant circuit (blockage, overcharge, water flow). 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; R290 (A3 flammable refrigerant) competence.
Certification: F-gas certification (UK F-gas Regulation; e.g. City & Guilds 2079 Cat I); R290/flammable refrigerant handling training (e.g. hydrocarbon refrigerant course).
What you might notice
Sources
- EHS R290 Mono Outdoor Unit Installation Manual AE***CXYD** (EU) DB68-12496A-03 ↗ · DB68-12496A-03 · page p.24 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026