Heat pumps · Error codes · Cool Energy
Er35Cool Energy · Pro Range CE-H (fixed-speed)
Er35 on a Cool Energy Pro Range CE-H: Compressor over current protection
Short answer
On a Cool Energy heat pump, Er35 means: Compressor over current protection. 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: Compressor over current protection.
Likely causes:
- Compressor over current.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
What you can check
- Read and note the code shown on the controller display, then contact your installer or service engineer.
- Check the heat pump's breaker/isolator at the consumer unit is switched on (do not repeatedly reset if it trips).
What the engineer will check
- Check incoming voltage.
- Check if compressor is overloaded.
- Check thermal relay and replace if damaged.
- Check compressor windings and wiring/phase sequence.
- Check inverter drive parameters match compressor model.
- Check operating envelope (flow, pressures, load).
Who to ask for: refrigeration / F-gas heat pump engineer.
Certification: F-gas certification; electrical competence.
What you might notice
Sources
- Cool Energy Pro Monoblock Series Heat Pump Water Heaters - Installation and Users Guide Version 5 ↗ · Version 5 · page 25 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026