Heat pumps · Error codes · Cool Energy
Er01Cool Energy
Er01 on a Cool Energy heat pump: PCB / Wire Controller Fault
Short answer
On a Cool Energy heat pump, Er01 means: PCB / Wire Controller Fault. 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 · 2 sources
What it means
On the Inverter range CE-iH (R410A, c.2020)
The manual says: PCB / Wire Controller Fault.
On the Pro Range CE-H (fixed-speed)
The manual says: Phase Failure.
Likely causes:
- Absent phase, phase rotation or voltage imbalance among the 3 phases.
- Controller or PC board faulty (phase rotation protection damaged).
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
On the Inverter range CE-iH (R410A, c.2020)
- Power-cycle / re-initialise parameters as instructed by the manufacturer.
- Check controller firmware/parameters.
- Replace controller/PCB if the fault persists.
Who to ask for: heat pump controls.
Certification: Electrical competence.
On the Pro Range CE-H (fixed-speed)
- Check incoming phase rotation with a phase rotation meter.
- Test for absent phase and cable connections.
- Test for voltage imbalance.
- Replace PC board and/or controller.
- Check supply voltage, phase presence/rotation and balance.
- Check cabling, terminals and MCB/RCBO sizing.
- Check inverter drive/PFC board.
Who to ask for: heat pump electrical.
Certification: Electrical competence (Part P / qualified electrician).
What you might notice
Sources
- Cool Energy Inverter Monoblock Series Heat Pump Water Heaters - Installation and Users Guide Version 5 ↗ · Version 5 · page 22 · Reviewed 23 September 2026
- 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