Heat pumps · Error codes · Cool Energy
EFCool Energy · EcoStore all-in-one exhaust-air DHW heat pump
EF on a Cool Energy EcoStore all-in-one exhaust-air DHW heat pump: Clock chip error
Short answer
On a Cool Energy heat pump, EF means: Clock chip error. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Clock chip error.
Likely causes:
- Chip broken; unit can work without clock memory, clock must be reset at power-on.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
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
- 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.
What you might notice
Sources
- Cool Energy EcoStore Heat Pump Water Heater - manual Rev1 ↗ · Rev1 · page 24-26 (printed) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026