Heat pumps · Error codes · Cool Energy
E005Cool Energy · EcoSyn wall-hung exhaust-air DHW heat pump
E005 on a Cool Energy EcoSyn wall-hung exhaust-air DHW heat pump: Overheating (temperature >85C, electronic regulator failure)
Short answer
On a Cool Energy heat pump, E005 means: Overheating (temperature >85C, electronic regulator failure). The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Overheating (temperature >85C, electronic regulator failure).
Is it safe?
Switch the heat pump off at its isolator and call an engineer.
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Read and note the code shown on the controller display, then contact your installer or service engineer.
- Check the heating system pressure gauge reading against the value in your handover documents (manufacturer commissioning values: typically 1-2 bar) and that the filling loop is closed.
- Check the outdoor unit/air grilles are not blocked by debris, leaves or snow.
- The manual instructs unplugging the heat pump from the power supply and calling the service.
What the engineer will check
- Check water flow rate and temperature sensors.
- Check set-points and system design temperatures.
- Check refrigerant charge.
Who to ask for: heat pump engineer.
Certification: None specific.
What you might notice
Sources
- EcoSyn 80/100 Installation, Operation & Maintenance Manual Rev1.2 ↗ · Rev1.2 · page 23 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026