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Heat pumps · Error codes · Cool Energy
Er11Cool Energy

Er11 on a Cool Energy heat pump: Over current protection

Short answer

On a Cool Energy heat pump, Er11 means: Over current protection. 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: Over current protection.

On the Pro Range CE-H (fixed-speed)

The manual says: Password protection.

Likely causes:

  • Incorrect installer/agent control password.

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)

  • 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).

On the Pro Range CE-H (fixed-speed)

  • Input the correct control password.
  • 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

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 23 September 2026