EE on a Hisense Hi-Therma Monobloc: Compressor Protection Alarm (It can not be reset from Master Controller)

What it means

The manual says: Compressor Protection Alarm (It can not be reset from Master Controller).

Part involved: compressor, inverter/driver PCB, power supply.

When it shows: This alarm code appears when alarms 02, 07, 08, 43 to 45, 47 occur three times within 6 hours.

Likely causes:

• This alarm code appears when alarms 02, 07, 08, 43 to 45, 47 occur three times within 6 hours.

Is it safe?

Switch the heat pump off at its isolator and call an engineer.

The heat pump stops until the fault clears or is reset.

Resetting itself: unknown.

Manual reset: Remove the cause; EE cannot be reset from the master controller.

What you can check

• Note the code shown on the controller and the unit model numbers (on the rating plate label) before contacting your installer.
• Check the heat pump's breaker/isolator at the consumer unit is on; do not open any casing.
• If the breaker or RCD trips repeatedly, leave the heat pump switched off and call an engineer; do not keep resetting it.

What the engineer will check

• Follow the handbook alarm-code flowchart (O.U. section from printed p.335, I.U. section from viewer p.383).
• Check supply voltage and phase balance.
• Check compressor windings and inverter/driver PCB per flowchart.
• Check heat-sink cooling and connections.

Who to ask for: Heat pump engineer.

Certification: Heat pump installer competence; F-gas / flammable-refrigerant (R290/R32) handling competence for any refrigerant-circuit work.

What you might notice

• Code shown on the wired controller (and/or the outdoor PCB display); heating/hot water may stop or run on backup heater.

Sources

• Air-to-Water Heat Pump Technical, Installation and Service Handbook - Hi-Therma Series (TCY12021017E) ↗ · TCY12021017E · page p.334 (printed; ManualsLib viewer p.355) · Reviewed 23 September 2026

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

Reviewed: 23 September 2026