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Heat pumps · Error codes · Hisense
35Hisense · Hi-Therma Monobloc (R32)

35 on a Hisense Hi-Therma Monobloc: Incorrect Setting of Indoor Unit No

Short answer

On a Hisense heat pump, 35 means: Incorrect Setting of Indoor Unit No. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.

Reviewed 23 September 2026 · 1 source

What it means

The manual says: Incorrect Setting of Indoor Unit No.

Part involved: PCB / communication wiring / settings.

Likely causes:

  • Incorrect Setting of Indoor Unit No.

Is it safe?

Does the heat pump stop?Yes
SeverityFault — clears by itself when the condition goes
Engineer needed?Yes

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

Resetting itself: unknown.

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.
  • Check the controller display is lit; a single power cycle at the isolator may be tried only if your installer or manual allows it.
  • Check controller mode/temperature/timer settings have not been changed; setup (DIP switch) errors need the installer.

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 communication wiring, terminals and fuses between units/controller.
  • Check DIP/rotary switch and address settings.
  • Replace PCB if the fault persists per the flowchart.

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

Sources

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

Reviewed: 23 September 2026