220 on a NIBE heat pump: High pressure alarm: Heat pump (outdoor unit) sends high pressure fault message to the controller [other NIBE documents: High pressure switch (63H1) deployed 5 times within 60 min or continuously for 60 min / High pressure switch BP1 (63H1) has tripped 5 times within 60 minutes]

What it means

The manuals for this range word it in different ways:

• High pressure alarm: Heat pump (outdoor unit) sends high pressure fault message to the controller [other NIBE documents: High pressure switch (63H1) deployed 5 times within 60 min or continuously for 60 min / High pressure switch BP1 (63H1) has tripped 5 times within 60 minutes].
• Load monitor activated: One or more power steps cannot be activated because current in at least one phase is too high.

Part involved: pressure switches/sensors, expansion valve; heating medium flow, charge pump, particle filter.

When it shows: Heat pump (outdoor unit) sends high pressure fault message to the controller; High pressure switch (63H1) deployed 5 times within 60 min or continuously for 60 min; High pressure switch BP1 (63H1) has tripped 5 times within 60 minutes; High pressure switch (63H1) deployed 5 times within 60 min or 60 min continuously One or more power steps cannot be activated because current in at least one phase is too high.

Likely causes:

• S2060: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; incorrectly connected expansion valve; service valve closed; defective baseboard AA2 (PWB1); low or no flow in heating; defective circulation pump; defective fuse F(4A) | F2050: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve not correctly connected; service valve closed; defective PWB1; low or no flow; defective circulation pump; defective fuse F(4A) | F2040: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve not correctly connected; service valve closed; defective control board; low or no flow; defective circulation pump; defective fuse F(4A).

Is it safe?

The heat pump keeps running with some functions stopped.

Resetting itself: no/unknown - Compressor blocked.

Manual reset: Reset from the controller alarm menu ('reset alarm' / 'Reset alarm and try again'); alarm recurs if the cause remains.

What you can check

• Read the alarm text and the 'info/action' help on the controller display (VVM/SMO or S-series smartguide). NIBE's manuals let the homeowner select 'reset alarm' ('Reset alarm and try again' on S-series); if the lamp returns to normal the alarm has cleared. If it comes back, do not keep resetting: select 'aid mode' ('Auxiliary operation' on S-series) if offered, so any electric additional heat keeps heat/hot water going, and contact your installer. Air source systems: check the outdoor unit is clear of leaves/snow/ice. Read the heating system pressure gauge and note the reading for your installer.
• Read the alarm text and the 'info/action' help on the controller display (VVM/SMO or S-series smartguide). NIBE's manuals let the homeowner select 'reset alarm' ('Reset alarm and try again' on S-series); if the lamp returns to normal the alarm has cleared. If it comes back, do not keep resetting: select 'aid mode' ('Auxiliary operation' on S-series) if offered, so any electric additional heat keeps heat/hot water going, and contact your installer. Read the heating system pressure gauge and check that radiator/underfloor thermostats are not all closed; check heating and hot water temperature settings have not been changed.

What the engineer will check

• Check heating medium flow, particle filter and circulation pump; check pressure switches/sensors, expansion valve, service valves and refrigerant charge (F-gas qualified). NIBE lists: Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve incorrectly connected; service valve closed; defective control board in outdoor unit; low or no flow in heating operation; defective circulation pump; defective fuse F(4A); Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; incorrectly connected expansion valve; service valve closed; defective baseboard AA2 (PWB1); low or no flow in heating; defective circulation pump; defective fuse F(4A); Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve not correctly connected; service valve closed; defective PWB1; low or no flow; defective circulation pump; defective fuse F(4A); Insufficient air circulation or blocked heat exchanger; open/short circuit on HP switch input; defective HP switch; expansion valve not correctly connected; service valve closed; defective control board; low or no flow; defective circulation pump; defective fuse F(4A).
• Check heating medium flow (pump speed/settings, particle filter, air in system), heating curve and hot water settings, correct sensor placement and flow/return connections.

Who to ask for: Heat pump engineer with F-gas qualification (NIBE-trained / NIBE PRO installer); NIBE-trained heat pump installer (NIBE PRO / VIP).

Certification: F-gas certification for refrigerant circuit work (plus flammable-refrigerant competence for R290/R32 models); None specific beyond competent heat pump installer; electrical work to BS 7671.

What you might notice

• Keeps stopping / cutting out
• No heating
• Unexpected backup / auxiliary heater use
• Short cycling
• Insufficient heating (house not warm enough)
• Slow heat-up

Sources

• TECHNICAL INFORMATION - ALARM LIST SMO 40 (TIF EN 2042-1, M12658EN) ↗ · TIF EN 2042-1 M12658EN · page 5 · Reviewed 23 September 2026

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

Reviewed: 23 September 2026