Heat pumps · Error codes · Baxi
HLBaxi · Assure Monobloc ASHP (Assure Mono 5/7/9/12/16)
HL on a Baxi Assure Monobloc ASHP: PFC module fault
Short answer
On a Baxi heat pump, HL means: PFC module fault. 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: PFC module fault.
Part involved: inverter module, compressor, PFC.
Likely causes:
- Contact your local manufacturer.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: unknown.
Manual reset: Power OFF/ON after correcting cause (ISM 13.4).
What you can check
- Note the exact code shown on the controller and when it appeared.
- Check the outdoor unit is not blocked by leaves, debris, snow or covers and has clear airflow.
- Check the heat pump's consumer-unit breaker / isolator is on (do not open any panels).
- If the code persists or returns, contact a heat pump engineer.
What the engineer will check
- Contact your local manufacturer.
Who to ask for: heat pump engineer with electrical competence.
Certification: Qualified electrician / manufacturer-trained heat pump engineer; F-gas if refrigerant circuit is opened.
What you might notice
Sources
- Installation and owner's manual - Heat Pump air/water 'inverter' Assure Mono 5, 7, 9, 12, 16 ↗ · Back cover shows '7762758 - v05 - 19082020' (same number as the Assure Split manual - probably shared back-cover artwork) · page 74 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026