HF on an Ideal Heating HP290: Inverter not matched to Outdoor PCB dip switch setting
Short answer
On an Ideal Heating heat pump, HF means: Inverter not matched to Outdoor PCB dip switch setting. 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: Inverter not matched to Outdoor PCB dip switch setting.
Part involved: outdoor PCB DIP switches S5/S6.
Likely causes:
- DIP switches S5 1-4 not OFF or S6 1-4 not set to heat pump capacity; outdoor PCB or inverter PCB fault.
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
- Note the code or fault message shown on the controller/Halo and when it appeared; check the heat pump's isolator and consumer-unit breaker are on.
What the engineer will check
- Set S5 1-4 OFF and S6 to capacity (Fig 61 item 10); replace outdoor PCB then inverter PCB.
Who to ask for: Heat pump engineer competent with R290 (A3, highly flammable); refrigerant-circuit work requires Cat I/II F-gas plus City & Guilds 6187-21 or equivalent (I&M p.93 warning).
Certification: F-gas Cat I/II + C&G 6187-21 (R290) for refrigerant work; electrical work by competent person.
Sources
- HP290 Monobloc Heat Pump System - Installation & Maintenance (UIN 240080 A09) ↗ · UIN 240080 A09 · page 106 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026