Heat pumps · Error codes · Sime
HbSime · SHP M Pro
Hb on a Sime SHP M Pro: Three times PP protection and Tw_out below 7 C
Short answer
On a Sime heat pump, Hb means: Three times PP protection and Tw_out below 7 C. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: Three times PP protection and Tw_out below 7 C.
Part involved: see manual.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Resetting itself: unknown.
What you can check
- Note the code shown on the controller and the model number on the unit's rating label before contacting your installer.
- Check that the heat pump's isolator and consumer-unit breaker are on; do not open any casing.
- Check the heating system pressure gauge reads within the range your installer set (typically 1-2 bar).
- In freezing weather this fault needs prompt repair: contact your installer straight away. Do not switch the unit off at the isolator unless advised, as it may provide frost protection.
What the engineer will check
- Follow the manufacturer's troubleshooting for this code.
Who to ask for: Heat pump engineer.
Certification: Heat pump installer competence; F-gas and flammable-refrigerant (R32/R290) handling competence for any refrigerant-circuit work.
What you might notice
Sources
- Sime SHP M PRO Installation manual 6332386 R3 (IT/EN/ES/EL) ↗ · R3 · page printed p.57 (PDF p.128) · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026