H06.81 on a Baxi HP60 / Baxi Assure HP55 High Temperature Monobloc ASHP: Evaporator error Evaporator error in the outdoor unit
Short answer
On a Baxi heat pump, H06.81 means: Evaporator error Evaporator error in the outdoor unit. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Evaporator error Evaporator error in the outdoor unit.
Part involved: refrigerant pressure / temperature.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: yes - system restarts automatically when the cause disappears (may run in degraded/back-up mode meanwhile).
Manual reset: not required once cause removed.
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.
- The manual's user steps allow switching the system off and on once to see if the error clears; if the code returns, contact the installer.
- If the code persists or returns, contact a heat pump engineer.
What the engineer will check
- Diagnose per manufacturer service procedure (manual gives description only).
Who to ask for: heat pump / refrigeration engineer (F-gas).
Certification: F-gas certification (Category I) for refrigerant work; competence with flammable A3 refrigerant R290.
What you might notice
Sources
- Installation, user and service manual - Indoor unit ASHP Control ↗ · 7887625 - v04 - 22072025 · page 133 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026