H06.60 on a Baxi HP60 / Baxi Assure HP55 High Temperature Monobloc ASHP: HP inverter voltage The inverter voltage of the heat pump is too low
Short answer
On a Baxi heat pump, H06.60 means: HP inverter voltage The inverter voltage of the heat pump is too low. 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: HP inverter voltage The inverter voltage of the heat pump is too low.
Part involved: inverter module, compressor, PFC.
Likely causes:
- Check the power supply. If the power supply is correct, check that the LED indicator light is ok. Check the PN voltage: if it is 380 V, the source of the problem is generally the motherboard. If the indicator light is off, switch off the power supply, check the IGBT, check the dioxides, if the voltage is not correct, the inverter board is damaged, replace it. If there is no problem with the IGBT, this means that there are no problems with the inverter board. Check the bridge rectifier to see if the bridge voltage is correct. (Same method as for the IGBT, disconnect the power supply, check if the dioxides are damaged. normally, if F1 is present when the compressor is started up, the motherboard could be the problem. If F1 is present when the fan is started up, this could be due to the inverter board.
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.
- Check the heat pump's consumer-unit breaker / isolator is on (do not open any panels).
- 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
- Check the power supply. If the power supply is correct, check that the LED indicator light is ok. Check the PN voltage: if it is 380 V, the source of the problem is generally the motherboard. If the indicator light is off, switch off the power supply, check the IGBT, check the dioxides, if the voltage is not correct, the inverter board is damaged, replace it. If there is no problem with the IGBT, this means that there are no problems with the inverter board. Check the bridge rectifier to see if the bridge voltage is correct. (Same method as for the IGBT, disconnect the power supply, check if the dioxides are damaged. normally, if F1 is present when the compressor is started up, the motherboard could be the problem. If F1 is present when the fan is started up, this could be due to the inverter board.
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, user and service manual - Indoor unit ASHP Control ↗ · 7887625 - v04 - 22072025 · page 131 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026