H02.07 on a Baxi heat pump: Water Press Error Water Pressure Error active
Short answer
On a Baxi heat pump, H02.07 means: Water Press Error Water Pressure Error active. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 2 sources
What it means
On the Assure Split ASHP (AWHP 4.5/6/8 MR + Assure AWHP-IDU 4-8 E)
The manual says: Water Press Error Water Pressure Error active.
Part involved: water flow / pressure.
Likely causes:
- Check the hydraulic pressure in the heating circuit. Check the wiring between the central unit PCB and the pressure sensor. Check the connection of the pressure sensor.
On the HP60 / Baxi Assure HP55 High Temperature Monobloc ASHP (R290)
The manual says: Water Press Error Water Pressure Error active.
Part involved: water flow / pressure.
Likely causes:
- Check the hydraulic pressure in the heating circuit. Check the wiring between the EHC–16 main PCB and the pressure sensor. Check the connection to the pressure sensor.
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.
- Read the heating system pressure gauge and report the value to your installer (the manuals quote a minimum of about 1 bar cold).
- Check the filling loop is closed.
- In freezing weather do not leave the system switched off - the manuals warn water faults left unrepaired in winter can let the pump and pipes freeze.
- 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
On the Assure Split ASHP (AWHP 4.5/6/8 MR + Assure AWHP-IDU 4-8 E)
- Check the hydraulic pressure in the heating circuit. Check the wiring between the central unit PCB and the pressure sensor. Check the connection of the pressure sensor.
Who to ask for: heating / heat pump engineer (hydraulics).
Certification: None beyond heating competence (MCS installer recommended).
On the HP60 / Baxi Assure HP55 High Temperature Monobloc ASHP (R290)
- Check the hydraulic pressure in the heating circuit. Check the wiring between the EHC–16 main PCB and the pressure sensor. Check the connection to the pressure sensor.
Who to ask for: heating / heat pump engineer (hydraulics).
Certification: None beyond heating competence (MCS installer recommended).
What you might notice
Sources
- Installation and Service Manual - Air/water 'Split Inverter' heat pump Baxi Assure, Assure AWHP-IDU 4-8 E ↗ · 7762758 - v05 - 19082020 · page 90 · Reviewed 23 September 2026
- Installation, user and service manual - Indoor unit ASHP Control ↗ · 7887625 - v04 - 22072025 · page 127 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026