H06.68 on a Baxi HP60 / Baxi Assure HP55 High Temperature Monobloc ASHP: ODU air temp sensor Refrigerant outlet temperature sensor error in air side of heat exchanger of the outdoor unit

What it means

The manual says: ODU air temp sensor Refrigerant outlet temperature sensor error in air side of heat exchanger of the outdoor unit.

Part involved: temperature sensor.

Likely causes:

• The connector for sensor T3 is loose. Reconnect it. The connector for sensor T3 is wet or contains water. Drain the water and dry the connector. Add a waterproof adhesive. Sensor T3 is faulty, replace it with a new sensor.

Is it safe?

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.
• 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

• The connector for sensor T3 is loose. Reconnect it. The connector for sensor T3 is wet or contains water. Drain the water and dry the connector. Add a waterproof adhesive. Sensor T3 is faulty, replace it with a new sensor.

Who to ask for: heat pump engineer (controls / sensors).

Certification: Manufacturer-trained heat pump engineer.

What you might notice

• Error code shown on the controller
• Heating and/or hot water may stop or run in reduced/back-up mode

Sources

• Installation, user and service manual - Indoor unit ASHP Control ↗ · 7887625 - v04 - 22072025 · page 132 · Reviewed 23 September 2026

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 23 September 2026