Er68 on a Climaveneta / De Longhi Professional heat pump: Outside air sensor BT3 malfunction (automatic reset)
Short answer
On a Climaveneta / De Longhi Professional heat pump, Er68 means: Outside air sensor BT3 malfunction (automatic reset). The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause. The wording differs by model range — each is shown below.
Reviewed 23 September 2026 · 2 sources
What it means
On the De'Longhi Professional / Climaveneta AWR MTD reverse-cycle air/water heat pump with DHW
The manual says: Outside air sensor BT3 malfunction (automatic reset).
Likely causes:
- Sensor/wiring.
On the De'Longhi Professional / Climaveneta BWR MTD and MTD2 brine-to-water heat pump
The manual says: Faulty outside air temperature sensor.
Likely causes:
- Sensor or wiring fault.
Is it safe?
On the De'Longhi Professional / Climaveneta AWR MTD reverse-cycle air/water heat pump with DHW
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
On the De'Longhi Professional / Climaveneta BWR MTD and MTD2 brine-to-water heat pump
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
What you can check
- Note the code/LED pattern and the model from the rating plate, then contact a heat pump/refrigeration engineer.
- Check the heat pump's breaker/isolator at the consumer unit is on.
What the engineer will check
On the De'Longhi Professional / Climaveneta AWR MTD reverse-cycle air/water heat pump with DHW
- Check connections; replace sensor.
Who to ask for: refrigeration / heat pump engineer.
Certification: Electrical competence for work inside the unit.
On the De'Longhi Professional / Climaveneta BWR MTD and MTD2 brine-to-water heat pump
- Check electrical connections; replace component.
Who to ask for: refrigeration / heat pump engineer.
Certification: Electrical competence for work inside the unit.
What you might notice
Sources
- Climaveneta AWR MTD / AWR MTD/B 0011-0061 Installation - Operating - Service Manual (GB 01/2009) ↗ · GB 01/2009 · page 48 · Reviewed 23 September 2026
- Climaveneta WWR MTD - MTD/S, BWR MTD - MTD/S Installation and User Manual (GB 03/2010) ↗ · GB 03/2010 · page 49 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026