E076 on a CTC control system alarm/information platform: Sensor alarm - room sensor 3 (B13): sensor not connected, short-circuited or value outside the sensor range. If the sensor is important to operation the compressor stops
Short answer
On a CTC heat pump, E076 means: Sensor alarm - room sensor 3 (B13): sensor not connected, short-circuited or value outside the sensor range. If the sensor is important to operation the compressor stops. 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: Sensor alarm - room sensor 3 (B13): sensor not connected, short-circuited or value outside the sensor range. If the sensor is important to operation the compressor stops.
Part involved: room sensor 3 (B13).
Likely causes:
- Sensor not connected.
- Sensor short-circuited.
- Sensor value outside its range.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Manual reset: Reset alarm on the display after the fault is rectified.
What you can check
- Note the alarm code/text, the product model and serial number and contact your installer.
- For room sensor alarms, check the room sensor has not been knocked off its mounting or unplugged, without opening it.
What the engineer will check
- Check sensor wiring and connections at the control board.
- Measure sensor resistance against the NTC table in the manual and replace if faulty.
Who to ask for: heat pump controls / electrical.
Certification: Electrical competence for work inside the control panel.
What you might notice
Sources
- CTC EcoLogic XL/L/M II Installation and Maintenance Manual ↗ · 162 905 74-1 P93787 2026-02-06 · page 104 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026