E1 on a Kensa heat pump: Loss of contact with a probe inside the heat pump
Short answer
On a Kensa heat pump, E1 means: Loss of contact with a probe inside the heat pump. 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 · 11 sources
What it means
On the Compact (single compressor)
The manual says: Loss of contact with a probe inside the heat pump.
Part involved: Temperature probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'.
Likely causes:
- Probe disconnected or faulty.
On the Twin Compressor Compact
The manual says: Loss of contact with a probe inside the heat pump.
Part involved: Temperature probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'.
Likely causes:
- Probe disconnected or faulty.
On the Evo
The manual says: T1 temperature probe error (load return).
Part involved: T1 load return probe.
When it shows: Error level per manual: Fault.
Likely causes:
- T1 probe faulty or disconnected.
On the High Temperature Compact
The manual says: Loss of contact with a probe inside the heat pump.
Part involved: Temperature probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'.
Likely causes:
- Probe disconnected or faulty.
On the High Temperature Plantroom
The manual says: Loss of contact with a probe inside the heat pump.
Part involved: Temperature probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'.
Likely causes:
- Probe disconnected or faulty.
On the Hybrid Twin Compressor
The manual says: Loss of contact with a probe inside the heat pump.
Part involved: Temperature probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'.
Likely causes:
- Probe disconnected or faulty.
On the Plantroom
The manual says: Loss of contact with a probe inside the heat pump.
Part involved: Temperature probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'.
Likely causes:
- Probe disconnected or faulty.
On the Q80 Series (Kensa Q)
The manual says: T1 temperature probe error (load return).
Part involved: T1 load return probe.
When it shows: Error level per manual: Fault.
Likely causes:
- T1 probe faulty or disconnected.
On the Shoebox
The manuals for this range word it in different ways:
- Loss of contact with a probe inside the heat pump.
- T1 temperature probe error (load return).
Part involved: Temperature probe; T1 load return probe.
When it shows: Legacy panel controller: 'Display flashes fault code E1'. Error level per manual: Fault.
Likely causes:
- Probe disconnected or faulty.
- T1 probe faulty or disconnected.
On the Shoebox NX
The manual says: T1 temperature probe error (load return).
Part involved: T1 load return probe.
When it shows: Error level per manual: Fault.
Likely causes:
- T1 probe faulty or disconnected.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: unknown.
Manual reset: unknown.
What you can check
- Note the code shown on the controller/LED; check the heat pump isolator and consumer-unit breaker are on; check thermostat/timer settings.
What the engineer will check
On the Compact (single compressor)
- Check probe connections/continuity; refer to Kensa Technical department.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended.
On the Twin Compressor Compact
- Check probe connections/continuity; refer to Kensa Technical department.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended.
On the Evo
- Follow Kensa fault table actions: T1 probe faulty or disconnected.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended; Kensa-trained.
On the High Temperature Compact
- Check probe connections/continuity; refer to Kensa Technical department.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended.
On the High Temperature Plantroom
- Check probe connections/continuity; refer to Kensa Technical department.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended.
On the Hybrid Twin Compressor
- Check probe connections/continuity; refer to Kensa Technical department.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended.
On the Plantroom
- Check probe connections/continuity; refer to Kensa Technical department.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended.
On the Q80 Series (Kensa Q)
- Follow Kensa fault table actions: T1 probe faulty or disconnected.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended; Kensa-trained.
On the Shoebox
- Check probe connections/continuity; refer to Kensa Technical department.
- Follow Kensa fault table actions: T1 probe faulty or disconnected.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended; MCS-certified GSHP installer recommended; Kensa-trained.
On the Shoebox NX
- Follow Kensa fault table actions: T1 probe faulty or disconnected.
Who to ask for: Heat pump controls engineer / Kensa technical support.
Certification: MCS-certified GSHP installer recommended; Kensa-trained.
What you might notice
Sources
- Single Compressor Compact Heat Pump Manual ↗ · Version 11 · page 41 · Reviewed 23 September 2026
- Twin Compressor Compact Heat Pump Manual ↗ · Version 14 · page 38 · Reviewed 23 September 2026
- Kensa Evo Heat Pump Installation manual ↗ · V32 · page 52 · Reviewed 23 September 2026
- High Temperature Single Compressor Compact Heat Pump Manual ↗ · Version 5 · page 41 · Reviewed 23 September 2026
- High Temperature Plant Room Heat Pump Manual ↗ · v4.1 · page 30 · Reviewed 23 September 2026
- Hybrid Twin Compressor Compact Heat Pump Manual ↗ · Version 4 · page 38 · Reviewed 23 September 2026
- Plant Room Heat Pump Manual ↗ · Version 11.1 · page 30 · Reviewed 23 September 2026
- Q80 Series Heat Pump Operational Manual ↗ · Version 2 · page 25 · Reviewed 23 September 2026
- Shoebox Heat Pump Installation and Commissioning Manual (ground array) ↗ · Version 4 · page 33 · Reviewed 23 September 2026
- Shoebox Heat Pump Operational Manual (User Manual) ↗ · Version 8 · page 28 · Reviewed 23 September 2026
- Kensa Shoebox NX heat pump Installation manual ↗ · V12 · page 42 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026