HTPL on a Kensa heat pump: Load (distribution) side pressure P1 exceeds the high-pressure limit
Short answer
On a Kensa heat pump, HTPL means: Load (distribution) side pressure P1 exceeds the high-pressure limit. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 4 sources
What it means
The manual says: Load (distribution) side pressure P1 exceeds the high-pressure limit.
Part involved: P1 load pressure.
When it shows: Error level per manual: Fault.
Likely causes:
- Distribution-side pressure above the set high limit; release pressure and check water pressures in commissioning mode.
- General practice: over-filling, filling loop left open, failed expansion vessel.
Is it safe?
| 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.
Resetting itself: yes - clears when condition clears (per manual action text).
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. Read the heating-system pressure gauge (or controller pressure screen) and note the value. Read the heating-system pressure gauge and check the filling loop is closed.
What the engineer will check
- Follow Kensa fault table actions: Distribution-side pressure above the set high limit; release pressure and check water pressures in commissioning mode.
Who to ask for: Heating engineer / GSHP installer.
Certification: MCS-certified GSHP installer recommended; Kensa-trained.
What you might notice
Sources
- Kensa Evo Heat Pump Installation manual ↗ · V32 · page 51 · Reviewed 23 September 2026
- Q80 Series Heat Pump Operational Manual ↗ · Version 2 · page 24 · Reviewed 23 September 2026
- Shoebox Heat Pump Operational Manual (User Manual) ↗ · Version 8 · page 27 · Reviewed 23 September 2026
- Kensa Shoebox NX heat pump Installation manual ↗ · V12 · page 41 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026