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Heat pumps · Error codes · Kensa
tPKensa

tP on a Kensa heat pump: Low water pressure in the ground or heating system side (pipe relaxation or other pressure loss)

Short answer

On a Kensa heat pump, tP means: Low water pressure in the ground or heating system side (pipe relaxation or other pressure loss). The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.

Reviewed 23 September 2026 · 7 sources

What it means

The manual says: Low water pressure in the ground or heating system side (pipe relaxation or other pressure loss).

Part involved: Ground / heating circuit pressure.

When it shows: Legacy panel controller: 'Display flashes fault code tP'.

Likely causes:

  • Pressure loss in ground loop or heating circuit; should be 1-2 bar, raise above 1.8 bar.

Is it safe?

Does the heat pump stop?Yes
SeverityFault — clears by itself when the condition goes
Engineer needed?Yes

The heat pump stops until the fault clears or is reset.

Resetting itself: yes when pressure restored.

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 pressure gauge(s) if visible and note the value.

What the engineer will check

  • Check pressure gauges; raise to >1.8 bar via cold-fill/make-up (ground loop needs correct antifreeze mix); find cause of pressure loss.

Who to ask for: Heating engineer / GSHP installer / GSHP / ground-loop installer.

Certification: MCS-certified GSHP installer recommended.

What you might notice

Sources

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

Reviewed: 23 September 2026