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Heat pumps · Error codes · Waterkotte
LP-faultWaterkotte · EcoTouch Ai1 Geo (5006.5-5013.5)

LP-fault on a Waterkotte EcoTouch Ai1 Geo: Fault at input side (LP fault)

Short answer

On a Waterkotte heat pump, LP-fault means: Fault at input side (LP fault). The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.

Reviewed 23 September 2026 · 1 source

What it means

The manual says: Fault at input side (LP fault).

Likely causes:

  • Faulty extraction of water or water glycol; brine circuit insufficiently vented; glycol pour point too high; evaporator contaminated/icy; refrigerant circulation interrupted (blocked valves, contaminated filter dryer); dirt trap clogged; heat source temperature too low.

Is it safe?

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 and any text shown on the display/controller.
  • Check the heat pump isolator and consumer-unit breaker are on.

What the engineer will check

  • Work through listed causes: Faulty extraction of water or water glycol; brine circuit insufficiently vented; glycol pour point too high; evaporator contaminated/icy; refrigerant circulation interrupted (blocked valves, contaminated filter dryer); dirt trap clogged; heat source temperature too low.

Who to ask for: heat pump engineer.

Sources

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

Reviewed: 23 September 2026