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Heat pumps
Heat pumps · Error codes · Dimplex
S22Dimplex · WPM heat pump manager platform (error-code grouping)

S22 on a Dimplex WPM heat pump manager platform: 4-way valve: the 4-way valve has not reset to its initial state after defrosting

Short answer

On a Dimplex heat pump, S22 means: 4-way valve: the 4-way valve has not reset to its initial state after defrosting. 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: 4-way valve: the 4-way valve has not reset to its initial state after defrosting.

Is it safe?

Does the heat pump stop?Partly
SeverityWarning
Engineer needed?Yes

The heat pump keeps running with some functions stopped.

Resetting itself: Unknown.

What you can check

  • Note the fault code, the heat pump model (type plate) and controller software version shown in operating data, and contact the installer/Dimplex service.

What the engineer will check

  • Investigate cause if block recurs frequently.

What you might notice

Sources

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

Reviewed: 23 September 2026