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Heat pumps
Heat pumps · Error codes · Kronoterm
ERROR-HeatSourceTempKronoterm · TERMOTRONIC-controlled heat pumps (legacy WP / WPL / WPLV water-water, brine-water, air-water)

ERROR-HeatSourceTemp on a Kronoterm TERMOTRONIC-controlled heat pumps: Source temperature outside operating range

Short answer

On a Kronoterm heat pump, ERROR-HeatSourceTemp means: Source temperature outside operating range. 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: Source temperature outside operating range.

Part involved: heat source.

Likely causes:

  • Source temperature outside operating range.

Is it safe?

Does the heat pump stop?Yes
SeverityFault — needs a manual reset once the cause is fixed
Engineer needed?Yes

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

Manual reset: After fixing the cause restart by holding ENTER for 3 s.

What you can check

  • Note the exact message shown on the TERMOTRONIC display.

What the engineer will check

  • Check source circulation pump/valves/strainer; authorised service.

Who to ask for: heat pump engineer.

What you might notice

Sources

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

Reviewed: 23 September 2026