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Heat pumps · Error codes · Ochsner
#42Ochsner · OTS touch controller alarm platform (error-code grouping)

#42 on an Ochsner OTS touch controller alarm platform: Minimum cooling/ defrosting operating temperature - troubleshooting: Insufficient heat distribution, circulation pump faulty, valve closed/air in system, check buffer charging pump and hydraulics, system temperatures too low

Short answer

On an Ochsner heat pump, #42 means: Minimum cooling/ defrosting operating temperature - troubleshooting: Insufficient heat distribution, circulation pump faulty, valve closed/air in system, check buffer charging pump and hydraulics, system temperatures too low. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.

Reviewed 23 September 2026 · 1 source

What it means

The manual says: Minimum cooling/ defrosting operating temperature - troubleshooting: Insufficient heat distribution, circulation pump faulty, valve closed/air in system, check buffer charging pump and hydraulics, system temperatures too low.

Part involved: Minimum cooling/ defrosting operating temperature.

Likely causes:

  • Insufficient heat distribution.
  • circulation pump faulty.
  • valve closed/air in system.
  • system temperatures too low.

Is it safe?

Does the heat pump stop?Not stated
Engineer needed?Yes

The manual does not say whether the heat pump stops.

Manual reset: Faults are acknowledged via the controller Alarms menu (manual section 22.2).

What you can check

  • Note the alarm number and text shown under Menu > Alarms and contact your system installer or OCHSNER customer service.

What the engineer will check

  • Insufficient heat distribution, circulation pump faulty, valve closed/air in system, check buffer charging pump and hydraulics, system temperatures too low.

Who to ask for: heating installer (OCHSNER system partner).

What you might notice

Sources

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

Reviewed: 23 September 2026