A19
Herz Condensate Drain / Pump Fault

Boiler shows A19, condensate pump runs frequently or boiler shuts down

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Blocked condensate trap, kinked condensate hose, failed Herz condensate pump (if fitted), frozen external condensate pipe

How to Fix / Troubleshooting

Safety: Condensate is mildly acidic; wear gloves and eye protection. Isolate power before working on pumps.

  • Check external pipe: Inspect the external condensate discharge for freezing or blockage. Thaw gently with warm (not boiling) water if frozen.
  • Clean trap: Remove the Herz condensate trap, empty and rinse it, and ensure the internal baffles are clear.
  • Inspect hoses: Ensure all condensate hoses are free of kinks and slope continuously downward.
  • Test pump: If a condensate pump is installed, pour water into the sump and verify that it activates and discharges properly. Replace the Herz condensate pump if it fails to run.
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Repair Difficulty

Medium 3/5

Required Part

Herz condensate trap
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