Kospel Stiction / Corrosion After Long Idle Time

Heater does not start after being idle for a long period (seasonal use).

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.

Possible Causes

Stuck flow sensor turbine, Corroded electrical contacts, Dried or hardened seals in hydraulic block, Insect or dust contamination inside casing

Safety: Disconnect power and close water supply before opening the unit.

1. Flush system: Open a hot tap fully and let water run to clear air and debris.
2. Clean flow sensor: Remove and clean the flow sensor turbine and housing.
3. Clean contacts: Reseat and clean electrical connectors on the main PCB and sensors using contact cleaner.
4. Inspect seals: Check the hydraulic block for leaks or hardened seals; replace O-rings or the block if necessary.

Medium 3/5

Flow Sensor / Hydraulic Block

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