Hoval
DHW Priority / Diverter Fault
Boiler runs but provides no domestic hot water, while heating works normally
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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
Stuck diverter valve (on combi or system with DHW), Faulty DHW flow sensor, Blocked DHW plate heat exchanger, Incorrect controller configuration
How to Fix / Troubleshooting
Safety: Isolate power and water before working on DHW components.
- Check DHW demand: Ensure the Hoval controller is set to provide DHW and that any external cylinder thermostat is calling for heat.
- Diverter valve test: When a hot tap is opened, listen for the diverter valve motor operating. If silent, the motor or valve may be stuck and require replacement.
- DHW flow sensor: Clean or replace the DHW flow sensor/turbine if it does not detect flow.
- Plate heat exchanger: Descale or replace the DHW plate heat exchanger if blocked with limescale.
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Repair Difficulty
Hard
4/5
Required Part
Diverter Valve Assembly
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