Ferroli
No Demand Recognition / Control Fault
Boiler display is on but there is no heating and no hot water demand response; boiler does not attempt to fire.
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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
Faulty room thermostat or programmer, Open-circuit demand wiring, Faulty PCB demand input, Faulty DHW flow switch on combi models
How to Fix / Troubleshooting
Safety first: Isolate power before accessing wiring.
- Check controls: Ensure the room thermostat is calling for heat and the programmer is set to ON or timed appropriately.
- Override test: Temporarily set the room thermostat to maximum and ensure any external controls are set to constant heat to see if the boiler responds.
- Hot water test (combi): Open a hot tap fully; if the boiler does not respond, the DHW flow switch or sensor may be faulty.
- Engineer checks:
- Test continuity of demand wiring from controls to boiler.
- Check DHW flow switch or turbine operation and replace if defective.
- Test PCB demand input and replace PCB if not responding.
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Repair Difficulty
Medium
3/5
Required Part
DHW Flow Switch / Turbine
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