Buderus
Control / Demand Signal Fault
Boiler display is on but there is no response to heating or hot water demand
Advertisements
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.
Advertisements
Possible Causes
Faulty room thermostat or programmer, Broken control wiring, Incorrect control settings, Faulty boiler control board input
How to Fix / Troubleshooting
Safety: Isolate power before working on control wiring.
- 1. Check programmer and thermostat: Ensure the Buderus or third-party controller is set to call for heat and that batteries (if any) are good.
- 2. Override controls: Set the controller to constant heat and maximum temperature to force a demand.
- 3. Wiring check: Inspect the low-voltage control wiring between the boiler and room thermostat/programmer for damage or loose connections.
- 4. Link test: A technician can temporarily link the demand terminals at the boiler to see if it starts, indicating a fault in external controls.
- 5. Control board: If a demand is present but the boiler does not respond, the control board input may be defective.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Room Thermostat / Control Board
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements