Wiser No Heat Output / Call-for-Heat Not Reaching Boiler

Heating will not turn on even though the thermostat is calling for heat (no error code shown)

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 Heat Hub relay, Broken wire between Heat Hub and boiler, Incorrect wiring in wiring centre, Boiler lockout or internal fault

How to Fix / Troubleshooting

Safety first: Boiler and Heat Hub wiring carry mains voltage. Isolate power at the consumer unit and verify before opening any covers.

  • Check boiler status: Confirm the boiler display is on and not showing its own fault code. Reset the boiler if necessary.
  • Verify thermostat demand: Increase the setpoint several degrees above room temperature and check in the Wiser app that the room is shown as 'Heating'.
  • Observe Heat Hub: Listen for a relay click when heat is requested and check any CH indicator LED. No click may indicate a failed relay or no demand reaching the hub.
  • Inspect wiring (qualified persons only): Check that the CH relay terminals on the Heat Hub are correctly wired to the boiler or wiring centre and that no wires have come loose.
  • Bypass test (engineer only): A heating engineer may temporarily link the boiler’s call-for-heat terminals to confirm the boiler fires. If it does, but not via the Heat Hub, the hub is likely faulty and should be replaced.
Advertisements

Repair Difficulty

Hard 4/5

Required Part

Wiser Heat Hub central heating relay
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements