tado calling for heat with nothing happening: where the demand stops

What Does Error Heat demand not delivered Mean?

When a tado control shows a heat demand and the appliance stays cold, the demand is stopping somewhere between the two. The chain runs from the thermostat, through the radio link, to a receiver or extension kit, and finally through a pair of contacts into the boiler, and each of those can fail while the one before it reports success. Applies to: tado smart thermostat systems using a wireless receiver or an extension kit between the control and the heating appliance tado has shipped several generations with different radio arrangements, including the newer tado X range which is not wired or paired like its predecessors. Match the product names on the devices you actually own to the tado support material for that generation before following any instruction. Owner-safe checks: Try to produce heat from the appliance or from any control other than tado, and note whether it works. | Look at the receiver or extension kit and note whether it shows any indication at all. | Write down anything that changed in the property recently, including furniture, appliances, routers, or a relocated thermostat. Qualified technician: Wiring between a receiver and a heating appliance carries mains voltage on United Kingdom installations, so terminal work belongs to a qualified person. | An appliance that produces no heat by any route is a heating fault and needs a Gas Safe registered engineer rather than control support.