Hot water constantly on?

We had Tado installed with our new boiler last week. All seems fine with the heating but the boiler was firing up at random times when nothing was calling for it to do so. We think we have realised that the hot water is constantly on so when we use the hot water, this then ignites the boiler. This is despite the app saying hot water is off.. is this a wiring issue or something we can fix ourselves? Thank you!


  • Just to add, the thermostat seems to be connected to the app however neither are communicating with the boiler.
  • There's insufficient info to give more than a generic answer, sorry. Is this a new combi boiler or system boiler with HW cylinder? Assuming you have a new system boiler with a HW cyclinder tank ... If the boiler is constantly on, or firing up (apparently random), something is calling for heat. Is the HW light on the Tado wireless receiver on or off when the HW is ON or OFF in the App? If the HW light is OFF, and the boiler is ON, the problem is most likely after the Tado controls. It could be a wiring issue, it could also be a problem with e.g. a zone valve, or ? The first call should be to the heating engineer that fitted the new boiler and controls, and ask them to look into the problem.

  • Thank you, it is a new system boiler. I have contacted the engineer. Thanks for your response.
  • Hi, I'd be interested to know what the issue turns out to be as just discovered, I've got the same problem.

    System with hot water tank.

    Everything off on app, lights off on reviever and boiler firing randomly heating the hot water?

  • collinz1
    edited April 17
    I’ve had this a couple of times and tend to find that gently banging on the wireless receiver fixes it (on the left hand side) seems to be internal wiring that’s at fault on the receiver. The wiring from mine to the boiler is solid so I can only assume it’s some internal connection that is the issue.