Heating off but TADO sending constant "Switch Live" to boiler

Summertime, so heating off, but my boiler constantly running and bathroom radiator always warm.

I have a Baxi DuoTec combi boiler, starter kit, plus 8 Smart Rad valves on all rooms except bathroom - which is set to on/open.

Recently, my boiler pump has started running constantly, with the boiler firing up periodically. Suspecting the pump overrun timer I got my CORGI engineer out, who advises that the TADO controller is sending a "constant switch live" to the combi boiler.

Regardless of settings in My Tado, system off, or all rooms set to really low (= off) the pump still runs.

Service engineer says must be a fault with tado.

Please advise, If I switch boiler off, I loose hot water too !



  • Additional ..... this is a new fault,

    Like .... since the year warmed up and I turned the heating down/off

    - my system didn't do this last year .....

    soft/firm ware upgrade .... any suggestions WELCOME !!!



  • samd
    samd ✭✭✭
    edited May 2021

    @PhilHartburn can you not turn off/down Central Heating only at the Baxi as a temporary measure? Worth using the help line at tado.com cos they can investigate your system

  • Samd,

    my baxi only has a full OFF, cannot just turn CH off and keep DHW


  • @PhilHartburn im having this same issue for the past 2 days (evenings). When all my TRV's have gone to off, the boiler has remained on for upto 30mins. Only way I have been able to turn it off each time is to reset the Smart Thermostat which then turned the boiler off straight away on reset.

  • Craigg83.

    How / what did you do to your 'smart thermostat' ?

    As mentioned, All the rads in my house have smart TRV's except the bathroom, so the pump isn't fighting closed off valves.

    The boiler firing up is keeping the bathroom radiator warm, even thou everytghing should be off.

    Apparetly, the TADO box wired into the Baxi is sending a 'constant live'

    Didn't behave like this last summer ....

    Anyone from TADO on here that can help?

  • @PhilHartburn

    Did you manage to resolve this ?

    I have had the same issue, boiler overruns that I am being told is a fault with the boiler, but the engineer saying it checks out fine and is tado related. tado saying that its the boiler.

    Only way to stop is to cycle the whole power or make a change on the Smart Thermostat then change it back.

    Only happens at weekends too ?!? and usually late at night when there is no support available.

  • Anyone managed to fix this @PhilHartburn ? @andybuk
  • We have same issue. All radiators off but pump constantly on.
  • I'm having the same problem again now. I had this same problem when I first installed the unit last year and went through the process of checking all of the wiring for an incorrect connection as requested by support but to no avail. Eventually I went through the app installation process again and noticed I had ticked the pump overrun option which I knew my old boiler needed but then remembered that my new boiler did not need this so unticked the box and continued the installation process on the app and it worked !!! It had been fine for several months but is now displaying the same problem again. I am looking in the community section in the hope there is a solution somewhere ?