Can Tado work without a Thermostat as Boiler Controller

dazfitzg

I have a biomass boiler which heats water in a buffer tank, which is used to supply both the central heating ( a mix of radiators and underfloor heating) and to heat the domestic hot water tank.

The boiler has its own control system, which turns the boiler on and off based on the temperature sensor attached to the buffer tank. It also has its own independent circulator pump.

The heating and DHW circuits are wired into a Heatmiser UFH4 wiring centre. This controls the main circulator pump and the zone valves/actuators.

I have bought a couple of 2nd hand Wired Thermostats, for the new underfloor heating zones being installed in my new extension. These zones need to turn on and off, based on a call for heat in the new rooms.

It would appear that one of my thermostats has registered itself as the boiler controller, this causes the thermostat to be very sluggish in turning the relay on and off, while the other thermostat's relay responds within seconds. Since the boiler is protected from cyclic heat activations by its own control circuit, I don't need a dedicated Tado boiler controller.

Is there a way to reset a Tado Wired Thermostat, so that it is just a thermostat and not a boiler controller?

Thanks for any help

Darren

johnnyp78

I suspect you’ll need to tell Tado support to remove it as a zone controller, assuming it’s possible not to have one.

dazfitzg

I had a web chat with a support operative. They insisted that the thermostat was working as it should be, and that the delay of up to a couple of minutes turning on and off was a communication delay.

The two thermostats are slightly different; one has an extra set of pins, and it is this one that has the delay activating the relay. I have used the turn everything off and boost everything actions to activate both thermostats, and both respond with an updated screen within seconds displaying the new setpoint; then you will hear one relay click, followed by the other a minute or so later. So, if communication were the problem, I wouldn't get an updated setpoint.

It could just be down to different firmware versions. I have used the Installer App to check that their firmware versions are both up to date.

My original theory was that there was an issue relating to the fact that one was showing as connected to the boiler in the installer app and that the relay only turned on and off when no other devices were calling for heat. The delay was so long that, coincidentally, as I tried setting the other thermostat both relays fired at almost the same time.

It's by no means ideal to have different behaviours on similar thermostats, and as long as the delay doesn't get too long it shouldn't make any noticeable difference to my heating control.

I still don't see the distinction that the Installer App makes between the device "Controlling the Boiler" and other devices. It correctly lists the 2 thermostats and the gateway on the connections tab, but insists on preferring one thermostat over the other on the System Check page, even if the thermostats were added in a different order, and only shows that device.

Once I have these working as zone controllers, I will be looking to replace the rest of my heating controls, with Tado.

I will be adding an extension kit/add-on receiver for the hot water and Tado TRV heads for the radiators, and a couple more wired thermostats for the remaining underfloor heating. I just hope that they behave consistently. I guess I just have to remember to wait a couple of minutes for the relay to activate, before starting to look for problems.