Better support for Underfloor Heating

Ben_A

Hi,

I would like to request better software support for underfloor heating systems in the Wired Thermostats when using relay mode.

The modulation used by the Tado Wired Thermostates is not beneficial to my system because it tries to turn the UFH on and off repeatably when NOT calling for "full heat" (i.e. when calling for either low or medium heat). UFH systems do not work well in this way.

I would like to request a software option to enable either "ON or OFF" control with no modulation within the thermostat. Without this support my boiler and UFH system is wasting time and money with the current modulation approach used by Tado.

Extra detail about my setup:

I have a Tado Wired Thermostat wired into an underfloor wiring station (Heatmiser UH4). The Heatmiser UH4 controls when the Heatmiser actuator heads are activated which in turn controls the flow of the water into the underfloor pipes (3 zones). There is a time delay on the actuator being fully on or off so that the preassure does not jump. The time delay on the actuators make the modulation approach from Tado even more useless.

I have spoken to Tado suppoprt about this over email but did not receive any indication that this problem would be raised as an improvement.

Thanks,

B

M111CJN

@Ben_A 100% agree with you.

I've been having similar issues and I've ended up augmenting it with HomeKit automation to manually set the temperature slightly higher when a certain threshold is met to artificially create a higher heat demand thereby allowing the boiler/UFH Pump to run for longer so the temperature is maintained.

Oddly enough I thought I'd let the Tado Thermostat do its thing today and it sat there for nearly two hours with 1 bar of heat demand before the room cooled even further (below the desired temp) and the heat demand level changed to 2 bars. Eventually after another hour it got back to its desired temperature.

Ben_A

@M111CJN yes exactly.

The Tado modulation is clearly designed with radiators in mind and not UFH where changes occur over a longer period. I have my UFH inside a concrete screed which means by the time the 1 or 2 bar has been requested the whole floor has been cooled to the point where it costs more to run the boiler on full to warm it back up again. I would be tempted to put my dumb thermostats back in but do want to keep the ability to schedule.

How does your Homekit automation work? You set the threshold just under the Tado setting so it boost it back up again?

M111CJN

Yeah, basically the routine is checking if the current temperature is equal to or below what I specified, if that is true it then sets the target temp 0.5 or 1.0 degree more than what I want.

This triggers a manual change on the Thermostat that is controlled by the Manual Change Timer which I have set to 30minutes and because of the temperature change it creates the artificial heat demand.

It's not that elegant and it can mean that the room warms more than I want sometimes but at least it turns the boiler on and runs the UFH Pump for a longer rather than waiting 3+ hours for the modulation to try to maintain the temp all the while the room is getting colder.

Ben_A

Thanks. Looking into this I need an Apple TV to similar to run the automation.

I might have a look into one of the API libraries to see if I can script something similar.

johnnyp78

You can pick up a HomePod mini for £89, will also do the job and now comes with additional thermometer and humidity measurement, should you need them.