Reconnecting Tado assistance request - UFH, radiators and hot water

JPMoriarty

Hello all - apologies for the request, but my plumber / electrician is having issues getting my tado back online after a renovation and isn't having much luck getting through to the tado professional helpline, so I thought I would try here.

My system is a combi boiler with one underfloor heating (UFH) zone in the kitchen, multiple smart thermostats on water radiators through the house, and a Tado hot water extension kit.

When the system was first installed we didn't have the UFH zone, and when the UFH was added my old plumber / electrician installed a 2nd wall thermostat in next to the boiler as I understood it to trigger the UFH valve. i.e. if the wall thermostat in the kitchen ("2" below) calls for heat, then the boiler needs to providing heating and the UFH valve needs to open. There's also a pump installe din the kitchen as part of the UFH setup that needs to turn on when the UFH is calling for heat. Other than that the room thermostat ("1" below) wasn't used for measuring heat at all.

If any of the smart radiator thermostats call for heat then again the boiler needs to provide heating and the radiator valve needs to open. Hot water should be provided whenever the app calls for it.

I think that's about it. I didn't think it'd be too complicated, but the wiring is not proving easy and any assistance or suggestions would be very gratefully received. If you need any more info in addition to the above then please do ask, I'll be happy to provide it! Also happy to make a reasonable contribution via paypal to anyone who can assist if that's an incentive!

starconf

It depends on if you're using openTherm to allow Tado to regulate the temperature of the water, or is it just a standard on/off system?

In a standard system the UHF Valve should have an built-in switch wired back to the boiler controller to give the boiler the call for heat when the valve opens. The method of doing this varies between boilers, but your electrician should be able to wire this as if it were just a normal thermostat syatem. The Tado Room Thermostat(1) should then be wired to the UHF valve to open it. Room thermostat(2) should be set as the Measuring device for the kitchen, and Room Thermostat(1) should be set as the zone controller (in the Tado app).

For the radiators the same system applies, the Radiator Valve's built-in switch should be wired to the boiller controller to call for heat, and the Extension Kit should be wired to the radiator valve to open it. Each room with a Smart Radiator Thermostat should then be set to use the Extension Kit as their zone controller.

JPMoriarty

Thanks for replying, that's really clear and helpful. Can I just check, the thermostat (1) I think is set as the zone controller, but it's still appearing as a device/ room as below - should it still be in that list if it's not a measuring device and is only a zone controller? I ask because on the heating zone section (as below) it still says "when this room calls for heat..." which that "room" never should be, it should only be opening the valve and turning on the boiler. I sort of expected it might pop into the "devices" list, rather than being in the "rooms" list. Am I misunderstanding how it should work?

Grateful for any thoughts!

starconf

That's just how it works unfortunately. The Tado system assumes that a Smart Thermostat will always be part of a room so it has to be assigned to one.

You can leave it as a separate room but schedule that room to always be off. The thermostat will still open the valve when requested to by one of the smart radiator valves.

If having the extra room showing on the app is annoying, you could add thermostat(1) to one of the existing rooms(that have a Tado radiator valve). Just make sure that rooms measuring device is set to be the radiator valve not the smart themostat.

JPMoriarty

Thanks, I thought as much. Not too much of a problem, my current issue is that the valve feeding the house radiators *only* seems to open when the thermostat 1 is calling for heat. I suspect that's because its been wired incorrectly, rather than because its in the room list!

starconf

It's probably worth double checking that thermostat 1 is the Zone Controller for all rooms with radiators first before looking at the wiring.

JPMoriarty

out of interest, can i install another wireless thermostat and have two of them acting as zone controllers, in addition to the extension kit? Or is it just an extension kit plus up to one additional thermostat?

johnnyp78

A zone controller needs to be physically attached to something that it can call for heat from, so it can only be a wired thermostat or wireless receiver. I’m not sure what the limit is but it’s definitely more than two (but only one wireless receiver).

Benny4200

I just had to turn the boiler off, heating was still going even tho I had set it to off in tado

johnnyp78

Without you giving any information it’s impossible to know what the problem is.