tado & multizone wet UFH

markm82

Hello,

On our first floor, we currently have a single zone UFH set-up, using a Robot manifold. The manifold has a 'dumb' TRV on it. We have an internet bridge. The dumb TRV is paired to a wireless smart thermostat which senses the temperature in the zone. This wireless thermostat is also paired to a wired thermostat which in turn is connected to the boiler to call for heat. This works fine for us.

Recently, we have renovated our second floor and attic. We have added 2 new manifolds. In the attic the manifold is single zone and we intend to set it up the same way as we have on the first floor using the same internet bridge and wired thermostat from that set-up.

The UFH plan on the second floor has multiple zones for each of the three bedrooms. I'm not sure how to configure the set-up and what equipment we need. I am currently understanding the following:

We can have a wireless smart thermostat in each of the three bedrooms to sense the temperature. We can pair each of those wireless smart thermostats to their own wired smart thermostat with the temperature-measuring function disabled (as i understand multiple wireless receivers are not officially supported). The wired thermostats are in turn each connected to the corresponding actuator on the manifold and open/close as required. Secondly, the wireless smart thermostats in each bedroom can also be paired to the same wired thermostat we have from the first floor set-up (which is connected to the boiler) to call for heat. So one wireless smart thermostat paired to two wired thermostats doing two different functions (1 - actuator control, 2 - calling for heat).

Would that create the desired outcome of controlling multiple zones, via multiple manifolds from the same tado account/app?

Corrections, confirmations, comments, improvements etc. all welcome!

Thanks!

policywonk

One wireless receiver can handle all this. Need to understand the picture.

1. Do you have individual motorised valves turning on the manifold linked pumps for the first floor and the attic?

2. Is then there a there a third zone valve and pump dedicated to the second floor?

3. Is the manifold on the second floor configured with a wiring centre that allows wired thermostats to trigger the specific room centred UFH actuators, as clusters, as you want?

If you could respond to this, perhaps could help.

markm82

1 First Floor.JPG

3 Third Floor.JPG

2 Second Floor.JPG

Thanks for the response @policywonk!

1 - No. See picture 1 for first floor set, and picture 3 for partially completed third floor set up (manifold only at present)

2 - Second floor has dedicated pump and manual valves on each of the zones - see picture 2

3 - No wiring centre (yet) as far as I can see (pic 2). I presume our contractor who will provide the motorised valves (aka actuators if i'm not mistaking names) will fit this at the same time as the actuators. I intend to provide them the wired smart thermostats at that point too so all wiring can be done at once.

A couple of updates after having talked to Tado's online support agent;

A) he proposes not use wireless smart thermostats in the bedrooms, but to use wireless temperature sensors instead

B) he proposes to replace the current wired smart thermostat on the first floor with a wireless receiver and connect that to the boiler. The wireless smart thermostat on the first floor and wireless temperatures sensors on the second floor (and third when ready) will all be paired with this wireless receiver on the first floor which will be the sole connection to the boiler

C) My own correction; we have 4 (not 3) zones for 4 (not 3) rooms upstairs, and a fifth unconnected zone (in case it's not clear why there are 5 valves in total on the upstairs manifold).

Does that help you understand the set up we're working with & envisaging?

policywonk

Reflections. I believe this thread needs to be read by someone who is more experienced by me. For now, these are my reflections

1. From '1 First Floor.jpg'. It seems that this has a wired portable thermostat, one with a wired sensor that turns on the pump for that manifold. The Tado Rad Stat's placement confuses me, by being inside that cupboard and close to the manifold. If you've found a way to have it react as a proxy thermostat to another Tado smart wall sensor that would make sense (I've not yet used the concept of having one Tado thermostat driving the actions of another, although I know it is possible often). The manifold has many loops not yet wired into actual activators - and this brings it a challenge, it that the distances are different in the loops and the heating needs of each loop (partly linked to distance but not always) can differ significantly and these need to be considered. Therefore I'd recommend the following for the floor belonging to '1 First Floor.jpg':
   1. Double check that you have a working, effective configuration between the Tado Rad Stat placed on that manifold and its actual driving sensor.
   2. Consider using Salus THB23030 wired actuators on each loop. I recommend these because they learn how to throttle their individual loops to come up to temperature swiftly. A wiring centre will be needed, to drive all of the actuators.
   3. Recommend having a two port zone motorised valve installed for this manifold, and alter the wiring so that the pump power supply is driven by the motorised zone valve, not the manifold's thermostat. Reasons are: (i) manifold thermostats moderate the temperature of water flowing through the manifold by controlling the speed of water flow (ii) your manifold pump is an excellent product, designed to offers a constant differential pressure head for the manifold- and this makes sure your boiler's CH output for this floor is deployed efficiently on the floor.
   4. The two port valve should be wired to the wiring centre, so that when there is a call for heat on that floor, (it may be the only floor calling for it, or it may not), the Tado wireless receiver will turn on the boiler, and only those zone valves which are open will use the output of the boiler.

2. From '3 Second Floor.jpg'. This is simpler. It seems that the Robot thermostat is purely a manifold thermostat, controlling the manifold's water temperature, and is not driven by ambient temperature. As with '1 First Floor.jpg' would recommend that power to the pump and actuators is wired via a wiring center, which are triggered by a local Tado wired thermostat for the floor. The wiring centre then powers (a) a dedicated two-port motorised valve for that floor (serving as a zone valve) and (b) starts the pump for that manifold.

3. From '2 Third Floor.jpg'. Same idea. A local wiring centre is installed, driving the local floor's UFH actuators. This is driven by a Wired Tado thermostat, which calls for heat, turning on the actuators and, if you agree, triggers the two port motorised zone valve for the floor.

Now the concepts so far offered carry a simple structure. (a) Make sure each floor has its own motorised zone valve (b) have a wiring centre on each floor, with enough actuator controls to handle the number of loops, (c) trigger the call for heat with Tado wired thermostats.

I hope the way I have explained this is easy to grasp. You may decide to make compromises on this approach:

i) You may elect not to fit motorised zone valves for each floor because you dont have to call a plumber in to fit them. I recommend them because these will, within a year, pay for themselves. However it is your call.

ii) Wiring centres are, I believe, essential because the pumps can draw as much as 10 amps when starting up or at full throttle. Thats more than a Tado thermostat can handle -and usually UFH wiring centres have relays capable of handling that load.

iii) You can then layer Tado wireless sensors in each floor, setting up the Tado wired thermostats as proxy zone controllers. The wireless sensors can then tell the Tado wireless receiver when they call for heat, which will fire the boiler.

In this way, the boiler will fire and start its CH pump, creating a base pressure on one side of each of the three zones. If one or more specific zones were actually calling for heat, their respective zone valves will open, their pumps will start and they will distribute heat inside their requesting zones. A wireless receiver is placed at boiler's end to help communicate the fact that there is a call for heat somewhere in the house.

I really hope this hasn't confused you. Am trying to ensure that you have a system which is consistent and operates efficiently. However I would appreciate someone else commenting here.

@wateroakley, @emcee - are you busy? Have I lost the plot here?

markm82

Thanks a lot for the thorough consideration you've given to our set-up.

We've been recommended the two port motorised zone valve by another source but i don't understand what that does exactly or how it interfaces with other components in the system. Would it replace the 'dumb' TRV in our first floor set up? Why would that be an improvement? How would it be triggered into action?

You raise an old open question for me; what is the grey thermostat on the '1 first floor.jpg' actually doing? For our first floor set-up, I understood that when the tado wireless smart thermostat sensed the temperature on the first floor required increasing, that it both called; 1) the wired thermostat connected to the boiler to supply heat and 2) the 'dumb' TRV in the picture, which subsequently opens.

That opening somehow (how?) triggers the pump and hot water from the boiler flows into the system (indeed without individual zone actuators but we've not felt any cold spots with the set up over the 2 years we've had it). So my question is; what is that grey box thermostat strapped to the manifold actually doing?

To recap;

1. Can you explain zone valve 101 - purpose and role in the system relative to other components?
2. How is the pump on our first floor (and actually, second floor too) triggered?
3. What is the grey thermostat strapped to the first floor manifold doing?

Despite these more mechanical aspects. Do you have any thoughts on tado set-up i descirbed after having talked to the agent? Mainly about the hardware and pairing proposal.

Thanks again for the thought.

policywonk

I'll focus for now on your recap questions.

1. A zone valve can be many things, but in this setting it is a two port motorised valve, that determines whether the CH water flow is shut off. When the valve is open, central heating hot water flows through it into the manifold, and fromt he manifold into the specific UFH heating zone.
   1. For further info, look up this: 'Honeywell V4043H 1056 2 Port Zone Valve Normally Closed 22mm'. It is triggered by a small current, less than 200 milliamps, but as it rolls open and shut, it throws an internal switch which can power a central heating pump.
   2. The logic goes like this:
      1. A Tado smart thermostat calls for heat. When it does, it supplies 240v (under 3amps), which can trigger a zone valve. It can be forced to do that by another wireless sensor.
      2. The zone valve motor then opens, allowing CH hot water supply to its zone, and - as the motor comes to a fully open state, it triggers another internal switch, which in turn can be used to power up the central heating pump for your UFH manifold.
      3. In practice to make this work, one installs a UFH manifold wiring centre first. This is nicely designed to simplify whats going through your head as you wire it in. It enables you to wire in the
         1. Tado wired smart thermostat
         2. Manifold's individual wiring to each UFH loop actuator (which turns the UFH loop when needed)
         3. Zone valve, which is then told to open when needed
         4. Manifold pump, which is also triggered by the call for heat.

It makes the logic easier for you to implement.

c. The Tado smart wired thermostat communicates in two ways. (i) its wires tell the wiring centre what to do on your floor, triggering the motorised zone valve, actuators, etc (ii) its wireless communication with the wireless receiver leads to the wireless receiver being told that there is a call for heat. The wireless receiver powers the boiler and the primary pump at the boiler, creating pressure on all three floors. Only those floors with an open zone valve will allow the water through - because only those need heat. This approach, with zone valves, although more expensive to start, saves loads of money on running costs.

2. The explanation in (1) above should explain the answer given to (2) now. The pump on the first floor is triggered by that grey thermostat control. The pump on the second floor seems, initially, to be permanently on- unless that power socket is controlled from somewhere else - cant tell from here.

3. My understanding is that in every UFH manifold there needs to be be a thermal sensor/stat which screws open and closed the flow of water into the manifold, ensuring that the manifold does not exceed a set temperature.

• That grey thermostat seems to be doing something else. It is acting as a switch, powering up the UFH manifold pump, when the water in the manifold loops fall below the set temperature, allowing hot water in, and turning it off when the temperature exceeds the set temperature.
• It doesn't make sense to me at all; am really not convinced that that Tado Smart TRV head should be there at all - because Tado TRV heads do not open and close in the same way as a manifold flow control thermostat. I did consider using them myself on my system in that way and found that the manifold performed better with a mechanical water temp sensing valve.
• Perhaps someone else, more experienced than me, could chip in?
• Pending that I would instead recommend a proper manifold mechanical thermostat in its place, one which works like a tap, opening and closing the inbound water flow to keep the temperature at the correct level for the manifold. The power trigger to the pump should instead be driven by a manifold wiring centre and the loops should be driven by proper UFH loop actuators.
• Hence I suggest that you consider separating the duty of setting manifold temperature, from the duty of firing the pump. Refer to my answer in (1) above.

policywonk

@markm82
Just had an update on the technology for ufh manifolds. They should have a Return Temperature Limiting valve which determines the upper temp in the water flowing in the UFH loops. It superficially looks like a radiator valve but isn't. Tado TRVs should be there.
Now UFH manifolds should use pressure differential controlled pumps. When the RTL closes or as each actuator closes it dials itself down and eventually halts.
The local UFH wiring centre should determine whether the local manifold's pump should be turned on or not.