Uk setup with Opentherm

msul2837

Hi all,

Firstly, sorry if this has been asked before but I’m going around in circles trying to find the answer to this.

Current setup is below..

Boiler: ideal logic heat h12
Water tank: Image added as I’m not sure what it is (looks like therma but has a Honeywell box next to it)

https://ibb.co/f260GFc

Controller: therma TQX0027
Zone 1 (downstairs): wired therma thermostat
Zone 1 (upstairs): wired therma thermostat

So I want to get my setup so it works with opentherm to maximise efficiency.

I’m thinking in need to get the wired starter kit and another wired thermostat but keep reading conflicting info. Am I correct in thinking I should go wired?

Is there anything need to change in my setup to get opentherm working?

Lastly, I also have underfloor heating (electric I think) in an extension which was build after the property was built (not built by me) which I can’t get working.

That’s a problem for another day but I don’t think I will be able to use tado for that?

Thank in advance all

policywonk

Yes. These are the roles in your context:

1. The demand for heat comes from either
   1. one of the two wired thermostats (ground floor, first floor) asking for CH heat
   2. or the hot water cylinder's thermostat.
2. When the Wired Tado thermostats call for heat, they wirelessly inform the extension kit to pass on that request and at the same time they pass on the request, through their direct wiring, to command the relevant pipe's valve to open, the pump to start, and the boiler to come into operation.

Now this website: Central Heating Controls and Zoning - DIYWiki provides the wiring profile for the S Plan plus, you have to scroll down a bit to find the diagrams. Your environment needs a small modification: ask your uncle to connect the two CH motorised valves in a way that:

• they operate on the same CH channel (from the standpoint of the extension kit)
• but they can directly ask for heat if it is needed.

Tell your uncle that the THERMA is a wiring centre and that in his mind he has to treat the extension kit as though it is the programmer. It isnt, but it sits in the same logical position in your setting. He'll likely spend most of his time working in that THERMA wiring centre. He wont find it hard, just has to map out the plan using the diagram from the DIYWiki site and make it work inside that box.

Once thats done it should work.

Now that aside, you seemed interested in Opentherm. Although you dont have that option with your boiler there are ways to improve system efficiency, significantly.

These changes enable you to recover your costs over 2-3 years.

1. Install Smart radiator valves in the bedrooms and all the rooms which are usually occupied. These will reduce wasted heat and over time it will become more efficient.
2. Install an automatic bypass valve close to your boiler so that when all the radiators no longer need heat, the boiler does not waste time and energy and will quickly shut down.

This change will improve efficiency again and enable you to recoup costs over 6 years or less.

• If your pump is a simple one, ie with one or two speeds, consider changing it for a smart pump.
• A smart pump can be set to change its power usage, and the pressure it produces by reading the differential pressure over the day.
• When each radiator closes, the pump reduces overall pressure, but maintaining the pressure on those radiators that are open, keeping it up only for those radiators. As they all close, it throttles down and encourages the boiler to shut down. Saves money over 6 years, in my case, in 3 years.

Hope this is clear. Good luck.

No. Dont work for Tado. Just a guy whose used their stuff on multiple sites as well as in my own home. Found some of what helps, what doesnt.

policywonk

This boiler, if we have the right model, seems to be relay driven, not Opentherm.
Look at this document:
https://www.manualslib.com/manual/1027473/Ideal-Logic-Heat-12.html?page=32#manual.

The TQX0027 is a 3 channel programmer. It looks after an S Plus Plan.

On this basis here are some recommendations.
1. Arrange an electrician to rework the wiring centre near these valves so that both Central Heating valves are handled as one heating channel, with the hot water tank as another heating channel. If you prefer to do the wiring yourself, come back and we'll give you the links to the rewiring needed.
2. Once that rewiring is done, install a Tado system with:
* two Tado smart wired thermostats, one for each floor, wired to control flow for each floor,
* the hot water thermostat retained
* a Tado extension kit
* a Tado internet bridge
Whilst that happens you've got to decide if the two wired thermostats in your house are correctly placed. If so your may elect to move them.
The electric system can be handled later.
Questions?

msul2837

Thank you for that very detailed answer.

Send over the links for the re-wiring as my uncle is a retired electrician and will probably give it a go.

Would the tado extension kit replace the TQX0027 then?

msul2837

Thanks again. All of that is super helpful 🙏🏽