Tado & Vallient Combi Boiler (what should i get)

zane99

Hi all

Having a new heating system fitted in Jan consisting of:

- Vallient EcoTEC Plus Combi Boiler
- Wet Unfloor Heating downstairs (2 zones)
- Rads upstairs (3rd zone)

Would like to use Tado but wow is it confusing trying to work out what id need to get haha.

All i want to really do is control each zone from an app. Smart Rad valves are a nice to have rather than must have.

Any advice appreciated.

policywonk

Need to take this forward in steps.

Some questions first.

1. You have a Vallient EcoTec Plus Combi. Tado can control this boiler in both dumb mode (on-off, what most engineers call relay mode, what Tado call R01 mode) and in digital mode (Tado refers to it as type D07, connected to the BUS connector). The latter digital mode improves efficiency of the boiler's use.
   1. What exact model of boiler is it? There are over two dozen with slightly different configurations. Need to clarify.
2. You have two UFH zones.
   1. Are they individually actuated by a motorised valve?
   2. Are they individually managed by a dedicated wiring centre? Can be a Heatmiser, Salus, something else.
   3. Normally there is a wired thermostat controlling UFH supply to each room, and these trigger, via the UFH wiring centre, the actuators to open and supply that room with heat.
      1. How many thermostats are there? What brand/model?
      2. Are they wireless, or controlling the UFH manifold with wired connections?
3. You have Rads upstairs.
   1. How many? Do they all have TRVs?
   2. How many bedrooms?
   3. Does your home have stone walls or is it over 200sqm in size?
   4. Have you had any problems with wireless access in your home in the past? It is often affected by the density of walls.
4. What exact model of programmer do you presently have? Is it built into the the boiler, or somewhere else?

You will need all this information before deciding on what to buy, and some of this information has to be passed onto Tado so they give you the correct instructions for the implementation. Come back and we'll help. Most of us are just end users, but we've been around the block a few times.

zane99

Wow thanks so much, ill speak with the heating engineer and get these answers ASAP

kramerica

I too have the same questions.

I have a Valiant Ecotec plus 838 combi

3 UFH heating zones on the ground floor with 3 program thermostat

on the 1st floor, another manual thermostat which has 4 rads and towel rack link.

on the 2nd floor it's another manual thermostat which has 3 rads and a towel rack

1st and 2nd floor are using the honeywell.

The plan is to replace these 2 manual thermostat. Would the v3 wired version or the wireless v3 with hotwater be more suitsuitable? I only have a combi.

No issues with wifi as I use a mesh system.

All rads have manual TRV

policywonk

@kramerica Many of the solutions will be the same but you may need a dedicated thread.

For the interim these are my thoughts:

1. Identify and replace all the thermostats (Honeywell and Heatmiser) with Tado wired ones. Your engineer will understand that the wiring is crucial to triggering the UFH zones.
2. The zone for the rads will need a wired smart thermostat to trigger the zone valve for the radiator zone.
3. If you then want each TRV on the radiators to have a role, you can later buy smart TRVs from Tado which can then instruct the wired stat fitted in (2) to follow their lead. The wired stat will still manage the boiler.
4. You need to get hold of the installation guide for your boiler. It will provide you with the wiring information.
5. Then get in touch with Tado via the app, explain that you have this specific combi boiler and you want to manage it in digitla mode. It has 3 UFH zones with Heatmiser wired thermostats, one radiator zone with a wired thermostast. Ask them for a proper plan to move from what you have presently to a Tado setting. They should respond within a week.
6. You will need to study the final wiring centre thats close to the boiler if you intend to do the wiring yourself. Are you comfortable doing it? A sparkie can get this done in less than a day.
7. Now if you hit a glitch with any of this, get stuck, come back here and we'll help.

kramerica

Thank you very much for your reply. I think I will just start with replacing the 2 Honeywell thermostat first. Looks like the easiest. I will leave the UFH alone for now since it has a programmable thermostat. So I will need two separate wired thermostats for the 1st and 2nd floor? Will it require 2 bridges? or can both thermostats connect to 1 bridge? Or can 1 wired therostat control both floors?

policywonk

@kramerica. Not quite. The thermostats arent acting as relays in this instance. Even though their wired side turn on the valves for UFH, they also communicate with the main zone controller which I presume handles the Radiator zone and boiler together. It will depend on how your S Plan was wired.

Every zone is independently calls for heat. If any calls for heat, the boiler needs to have a route to be told to turn on and at the right throttle level. The way Tado wired stats work, would summarise like this:

• Zone valves (for UFH, the radiator zone) are instructed to open when there is a call for heat initiated by the thermostat- usually a wired thermostat.
• Tado wired thermostats do that, but at the same time, wirelessly, they also talk with the specific zone controller that directly talks to the boiler.
• In this case your boiler happens to respond to digital requests, so, if you want to operate it in that mode, which saves money, one needs to standardise it all :
  • A Tado wired thermostat is installed replacing every existing wired thermostat.
  • With Tado's instructions, one will be wired directly into your boiler, via the EBUS and modulate demand through that interface.
  • The others still drive your UFH zone valves, but wirelessly link to the one that engages the Ebus wires and thus affect the modulation process.
• You only need one internet bridge.
• However you need to double check the main wiring centre's logic on how the final call for heat is passed onto the boiler - one of the thermostat's has that role.
• Hence it is important to get Tado to send you the specific instructions to install this. It isnt a simple swap, will take some thinking and you need to follow the procedure carefully, because the boiler must go into a digitallly controlled mode- and it must be placed into that mode correctly.

kramerica

I have 3 programmable thermostats for the UFH on the ground floor. 1 Thermostat each on the 1st and 2nd floor. Does this mean I need 5 wired thermostats to control the 5 different zones? You said only one needs to link directly to the boiler. and the rest connect wirelessly.

policywonk

@kramerica In my opinion, YES. The UFH thermostats would be assigned in the tado app as room devices- and there is likely to be a motorised valve dedicated to that, controlled by the UFH wiring centre. In this instance the wiring centre is the zone controller and as long as it uses Tado wired stats, its requirements will be understood by the app.

If the first floor thermostat controls a wired zone valve, you need another one there. If the same thing happens on the second floor, you need yet another one there.

Whats not clear is how your system is wired to the boiler, and thus how they cooperate to call for heat.

• Do you know how the wiring was set up to control the boiler?
• Did the engineers give you a plan?
• Do you have a hot water tank?
• You'll need to clarify these areas before making a move.

@wateroakley - do you agree?

wateroakley

@kramerica In principle, I'd agree with the advice from @policywonk. A lot depends on what is presently installed and how the system has been wired.

My advice is to collate everything about your present heating system and configuration. That will help users on the community site to help you.

The Heatmiser system in a rellies house has wireless room stats and a box that controls the UFH actuators, rads with dumb TRVs upstairs, hot water tank, all heated from an ASHP. Assuming a similar Heatmiser setup ... in principle:

• A. If you have a hot water tank, or combi pre-heat, the wireless starter kit will let you control the boiler CH and HW, relay ON and OFF. B. For plain combi, ignore the HW on the wireless receiver. The kit includes one wireless room stat.
• Three wired stat will connect to the UFH actuators for UFH ON and OFF.
• One more wireless stat.
• Tado V3+ Internet dongle plugs into an ethernet conection on your home network or broadband router. The V3+ Tado devices do not use your wifi. They connect wirelessly to the Internet Dongle using low power IEEE 802.15.4 wifi and 6LowPan protocol.

I'd suggest you ask the Tado support guys for their recommendations. They can be contacted from the chat function on the main web site. The chat 'bot' will ask lots of questions before a live person sees it, hence another reason to collate everything about your present system.

zane99

Back with some details @policywonk

Answer to your questions. So its a total new fit. there is nothing there currently the old system is being completely removed.

- Boiler is going to be 'Vallient VUW 30/40CS/1-5 (N-GB) ecoTEC plus 840"
- For the zones I have been told ill need a thermostat for each but what they will be is TBC, assume id use tado ones?
_ Zones 1 & 2 are UFH downstairs in our open plan living space
- Zone 3 consists of 3 rads downstairs (Utility room/Hallway/WC) which wont have UFH & upstairs rads
- I dont need Zone 3 to be individually controlled by rad stats. I am fine with just an overall on/off situation for the entire zone
- House is large ish and we do have a rely for the Wireless on the topfloor. But across bottom floor its never been an issue connecting to anything and that is where all 3 Zone stats will be

policywonk

@zane99 Need to check, is the 840 a combi boiler?

According to the guide that Tado makes available for professionals (an App called Tado Pro) this model uses what it calls eBUS, the D07 interface for the Ecotec 800 series. However the guide itself isnt specific enough and thats makes me a little uncomfortable.

Please would you contact Tado Sales and ask them for the specific wiring instructions for the this model of boiler, setting out the information you provided above as well as your response to my questions below?

Would you clarify three things for me?

• Zones 1, 2 and 3. Do these use two-port motorised zone valves? If so, these will need to be turned on with thermostats to drive open their ports when they call for heat.
• The UFH side. Does it have one system, with one thermostat, or are there multiple thermostats running, one dedicated to each heating loop?
• You mention that your house is large. Whats the longest distance from where the router is located to where a thermostat would be placed - and how many walls, at the worst, must a radio signal cross to do its job? This determines whether you need the X or the V series.

Your response to these questions will help.

I suspect if it is the V series (which I have actual experience of): you will need an EU wireless receiver, near the boiler, with one smart wired thermostat connected to each zone controller (motorised valve). You may need some more wired thermostats for the UFH side- but please come back and work through this with you. Tado Sales should come back quickly on this- they have a duty to provide you with a detailed installation guide.

• That guide should make it plain how the wires are routed from the wireless receiver and how it is set up.
• The wiring of the zone controllers is much easier. I can explain that when they've come back.

zane99

@policywonk

Reply from my plumber to your questions:

"Yes motorised valves will be used and you'll have a wiring centre attached to the manifold and then two thermostats connected to that, controlling each room downstairs for your zones, we just need to find out what wiring centre is compatible with the stats and/ or what one they recommend"

Distance between my internet router and boiler is about 9m through one wall. distance between router and the two zone thermostats would be a couple meters as its in one big open plan space divided by a sliding door

Ill speak to Tado support tomorrow when they are online. Thanks again

zane99

& yes combi boiler!!

policywonk

Well thats useful. Having used the V2 and V3 series and given the distances you have, it suggests to me that the V3 series will be both affordable and practical in your home.

However there is a hurdle to overcome and I agree with your plumber. With boilers that are digitally controlled , especially those which montor outgoing and incoming central heating temperatures - such as yours, your home sits right on a line which needs to be determined by the Tado Sales team.

1. Please inform them exactly what you have, the boiler, model, etc.
2. Ask them whether the Tado environment is still capable of moderating the boiler fully efficiently if:
   1. the three zone valves are pulled open and shut using Tado thermostats in relay mode, with one Tado stat being the central digital controlled device.
   2. or whether they would recommend the installaton of a Vallaint digital wiring centre to control the zone valves and Tado thermostats in digital mode talking to the boiler and the wiring centre.

At the same time, ask your plumber to write to Vallaint with the same facts and ask them to formally write back with their recommendations. Now it is important to be aware that Vallaint have a dislike of non-Vallaint products controlling their systems - and you must push back, asking for absolute clarity.

I personally believe it will be more efficient for your boiler to be accompanied by a digital controlled wiring centre, not a relay controlled wiring centre, because you are running a complex environment- but it is important that you have a few informed, evidenced views before you make your decision.

When their responses are filed, would you come back here and there are a few of us who can then chip in. Will keep your enquiry on my watch list.

zane99

@policywonk

Amazing, sent messages to both Vallient and Tado as suggested. Once I have detailed responses from both ill come back to this thread.