Switching from Hive to Tado…help confirming my options please

s1cky11

Hi,

I currently have a Worcester Bosch greenstar 42CDI combi, on 2 zones (upstairs and downstairs) with Hive thermostats on each zone, 14 radiators in total.

We did have hive TRVs on each radiator but they were awful…Hive were adamant they were working perfectly, but they’d be on when the app said they weren’t, they wouldn’t come on when they were meant to and every other possible combination of this, so we got rid.

We have an annex with a lodger and young kid so want a bit more control over which rooms we heat and when. I did go round closing each TRV and running the heating for an hour to see if it actually is cheaper to run the heating with just 1 radiator eg towel warmer…turns out it is!

I’ve thought about switching to Tado TRVs and keeping the hive, but having to use 2 apps for the heating doesn’t appeal, as well as the fact that there’s no modulation with hive and the TRVs wouldn’t be able to call for heat means it’s not ideal.

I’m trying to work out how I can switch to tado fully…they told me basically that it doesn’t support zones so it’s hive with tado TRVs or nothing…I’ve read things on here which contradict that.

I’d like 2 wireless thermostats, boiler modulation, and radiator TRVs…is this possible using the EU wireless thermostats?

Can I just use 2 wired U.K. thermostats with the wireless extension (or have I misunderstood that)?

Is there anything else I may have missed or need to think about?

Appreciate any comments or suggestions.

johnnyp78

You need two devices to control your zone valves - either one wireless receiver (uk version is fine) and one wired thermostat or two wired thermostats (there is only version, no uk specific model).

Unfortunately you can’t use modulation with zone valves. After that you can add wireless temp sensors and Tado trvs as required.

Bear in mind that in larger houses there may be connection issues with the bridge.

Hunter

Like me you will have had hive active heating or combi equivalent. You will have two wired receivers somewhere with easy wiring templates once you take off the receiver lid. Really easy. Downstairs I replaced with wireless starter pack which included 3 SRVs. This leaves hive upstairs which you could also replace with a wired Tado stat. If as is likely your receiver and hence wiring is located in a spot where the new thermo stat would not be well placed you can buy an addional wireless thermo sensor, the system will then ignore the wired thermo and set temp via the additional temp sensor. For relay it easy for hive. Upstairs I kept hive as it’s a lower use zone.

Then be prepared that the Tado system will turn your boiler on and off quite a bit as part of its control logic. This is normal.

also note whilst I share your opinion of the hive TRVS, Tado SRVs temp readings are affected by the rad so either buy additional temp sensors or accept that either they will read wrong at rest or at setpoint. The good news is they close and are great……so far.

Support wise Tado are better but stretched as they deal with lack of clarity of what to buy, the premise of self install and deal with the uk customers who wonder why their boiler are turning on and off all the time. Hive support super sucked

s1cky11

@johnnyp78 so no modulation with zone valves? What’s the reason behind that? I’ve not heard about it before, is there any way of locking the zone valves open to get around this?

I’ve read that the EU wireless thermostats allow modulation but they’re out of stock. I read that the U.K. wired ones allow it, but wireless don’t. Tado didn’t reply to me about modulation, just said zones won’t work but didn’t explain why or how to resolve it

s1cky11

@Hunter i had a wired thermostat originally but when we installed the new combi in 2018 we moved it from a downstairs toilet to the utility room, I can’t even remember where the old thermostat was but I think it was upstairs somewhere…either way the wiring is lost forever. The only way to get wires upstairs now is messy and shouldn’t be required, really!

So if I put a wired thermostat in the utility with the boiler and just added 2 wireless temp sensors where I wanted them, it’d prioritise those over the wired thermostat? How does that work, is it a setting in the app? Would that have any affect on modulation and would it work with 2 zones?

Why does it cycle the boiler on and off a lot? If it has the modulation feature it’s meant to turn it down as it nears temperature but not on and off as it’s increased wear and tear?

I’ve read about some sort of manual offset for the temperature on the TRVs…it’s strange that this sort of compensation for the radiator temperatures isn’t built into the software to be honest.

Hunter

My receiver boxes are also both in the cylinder room. You will be best getting a wireless starter kit for say 1 zone, this comes with a temperature sensor wireless and bridge. You then need a wired thermostat for the second zone for the second hive receiver replacement. You will need a wireless add on temperature sensor.

This is will not enable digital connection to the boiler and load compensation, just relay operation. Multizone Tado does not exist as it does not have the capacity to open your zone valves via relay and digitally talk with your boiler.

the setting for this should be in the app but if not then support can activate. I have heard some pope, have had to contact support to get the wired thermo stat to identify as a zone controller.

you mix a few terms, modulation etc. relay operation works simply by switching the wire as together just as hive. However Tado activates the boiler on a timed frequency basis so say 4 mins every 20mins if low power is required, it judges power required not only to reach set buy also to arrest temp drop etc. your boiler modulation is an internal control loop that ensures the boiler puts out a controlled largely fixed discharged temp to your central heating. Load compensation which you get with digital control is when they vary the flow temp from the boiler to vary the heat output as setpoint is near.

the relay operation mimics the load compensation by using the on and off switching and therefore is cleverer than hive but that does translate to more boiler fires.

As you know hive TRVS are ok for temp prediction just many other issues. Tado can be way off, the only solution is to use a temperature sensor in the same room with it as the measuring device. More expensive but good result. Yes it should be in the Srv, but it is not. They are useable but you either increase setpoint until your room temp is reached or you use the offset, the problem with the offset is that at rest the temp will underread.

johnnyp78

It’s been answered by @Hunter but zone valves need binary relay connections to open and close, they’re not modulating valves. I guess it would be possible to make Opentherm zone valves that were controlled by the boiler but as far as I know, no one’s done this.

s1cky11

I thought a modulating thermostat/boiler lowered the flow temp as it got closer to target temp?

with zone valves surely they only need to be open or closed?

johnnyp78

Yup, that’s correct and why you can’t use modulation on a zone valve system.

s1cky11

So the wired thermostat apparently modulates the boiler, so can it also open/close 1 or 2 zone valves?

what if I installed a wired thermostat on each zone, in the same room as the boiler, would that work? Could I then add wireless temp sensors elsewhere on each zone?

johnnyp78

The wired thermostat isn’t connected to the boiler in a zoned system, you connect them to the zone valves, which in turn are connected to the boiler.

This might help https://support.tado.com/en/articles/3481812-how-does-tado-control-a-multi-zone-radiator-heating-system

s1cky11

Is there anyway to wire the zone valves so they both open when the heating comes on, essentially just bypassing them? I can then use the wired thermostat straight to the boiler and benefit from modulation, and add wireless temperature sensors where I need them?

johnnyp78

I’m sure this could be done but then you’d get all the zones heating every time there was a call for heat. if you’re going to go to these lengths you might as well remove the zone valves altogether. They’re largely redundant in a system with Tado trvs anyway.

s1cky11

I don’t have UFH, I’m intending on putting SRVs on each of my 14 radiators, but apparently having the heating split into 2 zones, upstairs and downstairs, is causing a lot of issues. So what I want to do is bypass the zone valves, and control each room individually instead, with a thermostat upstairs and another downstairs, to group the rooms into relevant ‘zones’ for ease of use.

Doing it this way, I think I’d also benefit from modulation…

I have to say I’m growing really tired of the tado ‘support’. It seems to be the same name responding to me each time, copy and paste generic answers, and just telling me I can’t do this or I can’t do that, but offering no explanation or alternatives.

It’s so common to zone the heating, I’m really surprised that these ‘smart’ devices haven’t been designed with this in mind.

I’ve asked for a copy of the installation instructions for Worcester Bosch greenstar 42CDI, but they won’t send me them, so you can only view the instructions once you’ve bought something. Not much use to me as a DIYer, when I’m trying to figure out what is/isn’t possible and whether it’s something I can do myself.

I’ve looked into keeping my hive boiler thermostats and adding tado SRVs, but having it split across 2 apps is problematic, and it doesn’t seem easy/possible to use something like Apple home app or IFTTT to control both. Eg if Tado Bedroom SRV boosted for 1h, then boost hive for 1h’ seems simple enough, but what if you boost a SRV at 6pm, then another at 6.30pm…I can’t see any way of easily boosting hive for ‘another hour from now’ on top of what has already been boosted.

johnnyp78

I would look into getting the zone valves removed altogether if you can, or, as you said, making them permanently open.

s1cky11

Do you know if there’s a way to wire it so…

…tado thermostat controls boiler

…when boiler switches on, both zone valves open

or

…when tado signals boiler to turn on, it also opens both zone valves

without a copy of any instructions I can’t look myself to see if this is even possible

johnnyp78

I think you’re getting to the level of needing a professional in. You would need some kind of line to keep the zone valves permanently open if you leave them installed, this isn’t something that could be done purely with Tado as it’s designed to be installed at least.

s1cky11

Why not just wire one thermostat to both zone valves, you wouldn’t get modulation but it’d open both valves at the same time which would bypass them? Would that work?

can you have 2 wireless thermostats? Tado support told me you can only have 1…I just find that hard to believe

johnnyp78

You can only have one wireless receiver, which is what they will have been telling you. As for wiring one thermostat to two zone valves, I would consult a professional.

luteijn

Why even bother closing the zone valves when boiler is off? Totally removing them is a bit much, but it ought to be able to just tell them to open once, and leave it at that, even if it just means wiring a light-switch to them to manually control them. Do these zone valves have a specific make/model that we could look up the documentation for?

s1cky11

Never thought of wiring them to their own switch! I’d rather they just stayed open. They’re Drayton ZA5 I think

luteijn

Teardown:
https://flameport.com/dont_try_at_home/product_teardowns/drayton_za5_zone_valve_actuator.cs4

So, if you do rig it permanently open, and then have a controller talk to the boiler directly:
- probably want to remove the connection from the valve's microswitch to the boiler's relay, so it won't permanently fire...
- the valve looks designed to be normally closed, opening from time to time but needing the motor to be powered constantly to fight the closing spring. Bit of a waste of power, and will cause wear..

Probably better to get the motorised bit disconnected electrically, and removed from the valve body proper, which you'd then manually turn open permanently.

s1cky11

Not sure how I could manually open it without the motor? I think it’s spring-closed to default closed like you say

Bit of a daffy job to remove them completely as well

Who knew that zone valves would be such a headache…with relatively new tech you’d think they’d consider stuff like this.

Tado gets so many good reviews on review sites, but from user comments on here and Reddit and my experience of their so called ‘support’ I’m honestly far from impressed so far

Hunter

Zone valves if Honeywell have hand jacks to lock the valve open. Given your responses I think you need a professional if you are to get anywhere meaningful.

s1cky11

If tado would just give me the instructions I’d be able to figure all of this out as far as wiring goes, for some reason they won’t. I’m not buying a thing until I know exactly what it can do, but they don’t explain anything via support, just copy and paste answers from a clipboard. On top of that as mentioned above their SRVs can’t compensate for the heat from the radiator…I don’t want to go back to hive as they’re just as awful in different ways, but having seen so many positive reviews of tado my experience so far as been disappointment after frustration after disappointment.

So far I’ve been told by tado that

…I can’t have tado at all
…but I can have tado although just the SRVs, but no explanation of how best to use that set up
…no replies when I ask about modulation or what equipment I’d need
…no replies when I ask about add ons
…the same copy and paste message to various unrelated questions
…comments that the SRVs can’t compensate for heat coming from the proximity of the radiator
…tado doesn’t work with zones (yet they have a webpage explaining that they do…and it’s 2022 come on…!) but apparently that’s a hard no from tado and they won’t discuss my options to get around this or acknowledge that I could just remove the zone valves
…no access to fitting instructions
…no access to any sort of compatibility info
…Nothing at all has actually been explained by them, there’s no chat or discussion.
…only 1 wireless device per account (again its 2022 come on…)

Surely nobody else is having this sort of experience or why would anyone buy it at all?!?

rafm5

@s1cky11 Level one support is usually a big barrier for anyone with more complex or non-standard query. I'm not referring just to tado°, it's more a generic market observation. Advisors are there to filter the traffic, not proactive with copy+paste skills only aka 'bots'. Low paid, often measured on the amount of closed (not necessary resolved) tickets.

They just want to get rid of you as soon as possible at lower cost.

Request for level two and up technician, once you find someone competent they will sort your things out.

s1cky11

That’s what I suspected but I’ve not been able to get put through to anyone more capable so far…any idea how to do that?