nest to tado wiring
this is a follow up to my previous thread - https://community.tado.com/en-gb/discussion/13948/replace-nest-wireless-receiver-with-tado-wireless-receiver
finally took possession of the new property.
the boiler is an Alpha E-Tec 28 which does indeed support opentherm. UK combi boiler so will be heat only.
it currently has a google nest which i'll be removing to put in my existing Tado wired stat - albeit turning it into a wireless stat along with the EU extension kit i bought
so my question is, will this be a simple swap using the existing wiring that is in place? the next isn't currently wired up for OT just now, so i won't be doing using OT with the Tado for now (more likely i'll arrange to get the wiring done for OT at a later date)
i've attached a photo of the existing nest box and the tado extension kit i bought
once wired up i can then use my, previously, wired Tado stat as a wireless stat?
the plan then will be to eventually replace the TRVs with the tado smart TRVs.
Comments
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It should be a simple swap - you’ll get instructions from Tado. Would also be very simple to wire it to opentherm - put the two wires in the + and - connections on the extension kit and the opentherm connections on your boiler. I don’t think you need to be gas safe to change the wiring, just to change any of the components where the gas flow is, but don’t quote me on that.
The Tado smart stat should work fine in either mode - the extension kit should be set as the zone controller and the smart stat should just be a measuring device.0 -
getting instructions from Tado, these days anyway, is like pulling blood from a stone. my just be my perception but their CS seems to have taken a nose dive in recently, when i first got my Tado they were top notch. any time i've tried to ask them any sort of question they just hide behind the "use the app to get the info you need, we can't supply it to you directly), which is way most companies seem to deal with CS these days, do everything they can to avoid actually talking to you and push you to online sources which more often than not don't give the info you originally asked for.
looking at it, it looks like the 2 and 3 wires on the nest will transpose to the 2 and 4 connections on the Tado. N/L speak for themselves.
on the nest 2 is heating relay common, 3 is heating relay normally open/call for heat.
the boiler front case would need to be removed to do it, which can only be done by a gas safe registered engineer. there is no small panel that only gives you access to just the wiring.
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Yup, you’ll need to use the app to get the instructions but I don’t see how they can be different from how you’ve described.0
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I’ll be fitting it this week, should I factory reset the extension kit before attempting to configure it?
I’ve added it to the tado app (to get access to the installation instructions) and noted it has B added a “hot water” section in the all the i didn’t have before (and won’t be using)0 -
With opentherm you have control over the hot water temperature of your combi via Tado so you will be using it! I would set it to a reasonable temperature - 45ish degrees and leave it.
I didn’t factory reset when I installed my used extension kit and it worked fine, I guess you could to be on the safe side though.0 -
The extension isn’t even wired up yet, just added to the app.
However, even with opentherm, as it’s a combi boiler why would I give hot water functions to the tado? The water temp has up/down buttons on the boiler itself which is set to the desired temp.0 -
Not with Opentherm. In most cases it takes over control from the boiler so the controls on the boiler itself do nothing.0
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but as i haven't even wired it up yet, and haven't enabled opentherm anywhere, why has the app automatically added a hot water button?
all i've done so far as is to add the extension kit to the app to get access to the instructions.
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The extension kit has a hot water control for whatever way it’s wired up so it will get added when you add the extension kit to your account.0
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even if it's not wired up for hot water control? which it wouldn't be in standard relay mode.
if used in standard relay mode i certainly wouldn't want a hot water control showing up in the app, it didn't when my stat was hard wired to the boiler.
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Your thermostat doesn’t have hot water control! It’s possible that the control disappears if you change the extension kit to relay combi mode, mine’s always been wired via Opentherm so it’s always been there.0
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just using the pro installer app to change my boiler and set it in preparation of me connecting up the extension kit.
changed it to the Alpha e-tec 28, it asked for the max flow temp. consensus (although it varies who you talk to) suggest somewhere between 60 and 70 degrees. i've set it to 65 for now.
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You can usually set it lower than that. 55c is the dew point so you want the return flow temperature lower than that for maximum efficiency in a condensing boiler. I would try setting the max flow temp to 55, if your rooms aren’t reaching target temp in time then raise it.0
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at the moment i can almost certainly guess, at the moment, apart from 1 room they will struggle to reach target temp, due to the rads and pipework being very poor.
the place we've bought has had a new boiler installed last year, but they failed to take into account that most of the rads are too small for the size of rooms, and the pipework on some of them is thinner than what is now treated as standard.
add in that it's a brick wall structure (even the internal walls), and ceilings a bit higher than usual, creates a problem keeping rooms at the temp you want.
funds permitting i'm going to have to look at replacing the rads with the sizes they should be.
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ok, how do you factory reset the extension kit and the stat?
had an issue getting it to use opentherm/digital connections (boiler seems to support it but with no specific digital connection cable connections), so tried to use in relay mode, but extension mode was in opentherm mode and could see no way to reset it back to relay.
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here's what the tado professional app reports back.
and what the connections on the boiler look like at the moment (for relay mode)
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Config instructions are here. You’ll need to use your thermostat https://cdn.brandfolder.io/607DGEMS/as/fn5jmx6wp7tk6t3rmzb79mw7/Extension_Kit_Manual_-_230V_Relay_Installations.pdf
You need to rewire your boiler and extension kit if you want to use relay, otherwise you run the risk of blowing the circuit board.0 -
The boiler and extension kit are already wired up for relay, but it extension kit thinks it’s in opentherm mode, with no apparent way to tell it to use relay mode.
We didn’t attempt to wire up in opentherm mode as the boiler connections weren’t clear which they were.
Also the stat should already be in relay mode as it was using that in my previous location (albeit in wired mode)0 -
Got it working in relay mode with the extension kit
That’ll do me for now until I get clarification on the opentherm connections on the boiler
Running in single wireless stat for the time being0
