Tado X Install with Valliant Ecotec 837 Plus boiler + VR33

TFuller

Hi, I have purchased the Tado X Starter kit for use with my Ecotec 837 Plus boiler.

I am aware that Tado X requires Opentherm which my boiler doesn't natively provide, and thus have purchased a VR33 adapter to install (via the X31 socket on the main boiler pcb).

Does anyone have any further installation info/advice?

Also, what special settings do I need to use in the Tado thermostat/app to ensure this setup works?

Many thanks in advance,

Tom

policywonk

The normal approach Tado takes is to require you to contact their sales team, giving them the full configuration details, identifying whether more than one heating zone is in place, what thermostats you are replacing etc. They then provide a full set of install instructions. If you then have problems come here and the existing user base will try to help.
Would that work for you?

TFuller

Hi, thanks for this.

The question is specific to my Vaillant boiler which is effectively being retrofitted to support Tado X, so I am looking for someone who has completed this already. It's -5 here today, and I don't fancy relying on their sales team when it is not really within their remit to help! I've seen a few people have achieved this online, but not with my specific model.

FYI this is a combi boiler (no hot water tank).

1 zone, X wireless thermostat, replacing a Hive remote unit with Tado X Wireless.

Thanks

Tom

policywonk

Problem is that X is a new product and very few of us have direct experience of it, especially with what I presume is the VR33 adaptor transforming the EMS handler on the Vaillant. The Dutch are likely to have more experience but I havent seen many here. What you can do, if its of help, is to write to the Support team, making it plain that you have no heat, and this will escalate your case to get their attention.

@Emcee - would you know someone who can respond on this?

TFuller

Just to update: Tado confirmed Tado X supports the Vaillant VR33 module, but failed to provide me with a wiring diagram upon request. They told me it was in the app (it isn't). I followed all instructions from Vaillant & Tado and checked online via multiple sources and it looks correct, but the boiler will not fire and the receiver won't switch to opentherm mode. The VR-33 flashes to indicate no communication with an external controller. I tried to switch back to the hive receiver with the old wiring and the boiler now won't fire form that either. I don't have the Hive thermostat or hub as I have just moved into a new house and the previous owner took these with him (hence the need for a new thermostat).

Tado told me they have transitioned to a new customer service model and they now only communicate via chat, and even though 'no heating' constitutes an emergency, their 'install team' isn't available at weekends. So without heating until Monday and 1 degree outside. Not ideal really.

T

Emcee

Hello @TFuller

Sorry for the wait on our side. There are currently 3 chats to your name because of the phone call / different chats. Anyway, it appears 2 of our agents escalated your request. I have provided a note explaining that you have duplicate chats. Hopefully this helps clear things up among agents and gets you the answer your looking for soon.

unfortunately, I cannot provide you with instructions that take the VR33 adapter into consideration, but I suspect our agents will be able to provide you something.

policywonk

There are a couple of people who have managed to get the VR33 interface working. Have contacted them and hopefully one will chip in.

Kissarmy

@policywonk contacted me unfortunately I cannot be much help. All my Tado X kit is still in boxes and I am still running V3+ with Tado talking eBus. I have the VR33 and proved it worked - your installation is simply plugging onto X31edge connector and linking to the opentherm terminals (+ to +, - to -). You need a wireless link across the RT24 terminals which tells the boiler to heat (ebus/opentherm then seems to overrides that to control the boiler. A friend has an Ecotec Pro24 and has installed Tado X and VR33 without problem.
The only reason I have not yet taken the plunge is that I work away from home for months at a time and my wife is concerned that if something goes wrong with our 11 year old 937 and she has to book a Vaillant engineer they may refuse to work on the boiler because of the VR33. My friend would simply remove the VR33 and attach a cheap room thermostat if he needed to get a warranty repair by Vaillant. My wife understandably does not want to do this herself. I've put the project on the back burner till my current work trip away from home finishes but I'm attempting to mount the VR33 remotely from the boiler. I believe I know what the connection points on the X31edge connector do and the intention is to break out the 2 wires that do eBus and feed in 0V and 5V from a 13A USB adapter to power the VR33. I'm away till the end of Feb andvI will update the community if I get the VR33 working externally. In an ideal world of course Tado would improve the Tado X system so that it was as capable of talking to different boilers as the V3+ system is. I have been frustrated with the limitations of 1 bridge on V3+ - I have 15 TRVs and 3 WTS and the furthest ones regularly lose contact and eat through batteries. I am desperate to get the X system with multiple bridges installed. Wishing you luck with your system.

TFuller

Hiya guys,

thanks a lot for this. My boiler is out of warranty so I don't have to worry there. I agree the limitations on V3+ look to be annoying, but given Tado X can't support ebus, if I can't get opentherm working then it isn't really worth the extra money and bother over a standard relay thermostat.

The current situation: The VR33 is installed and appears to work (LED), the Tado appears to be working, but the boiler will not ignite when the thermostat calls for heat. When you say -

'a wireless bridge across the RT24 terminals'

I am not quite sure what you mean here - do you mean unbridge the RT24?

Also my boiler appears not to have the same terminals as others I have seen… below is an example of most of those I have seen online (showing RT24). Also the VR33 connection is made to the X31 via bottom of the 2 terminals on the VR33 board (I assume the top is a duplicate and that it doesn't matter which is used? I tried both).

Below are my shots of my system - you can see the 3 Burner off/24V RT/Bus terminals are different and seem to be integrated into 1 row of terminals with the rest of the terminals from the photo above.

Obviously 'Bus - +' is labelled, but there is no bridge as per the above. Is it that I need to bridge one of the other pairs that could correspond to RT24? I'm a little confused here.

Many thanks again for your help, I still haven't heard anything back from the agents at Tado dealing with the escalated case.

Thanks,

Tom

Kissarmy

Oops -bloody autocorrect. I didn't spot that it changed wire link to wireless link, no wonder I'm confusing you.

The picture you show with the annotations is of my own 937

The 2 edge connectors on the VR33 are commoned together - checked with multimeter - on my 937 the Actostor tanks connect to the second connector as they were connected to the X31 on the main board before I got the VR33

Looking at a manual for your 837 it says the boiler issupplied with terminals 3&4 linked together and that link must be removed if any external thermostat or controls are added, terminal 5 is a spare neutral connection.

If I'm right with my thinking you need to link terminals 3&4 to put the boiler in 'call for heat' mode to fire up and then the eBus or OpenTherm controls override this when they dont want heat.

TFuller

Hiya,

thanks so much for this! I see - I guess the lack of a bridge across 3-4 must be what was preventing the boiler firing. I have it working in relay mode now (turns out the PCB on the boiler was also on the fritz so the engineer replaced with a new one), but will have to try opentherm again at the weekend.

I think you just be the leading authority on all things VR33/opentherm!

Thanks again,

Tom

TFuller

Update: appears to be working!

Thanks,
T

policywonk

@TFuller. If you'd be so kind as to document, with photos a guide for other individual who have a boiler similar to yours, would be grateful.

Fatbouy

Hi, my 837 Ecotec plus seems to be working in relay mode via the vr33 module..Tado X has green light for opentherm and everything seams to be functioning but without modulation… just wondering if your boiler is modulating and whether or not it is possible to adjust boiler output via app?

Any feedback would be appreciated..