Vaillant system experts! UFH w/ VRC430 and VR61

[joncox]

I'm trying to spec an underfloor heating system for my ground floor and tie the controls into my existing set up.

Can anyone confirm my proposed set up will work?

I currently have an S plan Vaillant 618 boiler, Unistor cylinder, controlled by a VRC430 and VR65 in the airing cupboard.

I would like to replace ground floor rads with UFH, to form 2 zones (ground and first - UFH and rads respectively). So...

1) Replace VR65 with VR61 (controls two zones)
2) Add VR81 remote control programmer to control 1st floor zone (rads)
3) retain VRC430 in ground floor hall for overall system control and UFH zone
4) Keep existing boiler and cylinder

The installer will spec the UFH pipes,manifold, pump etc. I'm just trying to get a head start on understanding what he'll need to do.

The ground floor subfloor is being entirely renewed to a solid floor w/ current insulation standards (engineered wood over), I've done my heat loss calcs, and the house is occupied all day. I don't want to start an argument on the merits of UFH.

Any comments or advice very welcome.

Thanks!

 

[simond]

I used to consider myself up to date on Vaillant controls but I have had issues with them recently over an unpaid bill and some poor customer service.

So I've only been fitting them when requested by the customer. Their customer helpline can be rude and undertrained, meanwhile the blighters email me every day with details of their £3M TV advertising campaign.

They could have better spent £500K of it transforming their customer support - but then, for a company predominantly populated by Glowworm personnel in the UK, perhaps I am asking a bit much.

Anyway, back to the question. the last time I asked Vaillant about using multi zone with domestic ecoTECs, they told me not to do it because there were certain issues still to be resolved, and it was not yet a fully supported solution in the UK on the small boilers (like yours).

I would therefore recommend you get something in writing from Vaillant regarding their support for your solution before you embark on the scheme. Remember, you may know more about the control system than your installer. That is a regular occurence on this forum.

 

[joncox]

Thanks, Simon. I have emailed Vaillant tech support, and will update the thread for interest when I get a response.

Could you elaborate on the 'certain issues' you mention w/ multi-zone on domestic Ecotecs?

 

[aido]

Did you ever get a reply from Vaillant? I am looking to do something similar with 2 zone UFH using the VR430 and VR 61 and would be grateful for any advise from from experiences

Cheers
Ado

 

[joncox]

Installation almost complete, have had plenty of contact with Vaillant. Will hope to post a fuller answer after the weekend.

 

[aido]

Thanks Jon it would be very helpful to get the full run down of your experiences with the installation. However I am trying to get mine up and running this week as the weather is beginning to turn colder. Would it be possible to list out all the electronic components you ended up purchasing to get the system up and running so that I can get them order if need be.

Thxs
Ado

 

[joncox]

Update: I finally have a fully operational system this evening.

Recap: I have had upgraded an existing Vaillant system (one zone; S plan; 618 system boiler, VRC430 (wall mounted), VR65, Unistor cylinder) to a two zone system (one UFH, one rads).

In the new installation, the VR65 has been replaced by a VR61 and a VR81 remote control added to the upstairs rad zone. The boiler remained in place.

The existing system was installed in March 08 and the VRC 430 had a software version of 1.36.

After everything UFH related was installed and commissioned, the installer and I sweated for some time over an error message given by the VR81 remote - which was supposed to control the upstairs rad zone.

The installer endlessly checked his wiring set-up (hydraulic diagram 2 in the VR61 manual), replaced ebus cables, etc etc.

Vaillant were moderately supportive but didn't really have a clue.

We finally decided the VR81 error could only be the result of a software error - and it was. As soon as the (old) VRC430 was replaced with a new one (software version 2.15 rather than 1.36) the problem has gone away.

However (at the moment) we have paid for a new VRC430, even though the existing one was working perfectly in the old S plan set-up (outside the 2 year warranty period)

The software can't be flashed/upgraded in the unit, which is idiotic.

I'm far from pleased right now. Vaillant sell a 'total system solution' but fail miserably to ensure the software is backwards compatible. Nowhere did any manual or Vaillant person say...

'you need a VRC430 with the latest software version to work with the VR61 and VR81' - but you do!

I will be pursuing Vaillant management directly and my installer is going to put considerable pressure on his rep re: paying out for a new VRC430.

Rant over!

 

[Milleniumaire]

Hi joncox,

I stumbled across your post while looking for information on adding UFH to my existing vaillant setup, which is identical to yours (although I'm aware you posted 4 years ago, so it may have changed by now).

I've already been in contact with Vaillant technical support, but I'm a little confused by what they are telling me and your post suggests they are wrong!

My setup is like your original setup;
ecoTEC plus 637 system boiler
uniSTOR unvented cylinder
VRC 430 weather compensation thermostat
VR 65 control centre

An extension has resulted in a new UFH system, which the builders' plumber has simply connected upto the existing supply and return pipes, so there is no independant control! Not only that but he's connected the supply pipe to the return bar on the manifold and the return pipe to the flow side of the manifold. Right now it doesn't work as the floor never heats up!!! To say I have absolutely no confidence in him would be an understatement, and when he turns up to fix his mistake, he's also supposed to be setting the UFH up as a separate zone, but I don't think he's aware of the "complexity" of my existing system, or maybe he does, which is why he didn't do it in the first place.

Hence I'm doing my own research and have identified that I need to "throw" the old VR 65 and replace it with a VR 61 (don't know why the installer didn't use this in the first place). I would also like to use a VR 81, however, I don't want to move the VRC 430, which currently controls the house radiators, so would like to use the VR 81 to control the temperature of the UFH in the new extension.

Based on your experience of doing it the other way around, do you think there is there any reason why this won't work? Vaillant seem to be insisting I don't use a VR 81, but use "another" thermostat instead!

The final update on your post was extremely useful to know, fortunately, my VRC 430 must be newer than your original stat as it is at version 2.15.

I assume when you replaced the VR 65 with the VR 61, it was necessary to completely re-program the VRC 430 or did CH2 simply "appear"?

I hope your still using the same email address after all this time otherwise the post is pointless!

 

[joncox]

Look, I'm not an expert nor an installer accredited in any way. I just RTFM. Some immediate observations:

1) Engage an experienced heating engineer well versed in Vaillant controls and UFH. Not the 'builder's plumber' FFS. Use the Vaillant website or local recommendations.

2) I have upgraded anyway to a VRC470 controller - all else remains as you have seen described in this thread

3) Don't expect much from 1st line Vaillant tech support. As I found, you may be more knowledgeable

4) 4 yrs ago this was a brand new suite of products. Now it's mature so I wouldn't expect any similarly fundamental software related idiocy from Vaillant.

5) Consult the various options for system diagrams in the VR61 installers' guide and match up to your desired number of zones etc. Obviously all the Vaillant components need to be a) connected by low voltage ebus to be able to talk to each other, and b) configured correctly on the 'wet' side, to ensure it works.

6) You should need both a blending/mixing valve (Esbe is a good brand) and a Vaillant low-loss header as part of the system.

re: my initial point. Any decent heating engineer experienced in Vaillant controls and UFH will sort this out readily.

 

[Milleniumaire]

Thanks for posting so quickly, and I agree with you about using a Vaillaint trained engineer.

However, I want to give the builders plumber a chance to put things right and as I don't know him, for all I know he may be a Vaillant expert!

Unfortunately, I've been unable to contact him to discuss my requirements and the builder is in a similar situation as he's currently "working away".

I'm aware of the components I need, so I'm making sure they are on site if/when he eventually turns up. Whether he knows what to do with them is another matter and if he doesn't I'll be providing the builder with the details of a local Vaillant engineer as I've paid for the builder to install the UFH as part of the extension.

Even if the plumber does manage to set things up, I may consider asking a Vaillant engineer to check the system is setup correctly, but one step at a time.

What made you upgrade to the VRC 470, especially as you had to buy another VRC 430?

 

[joncox]

1) Your call with the 'another chance'. I wouldn't!

2) I didn't (ultimately) pay for either the replacement 430 or the upgraded 470, so why not, eh. The 470 is bit easier to programme for 1st timers and has a few more tweaks

3) Just sell any 'old' or 'not required' Vaillant on ebay. It'll go quickly enough.