Question re: Vaillant Combi (ecoTec 835 Green iQ) w/ vSmart Controls

[Jaggers123]

First post, please excuse my lack of technical knowledge and the length of my post...

I recently had a plumber replace a c.30 year-old Potterton Netaheat Electronic 16/22 system boiler with a Vaillant ecoTec 835 Green iQ. The boiler is for a secondary heating system at my property and it provides hot water to one shower room, 8 radiators plus 2 heat exchangers (w/ their own independent thermostats) which provide hot water to an outdoor swimming pool and indoor spa.

The reason for converting to a combi boiler set-up was to have a more efficient set-up particularly as the shower room in this particular part of the house is only used very occasionally.

I also ordered the Vaillant vSmart Combi Control pack to go with the boiler. The electrician came today to wire everything up and noticed a problem; apparently the vSmart controller for combi's can only provide central heating control to one zone. The vSmart controller for Vaillant's system boilers can operate with more than one zone but obviously this is not compatible with my boiler.

This is quite disappointing as my current setup requires control of 3 different CH zones (rads, heat exchanger 1, heat exchanger 2). Now faced with having to install a different controller, I am assuming the implication is that I am not going to make use of the weather compensation features and 1:10 modulation which I have paid a premium for. Not sure if this is correct.

Is there a solution that you could suggest which would allow me to make use of the combi vSmart controller alongside the heat exchangers?

 

[ShaunCorbs]

Is this the unit you have ?

Vaillant vSMART Combi Control Pack | Smart Heating

 

[Jaggers123]

Is this the unit you have ?

Vaillant vSMART Combi Control Pack | Smart Heating

Yes

 

[ShaunCorbs]

In short that's just a prograble room stat wrong system for what you want

You want it set up in s + plan but you might need extra port valves etc

Will work with a combi tho

 

[Jaggers123]

In short that's just a prograble room stat wrong system for what you want

You want it set up in s + plan but you might need extra port valves etc

Will work with a combi tho

Thank you Shaun.

When you say, "s + plan but you might need extra port valves etc". Is that something the electrician could do to allow me to make use of the vSmart system specifically for the CH rads and connect up the heat exchangers separately? Or are you saying return the vSmart and get something else?

 

[ShaunCorbs]

Depends if there already installed/ what is controlling the heat exchangers ( normally fit port valves before these) and no if there's non fitted it's a plumbers job

Depends you could use the v smart for your house heating and use a timer for the heat exchangers but you would have to confirm this by phoning vaillint up

 

[Jaggers123]

I spoke to Vaillant technical support and they confirmed that the vSmart would not work within a multizone set-up like mine. I am going to return the unit and probably go for a Nest (or something similar) for the CH rads.

Thanks again for your assistance Shaun.

 

[ShaunCorbs]

I spoke to Vaillant technical support and they confirmed that the vSmart would not work within a multizone set-up like mine. I am going to return the unit and probably go for a Nest (or something similar) for the CH rads.

Thanks again for your assistance Shaun.

Np been thinking about it more and agree with vaillint it couldn't control anything but the boiler

You want something that can do 3 + zones

 

[Darren Jackson]

Drayton MiGenie Wish 3 multi channel room thermostat kit is a great simple to install alternative.

 

[tolly]

You are correct in saying you wont get weather comp unless you use vaillant controls. Im not sure if using a vr61 and a vrc470 would work on your setup though.

 

[Gasmk1]

You only need the weather comp for heating though not for the hot water,

 

[Moffski72]

Vr470 will only switch two zone valves. And I've got a feeling one of them is linked to cylinder charging so only for hot water production...although you could probably use it for Ch.

 

[jezza]

I hope that the following helps, as I was new to weather comp until very recently. It's not a direct answer to the OP's question, but the info may be useful, if a little long winded.

Converting a garage to an annex, new boiler, unvented, new kitchen, ufh in annex and various other stuff, the customer asked for weather compensating controls. I had heard of them but knew nothing. Thought it was just a programmer... silly me. Electricians had already first fixed for the new system of 2 x heating zones, underfloor zone, DHW, so when I looked further into weather comp I had a problem.

The system I ended up with is a Vaillant ecoTEC system boiler, third party unvented cylinder, and the 3 heating zones. I used the new wireless controls - VRC700f (comes with wireless receiver and external sensor), 2 remote controls VR91f, and the wiring centre/brain, VR71. I chose the wireless setup as I wasn't sure about the Ebus cables which seemed to be required by the wired setup, but in essence these are just more or less bellwire and in fact I probably could have used the wiring installed by the electrician without issues, although this is not guaranteed.

I had a bit of trouble getting a schematic from Vaillant for this configuration, but I think that this was because nobody had ever asked for one before. The one I got was dated 3 days before I got it. I also needed to call them several times with questions but we got there in the end - whilst I could wire a normal heating system easily, I felt completely out of my depth with this. It also appears that this is quite new to Vaillant, as some of the controls aren't even on their website yet.

The system uses sensors tied to the flow of the circuits, the ufh manifold, and one inserted into the pocket in the third party cylinder where the cylinder stat would normally go. I ended up connecting these sensor wires (where I had to extend them), with normal wiring, and it works OK. Apparently the potential problem with this lies with interference to the small sensor wires if they run close to normal 240v wiring. Anyway, in my case it all works OK - if I had had better knowledge form the outset, I would have used a wired system and just used bellwire or similar at the first fix stage.

But the system works. I must admit it was a massive headache (read stress) for me, with no previous experience of this type of system, but it's OK. Interestingly, the system appears to work like a combi, in that when there is HW demand the boiler ramps up to 75 degrees and the heating zones all shut down for the duration (with hindsight I would set HW to constant so that the boiler only ramps up to top up, for short periods of time). I actually have no idea if I have set the system up correctly, as it seems quite complex to me, and it's only been running since yesterday, more visits required I suspect.

I hope that this helps some, as in my experience even the tech support aren't quite sure as to precisely which components are needed for a particular system, which makes quoting quite difficult. But it's the future, apparently...

 

[Harvest Fields]

Drayton MiGenie Wish 3 multi channel room thermostat kit is a great simple to install alternative.

What about the new wireless Drayton with the wi fi trv heads. I think that does extra zones