Vaillant ecoTEC 630, UFH, Heatmiser and VR66 for Cylinder Control

[peredelkin]

SUCCESS!!!

scw24489 you are an absolute legend. Your recommendation WORKS, I have just wired the cylinder's call for heat to the appropriate connector inside the boiler and voila' the boiler reads correctly the separate calls for heat/cylinder. No need for a VR66 or annoying extra wiring / eBUS.

I have bought Vaillant cable 089419, which is a "C1/C2 Connection line". It looks like it has exactly the right connector to go into my C1/C2 contact. I want everything to look as official as possible since my boiler is under warranty and cutting things is a sure-fire way to show that I have put my hands into it

 

[peredelkin]

I can confirm that Vaillant cable 089419 is indeed the correct one to connect to the C1/C2 port inside the boiler.

 

[scw24489]

My pleasure, and now I've learnt something to - never come across that cable as a spare!
There's an awful lot of stuff you can do with a vanilla ecotec that Vaillant UK will refuse to acknowledge or divulge - if you ever ring technical ask if there's anyone in on secondment from Remscheid they tend to be much more forthcoming (proud of what the kit CAN do).

Don't get me wrong I love the Ebus system too but its not always necessary or appropriate, before the VRC700/VR70/71 there was no real way to integrate UK multizoning with Ebus in any sensible manner - the demand contacts have changed that and provide another way to skin the cat where more sophisticated systems are in progress.

 

[Mcalm]

In fact if you want to use a VR61 (and possibly a VR66, I never had the pleasure being a hardened WC man ) on a 400 you need an adaptor lead (pcb edge connector to choc block) to make in the VR10 of VF1 DHW sensor into the main PCB as it was never deemed UK domestic installers were forward thinking enough to use such controls (or such features as analogue compensation on 7,8,9), good luck finding one of those in a reps case nowadays it was the only place to get them!!

@scw24489 - Hat's off to you ! You have hit the nail on the head about UK domestic installers NOT ever going to forward thinking to use WC and or Modulation controls. I got out of the trade 20 years ago. I just got fed up with customers only looking for the cheapest price and only cared about how quickly their home would heat up and they were not bothered that they were being conned into paying for high output boilers when their typical double glazed/loft insulated UK sized home had on average heat loss of about 6-7kW and they were getting these 20-30kW boilers that never condense (no energy savings) and just kept recyling ON/OFF and dying prematurely. Vaillant boilers are still factory set to I think 70 degree flow temps.

I have been given a nearly new Ecofit Pure 415 boiler that was pulled out of a new home and I was planning on using it to replace my old Potterton Heatonly. I think these 400 series boilers are GlowWarm rebadges and probably weak boilers. But I just need something to last a few years and I have ordered a VR33 OT brigde from NL that I would like to plug in and use may be a 3rd party like NEST to configure PDWH with VR10 NTC for and WC or at least modulation and could do with your thoughts about whether I can get away from needing to use the VR66 wiring centre which are not likely to be available again. I think Vaillant is just going to keep selling the so called condensing boilers and installers will keep fitting them with basic ON/OFF stats just like they have been doing for decades.

 

[scw24489]

@Mcalm - regards UK conservatism re controls - many persons end up in the trades as they are better with their hands than academic pursuits - they get shunted into work with no real education for the why's and wherefores of what they are doing other than that given by their workmates who came up the same way and therefore the vernacular persists while it still provides a profit and nothing ever changes.
Training establishments and trade bodies don't help either, eg. when I last renewed my OFT105E just a few years ago 50% of the module was still concerning single pipe and gravity circulation issues and the totality of heat loss calcs was that ridiculous CE54 worksheet.

The opportunity was missed with mandation of condensing boilers to also mandate controls and techniques for maximising the efficiency predominately by lowering (flow) and return temps which would have left the industry in much stronger position for LT renewable solutions. Boiler plus was another squandered opportunity!

Not a massive fan of the Ecofits as have always regarded aluminium hex as an inferior hex material pressed into service for a cupboard fit solution, also wait until you want to get the burner out for service, that back left nut hard under the primary pipework will have you cursing the designers!

I'm not positive, as Ecofits and I only overlapped a year or so before I ceased dealing with Vaillant (Aluminium, attitude and the farce of Ambisense sent me to Telford!), but as I recall the electronics were totally new and do not offer the flexibility of the ecotec plus to patch into the dual stats without Ebus.
Obviously the VR33 will give you an in via OT to Ebus (but no VF1 connection) but the possibilities are then totally in the hands of your OT controller.
I was never a fan of Nest but I am not aware of a WC facility, but I would expect it to try and load comp which is where the OT conflicts start to raise their head when the boiler is also trying to do the same whilst imposing it's own ramp rates and emissions control.
If you really want to pursue the OT route there are some excellent threads on automated home forums where the guys have been patching Resido Evohome into modulating control of their boilers, and some real world details of where one mans OT implementation differs from the next.

For the control you have outlined I would strongly suggest you fit a VRC700/VR70 system which will give you all you are asking and more in a no nonsense manner with no compatibility issues - the Vaillant VRC400/430/470/700/620/630 and associated modules have always been excellent bits of kit that I couldn't recommend highly enough - Vaillant's ace in the hole as far as I am concerned!! I retired before the Senso range came on the scene so don't know if that has dropped the ball but wouldn't use it myself as despise touch screens.
It might not bother you (and the secondhand situation may already have done for it) but be advised that a VR33 on a UK boiler is instant void on the warranty.

Hope that helps some!

 

[Mcalm]

@scw24489 - thank you for your detailed reply. I take everything you mentioned on board and you are spot on about reasons behind how folks end up in trades. I was also one of them, I was a hand on guy and could not see myself stuck behind a desk pushing a pen or as in now sit in front of a computer display/keyboard all day, not to mention the office politics. I was a very curious soul, my teachers at school hated me for asking questions they did not know the answer or often times contracdicted what they were teaching. I could not rest until I have gotten to the bottom of how something works and or how to fix it when it breaks down.

Getting a VRC700 series controllers is almost impossible now due to supply chain issues and the few sellers who do sell them mostly on ebay sell for astronomical prices and from talking to people only the Heat pump installers are able to pay the price because they have huge margins due to the so called taxpayer funded subsidies. I did get hold of a VR33 but later I found a good deal on ebay and managed to get a VR65 wiring centre with a VRC470 controller with WC external sensor. The seller removed it and replaced it with a Nest because he wanted to be able to control his heating using the App. I will be looking to use that with my boiler and keep the control communications strictly within the e-bus framework.

As for the Ecofit 415, yes I have read about issues with servicing the burner is pain. I have been pondering whether to find a new home for it and or look for a Ecotec Plus 618 but the problem I have is it is 20 cm taller and will not fit in my utility room and if was to find a work around it would involve cutting a new hole in the wall for the full and also we'll need to remove and redo the tiling and drilling holes in the stone worktops for routing the pipes. Whereas with the Ecofit it will connected to the existing top mounted Flow and Return pipes and just need a little extension for the gas supply pipe to connect from the bottom.

As for the warranty, i do not have any because the boiler I have is a pull out from a new build property and it 2 years old now. Nevertheless, I will try and get it fitted and operational and report back in due course.

 

[myatix]

Thought some people might be interested in this video…

Seems relavent to this tread

 

[Pars12]

Sorry to ressurect an old thread but just wanted to thank everybody in this thread for the advice.

I've got a Vaillant 637 system boiler with underfloor heating controlled by Heatmiser wired stats and heatmiser wiring centres. I wanted to have 2 flow temps - 1 low for the underfloor and a higher one for my non-Vaillant cylinder. I bought the C1/C2 cable as mentioned and it really was an easy job to connect it to the boiler wiring harness. I discovered (Accidentally!) that even touching the 2 wires on the cable together fires the boiler into hot water mode.

I simply connected the 2 wires to the orange and grey outputs from the 2 port valve that connects to my heatmiser wall stat (run in timer mode for hot water) and it works perfectly. Once the timer (and cylinder stat) tell the 2 port to switch on, the orange and grey wires tell the boiler to fire in hot water mode at the higher temp. Once the cylinder stat is satisfied it tells the whole thing to turn off again. A very quick,easy and cheap solution and you don't have to mess with any of the heatmiser controls or install any extra Vaillant wiring centres.

Happy days !