Vaillant ecotec plus 937

26 Oct 2012
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United Kingdom
My system comprises ectotec plus 937 combi boiler, VRC 430 weather compensator with a VRC 693 sensor.

I wish to add a second heating zone.

Can I implement this by adding a motorized valve for each heating zone and controlling them by adding a VR 61 mixer module and VR 81 room temperature controller?

My VRC is located in heating zone 1 and I would locate the VR 81 in heating zone 2

The vaillant engineer told me to use a VR 65 and not the VR 61. But the VRC 430 instruction manual indicates it should be the VR 61
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The vrc 61 is the way to go, but to do it properly the second heating zone should be a mixed circuit such as UFH...

how big is the heating circuit, how many radiators...
Zone1 1 is the main house 9 radiators

Zone 2 is an extension with 3 radiators (49sqm)
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hardly worth the agro would be for ufh in screed so you can enhance system efficiency, but for radiators, you can acheive the same result with TRVS, wireless ones or manual...assuming the other 9 radiators are always open...and the controller is correctly set up..

With radiators all you need to do is set the controller up to ensure that it maximises efficiency by matching your life style to the heating usage...

is the boiler range rated, what are the set back temperatures, what is the heating curve?

what benefits do you see with the zoning...
My wife and I work from home in the extension so day time Monday to Friday we need heat in the extension and not in the house, then in the evenings and weekends we want heat in the house and not in the extension.

I thought zoning was the best way to achieve this but TRVS valves my work.

I'll get back with the other information later thanks
I see the issue for you...the 61 does fit the an extent...the vr65 won't work with a combi as it is designed to give hot water priority..

I cant help thinking its own little boiler would be less expensive assuming that you never heated the house to an occupied temperature during work hours..
The VR65 will work just fine, but not with a VR81, just an ordinary room thermostat. The hot water circuit will switch the second heating zone.

The boiler just needs D70 changing to '1' to allow independent operation of the two port valves. This eliminates hot water priority.
now thats interesting..I did not know that... can it do two zones at once?
I don't understand what Guessman is getting at.

Does he mean using the Hot Water circuit in the VR65 as the second heating zone and using a standard on/off room stat in the cyl stat terminals?

How would you control it? The VRC wouldn't weather comp it because it would think it was HW.
I thought that too...and how do you adress it in the VRC 430...thats why you need the 61 which is precoded to address a mixed circuit, and unmixed circuit and hot water...
Alex, are you talking about a mixed circuit with UFH and rads?

In which case how can they both operate properly on the same timings?

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