vaillant vr65 control centre for s-plan with combi

[kevindgas]

that's the trouble with post hijackers

 

[groaner]

Thanks Mickg, I'll check again.

Bit worried that according to the Vaillant website info the Ecotec Plus System boilers will only work with the 430 weather compensator ion conjunction with a VR65 controller, elsewhere it states that the VR65 and VR61 cannot be used at the same time?

If it does work it will be a pretty cheap route to what appears to be a good fully modulating, compensated system. Pity only 2 zones though.

If it doesn't work, I'll probably look at an Opentherm compatible Boiler (say Ethos 45SD).

Vaillant apparently used to support Opentherm but no longer; if they want to go the dedicated route that's fair enough but it needs to offer full functionality.

 

[mickyg]

the VR61 replaces the VR65.
Ideally you would have, 600 boiler, vaillant cylinder(to take the NTC), VR61, VR430 and 2xVR10. That should do it. Just be careful if you do go down this route the instructions are a bit confusing for the VR61 wiring. I'm trying to get hold of a better version.
If you do go opentherm route, then a remeha avanta might be a good choice

 

[simond]

I would advise the OP to send an email to Vaillant checking they support the ecoTEC and VR61 multizone compatibility.

When I last checked they advised that it was not currently supported.

If it isn't supported, you will be in a world of pain.

 

[groaner]

Hi and thanks; good advice from both of you.

I'll send them a complete schedule of the equipment (was thinking of an Aurostor with a view to perhaps adding solar HW in the future) and ask them to confirm compatability.

Info on site is a little unclear, as with other manufacturers, any real detail on control systems and functionality missing. No woder no domestic users buy them.

It's a shame really given that the Band A boilers all score pretty similarly and these efficiency figures don't look like they mean much in reality. Assuming a well designed and correctly installed system, I believe the only way to any real savings is by using more sophisticated control technology

Cheers

 

[simond]

Info on site is a little unclear, as with other manufacturers, any real detail on control systems and functionality missing. No woder no domestic users buy them.

Most of the quality boiler manufacturers do not encourage end users to buy them, they assume their advertising will make the end user ask an installer to fit one. End users buying boilers just costs technical helpline and warranty overheads.

 

[squowse]

hi. anyone know if this is possible? vaillant tech advice are not very helpful. I know that it is meant to be used with a system boiler, but surely a combi can be used as a system boiler? ie it's a system boiler plus a hot water system as well? couldn't a combi be used as a system boiler ?

already have a ecotec plus 824 with the ebus vrc400 control which i want to continue using if possible as it modulates the boiler temperature according to the outside temperature.

want to use the vr65 (which is also ebus control) to control a couple of 2 port valves to run a second circuit in an S-Plan style. This is what it's designed for. Can't my combi boiler be controlled by it?

I am hoping that someone has tried it before.

hi, sorry to resurrect this - but i have had an idea that might work -

1) keep VRC400 weather compensating control connected via "Ebus", set to be always on (ie set very high target temperature, keep it in the cold cellar next to boiler)
2) use the "3-4" connections for switching on heat demand via external controls - room stats and 2 port valves in my case.

I realise that this is contrary to what vaillant would advise but i wonder what would happen if i did connect it up as described?

i assume that the VRC430 with VR61 will not be compatible with a combi for the same reason as the VR65?

to recap - i am trying to achieve 2 zone heating control with a vaillant combi, whilst maintaining the weather compensation.

thanks
roger

 

[Onetap]

You'd have to wire the hot water cylinder as a heating zone, i.e., s-plan plus, with priority for the hot water cylinder.

The other problem would be the weather compensation would deliver a reduced flow temperature for much of the year. You could have a change-over relay which, on HW demand, would switch out the thermistor outside sensor and switch in a resistor with a value equal to that of the thermistor at 0 degC. I don't know how the electronics would react to the outside temperature instantly swapping between 0 and 20 though.

 

[squowse]

hi, combi supplies hot water - no cylinder. i am interested what will happen if i break the "3-4" link whilst the combi is under the control of the VRC400 via the ebus interface. i am hoping that it will cancel any central heating demand.