Upgrading from older Heatmiser controls to Vaillant 700/6

[nme]

hello all,

I have a 3 bed home with UFCH downstairs and radiators upstairs. I have an ecotec plus 624 system boiler and currently all my controls are the older heatmiser prt/ts type. I have 3 seperate thermostats, the first controls the upstairs radiators, and two downstairs controlling different areas of the UFCH, one of which controls the hot water.

I want to upgrade my controls and I’ve been offered a 700/6 that a friend has never gotten to installing so am considering this.

Would anyone knowledgeable be able to suggest if this is worthwhile?

I understand that I’ll need to purchase a seperate VR71 wiring centre and one / possibly two VR 91 thermostats for my current setup, although I can start with just the 700/2 as a replacement for the radiator thermostat to start with.

I’m intrigued by the weather compensation and possible cost savings in heating.

Any thoughts about this approach and the controls i’m considering?

Thanks

 

[nme]

Anybody have any insights to share around this? Been looking at the installation / Wiring Guides from Vaillant and think page 28 is the closest fit for my scenario.

Can anyone share some insight on the specific wiring of the relay to the heatmiser?

 

[Harry Bloomfield]

Can anyone share some insight on the specific wiring of the relay to the heatmiser?

Surely, the heatmiser will be done away with completely, by the new controls?

All parts of the Vaillant system will be combined and concentrated by the ebus, to the VR71, then the VR71 had the wiring out to valves, pumps and etc..

 

[nme]

Surely, the heatmiser will be done away with completely, by the new controls?

All parts of the Vaillant system will be combined and concentrated by the ebus, to the VR71, then the VR71 had the wiring out to valves, pumps and etc..

Not sure I can completely retire the heatmiser to be honest, based on the boiler schematics in that document from Vaillant.

As I understand it, Vaillant don't have any UFCH controls to manage the actuators on the manifold so that at least would remain. The boiler schematics on pg 28/9 (see below) suggests that you would retain the UFH Wiring Center, and interface between the Vaillant controls and the UFH controls via a relay. It doesn't specify the room stats, but I assume these will also stay to allow the wiring center to function. See below.

I have several questions around this, including whether the UFH zone would benefit from the boiler modulation with this setup as the heatmisers would be controlling those zones. The related boiler schematic shows that there would be NTC's onthe UFH return so the boiler would at least know what those temps were. Would that be enough for the boiler to modulate? See sensor S6 on the below:

Lots of questions around whether this is the best approach. Anyone tried this? Did it work for them? What are the alternative / better approaches?

Thanks for the help!