UK Vaillant controls

b21playa · Dec 17, 2024

Hi all

I have Vaillant 624 running 3 circuits; a Telford unvented tank and then 2 hearings circuits (downstairs & 1st/2nd floor).

This is currently all run with 3x 2-port valves in and-plan+ configuration with Hive controls. I did have LLH fitted which was removed about a year ago for some trials with a 637 boiler. Now I’m thinking about getting this reinstated but also upgrading all the controls to Vaillant to utilise better modulation and control of temps for each circuit (possibly hw priority as well). Having a look around and I haven’t been able to pin point a list of items needed to get this all working correctly. I would need the wireless setup as as far as I can tell I need a vr71 wiring centre, vrc720f wireless (downstairs), vr92f wires (upstairs) And a sensoNet gateway.

Is this all correct?? I have attached a diagram of my setup once LLH has been installed for reference…it’s the same now minus LLH and secondary pump

John.g · Dec 19, 2024

When you do reinstate the LLH, you might consider installing a circ pump that shows the pump flowrate and power, some models like the Grundfos UPS2&UPS3 do NOT, would suggest a DAB Evosta3, or, like mine, a Wilo Yonos Pico, both of which do display the flowrate & power, this is very useful for getting the LLH primary & secondary flowrates balanced, if the primary flow is > than the secondary then this will cause primary side recirc and higher boiler return temps, less efficiency, if the secondary flow is > than the primary then the rads output will fall due to recirc on the secondary side where the cooler rad return will mix with the hot (boiler) flow and reduce the rad flowtemp causing lower output. it might also be useful to install strap on thermometers to the secondary flow&return pipes.

b21playa · Dec 19, 2024

John.g said:
When you do reinstate the LLH, you might consider installing a circ pump that shows the pump flowrate and power, some models like the Grundfos UPS2&UPS3 do NOT, would suggest a DAB Evosta3, or, like mine, a Wilo Yonos Pico, both of which do display the flowrate & power, this is very useful for getting the LLH primary & secondary flowrates balanced, if the primary flow is > than the secondary then this will cause primary side recirc and higher boiler return temps, less efficiency, if the secondary flow is > than the primary then the rads output will fall due to recirc on the secondary side where the cooler rad return will mix with the hot (boiler) flow and reduce the rad flowtemp causing lower output. it might also be useful to install strap on thermometers to the secondary flow&return pipes.

Thanks John

I have the Grundfos UPS3 pump at the moment, will look to get another that shows flow rates. Just trying to get my head around the Vaillant controls and how to wire it all up

Any particular spec I should look at the pumps, each have multiple options from a quick search

John.g · Dec 19, 2024

b21playa said:
Thanks John

I have the Grundfos UPS3 pump at the moment, will look to get another that shows flow rates. Just trying to get my head around the Vaillant controls and how to wire it all up

Any particular spec I should look at the pumps, each have multiple options from a quick search

Is this a genuine UPS3 pump??, if not take a photo of the label showing the power, amps etc.
Any of the modern A rated circ pumps have similar options but on mine, the 6M Wilo Yonos Pico, the CP (&PP) pressures can be changed incrementally in 0.1M steps which may be useful.

b21playa · Dec 19, 2024

John.g said:
Is this a genuine UPS3 pump??, if not take a photo of the label showing the power, amps etc.
Any of the modern A rated circ pumps have similar options but on mine, the 6M Wilo Yonos Pico, the CP (&PP) pressures can be changed incrementally in 0.1M steps which may be useful.

Yes it’s a genuine pump. I’ll have a look around at pumps, still got to get all the Vaillant kit. I have a vrc720f on its way, having a look around for deals on the kit so may be some time

John.g · Dec 19, 2024

b21playa said:
Yes it’s a genuine pump. I’ll have a look around at pumps, still got to get all the Vaillant kit. I have a vrc720f on its way, having a look around for deals on the kit so may be some time

The UPS3 is very powerful pump so why throw away a good few quid, just buy one of those plug in energy monitors for ~ £15/£20, the flowrate can then easily be read off the pump curves once the power is known.

b21playa · Dec 27, 2024

Merry Christmas all, just an update..

Got the vrc720f, vr71 wiring center and vr92f on its way. Just need a sensoNet and some 2core cable for ebus connections and should be good to go (fingers crossed).

Also need to extend the wiring for the 3 x 2-port valves as they aren’t long enough to reach location of wiring center. Any recommendations for connectors?

ShaunCorbs · Dec 27, 2024

Regin 5 way connectors or wago boxes the light ones and screw to the wall etc

b21playa · Dec 27, 2024

ShaunCorbs said:
Regin 5 way connectors or wago boxes the light ones and screw to the wall etc

Thanks Shaun 👍

Them Regin connectors look ideal, just ordered 3…although expensive

UK Vaillant controls

b21playa

John.g

b21playa

John.g

b21playa

John.g

b21playa

ShaunCorbs

Super Moderator

b21playa

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