Vaillant VR33 (with Nest) and VR66

[Mcalm01]

I posted the message to let other folks know that they have new stocks.

I will be back for assistance in getting it to work on my EcoFit Pure 415 boiler with PDHW.

 

[Sam Thorn]

Just doing this today. Just checking nothing connects the boiler to the vr66?

Are the nests connected to it?

I’m a bit confused by this too. Is the nest connected to the open term only and the vr66 still controls hw and heating under command from nest as putting in the vr33 changes ebus to opentherm? Why is the vr66 still required if nest can modulate over opentherm? Any help appreciated

 

[asoffe]

I ordered it from cvonderdelenhartog.nl too. Sorry I've not seen the recent messages for some reason. The wiring is quite straightforward. This website has useful info on the installation, including pictures, of the VR33 (Vaillant gasketel moduleren opentherm VR33 printplaat - installatie? - https://www.dailybits.be/item/vaillant-gasketel-moduleren-met-opentherm-via-vr33-printplaatje/)

 

[Mcalm01]

Thank you for the info. I'll be in touch when I am ready to set it all up. I will be getting my old Potterton Supriema replaced with a Ecofit Pure 415 and my aim is to configure an identical setup like what you have managed to do with a VR10 NTC to keep the HW Cylinder topped up when the storage water temp drops below a set threshold. I have a single 3-port valve (s-plan) and just need to figure out which wires I need to connect to the VR66. If you have a pic as you know the saying goes. it will speak louder than words.

 

[bwel]

Has anybody managed to use the VR33 with Two zones i.e two Nests on OpenTherm ?

eg image below.
Nest 1 - Central Heading (CH) Ground Floor
Nest 2 - Central Heating (CH) Upper Floor AND Hot Water (HW)

If so, do you simply link the two Nests Opentherms (OT) together, like dives on a multiple master Bus ?
Certainly eBus connections can work like this, but I'm not sure about Nests and the VR33 Opentherm

Ideally, I would like to have

• Nest 1 with a lower Target Temp (50) and Lower kWh, that better suits Underfloor Central Heating.
• Nest 2 with a High Temp (75) for the HW Cylinder Charging and the Upper Floor Central Heating radiators.

If so, would you still need to use the Opentherm alongside the VR66/65 for Hot Water Priority ?

 

[ShaunCorbs]

You can’t have more than one opentherm device sorry

 

[Registered Gas Man]

Not strictly correct. You cannot have Mike opentherm zones with Nest. Nest is all flashsy but lacks substance...

EvoHome can handle multiple opentherm zones as can EPH controls.

 

[magician2905]

Do either of these help anyone?

How to install & wire Nest thermostat for dual / multi zone system with radiators and UFH​

How to install Nest thermostat (UK) on an S plan - system with hot water cylinder​

 

[Plum47]

Hi All, can anybody advise what is the correct set-up for SYSTEM Vaillant boilers?

Currently I have the boiler with a junction box for the valves and water cylinder and a classic room thermostat (Salus, On/Off type).

I have the vr33 module as well as a tado unit. Where do I go from there? Do I simply remove the old thermostat, plug the the vr33 on the PCB, and wire tado to the 2-pin connector of the vr33?

Or instead, does the vr33 need to be connected to the junction box somehow?

Thanks

 

[SamThor]

Hi All, can anybody advise what is the correct set-up for SYSTEM Vaillant boilers?

Currently I have the boiler with a junction box for the valves and water cylinder and a classic room thermostat (Salus, On/Off type).

I have the vr33 module as well as a tado unit. Where do I go from there? Do I simply remove the old thermostat, plug the the vr33 on the PCB, and wire tado to the 2-pin connector of the vr33?

Or instead, does the vr33 need to be connected to the junction box somehow?

Thanks

I’ve just completed this install . Run a new 2 core cable from boiler to nest heatlink. Install vr33 believe it connects into x32 port . Connect the new wire to vr33 and nest heatlink, remove old thermostat. Setup nest as open therm

 

[nick_p]

Hi All, can anybody advise what is the correct set-up for SYSTEM Vaillant boilers?

I’ve just completed this install . Run a new 2 core cable from boiler to nest heatlink. Install vr33 believe it connects into x32 port . Connect the new wire to vr33 and nest heatlink, remove old thermostat. Setup nest as open therm

This is an excellent question. How do you get Nest and VR33 to work together on a SYSTEM boiler, WITHOUT a VR65/VR66. Everyone else on this thread seems to describe how they use both VR33 and VR65 /VR66 Control Centre.

Here is my experience having done exactly as SamThor describes (and also bridged the RT24 and disconnected the RT240 live):

The CH is working with fine with modulation, but the boiler is not firing when there is DHW demand from the thermostat, neither is it applying the DHW temperature when both are running. My CW and DHW valves are still being controlled by the Nest thermostat and the DHW boost/charge signal is being sent via OpenTherm (D025 shows “Ext eBus signal: Cylinder charging: On” when there is hot water demand via Nest and off when there is no demand). However, the boiler refuses to fire up, presumably because it is not connected to VR65/VR66 to know the actual status of the valve/cylinder thermostat?

Has anyone managed to install VR33 and an Opentherm thermostat on a system boiler without a Vaillant Control Center? Thanks

 

[Plum47]

This is an excellent question. How do you get Nest and VR33 to work together on a SYSTEM boiler, WITHOUT a VR65/VR66. Everyone else on this thread seems to describe how they use both VR33 and VR65 /VR66 Control Centre.

Here is my experience having done exactly as SamThor describes (and also bridged the RT24 and disconnected the RT240 live):

The CH is working with fine with modulation, but the boiler is not firing when there is DHW demand from the thermostat, neither is it applying the DHW temperature when both are running. My CW and DHW valves are still being controlled by the Nest thermostat and the DHW boost/charge signal is being sent via OpenTherm (D025 shows “Ext eBus signal: Cylinder charging: On” when there is hot water demand via Nest and off when there is no demand). However, the boiler refuses to fire up, presumably because it is not connected to VR65/VR66 to know the actual status of the valve/cylinder thermostat?

Has anyone managed to install VR33 and an Opentherm thermostat on a system boiler without a Vaillant Control Center? Thanks

I'd be happy to try things out Nick, I've ordered the module and a TADO smart thermostat. I also have a spare vr65, and currently wired via classic junction box.

The thing that puzzles me is how did the other guys manage to get it working even with the vr65.

From I understand what they did is:

1. Plug the vr33 on the PCB
2. run 2 core wire between their smart thermostat (Nest) and the vr33
3. run eBus between PCB and vr65
4. Connect the motorised valves to the vr65

If they manage to get control of DHW with this set-up, does it mean that when you select DHW with your phone, connect to the smart thermostat (Nest here), the smart thermostat will then communicate to the PCB via the vr33, which then sends a message through the PCB out to the eBus, which is then sent via eBus cable to the vr65, which will then tell the DHW valve to open and let hot water fill the tank?

That would also mean that the boiler now knows that DHW is ON and needs to stop modulating and heat more so the flow temp is above 60 degrees?

 

[nick_p]

I was able to get the Opentherm, Nest and DHW priority to work once I also installed the VR66, which effectively eliminated the S plan system. The wiring in logic is exactly as you say above Plum47.
I have written about all the steps here in a clean thread (I can't link, you have to search for it)

Vaillant Ecotec system boiler with VR66 and Opentherm (Nest)​

 

[gmartine]

Plumbing: Vaillant Ecotec system boiler with VR66 and Opentherm (Nest)

Vaillant Ecotec system boiler with VR66 and Opentherm (Nest) Hi everyone, Just wanted to share my experience with "upgrading" an S plan setup to Opentherm and Vaillant Control Center (VR66). There are a few threads on a few different forums but I wanted to share a full write-up with all the...

www.electriciansforums.net

 

[Daw____]

If you change from switch 230v to ot you need to put the link back into the 24v connection on the main board too

Hi, sorry to jump in. Do you mean the 24V RT connection bridge?
I am also thinking to connect Vr33 openTherm module to my Vailliant ecotec pro24 to work with Nest gen3.