External circulation pump cable connection.

[NexaHn]

A few days ago, I purchased a Vaillant EcoTEC Pro VUW 236/5-3 (H-INT II) gas boiler.

The installation went smoothly, and a Wilo RS 25/60 circulation pump was added alongside it.

However, the installer didn’t connect the wiring for the pump, and I’d prefer not to call an electrician just for a single cable.
My question is: where should I connect it on the motherboard?

A circulator is indicated at 230V, but that's the internal one.

I found the following information, but it is not specifically listed. Sorry, but I can't link to an English description.

 

[fixitflav]

The installation went smoothly, and a Wilo RS 25/60 circulation pump was added alongside it.

Unless I'm much mistaken that's a combi boiler, with internal pump. What is the additional Wilo pump doing?

 

[Madrab]

Not strictly being a UK boiler then things may differ a bit from the boilers that Vaillant produce for Europe. That being said, there are no external 230V rated component connections on that boiler to add an external pump that could be controlled by the boiler (overrun etc). The only 230V rated input is for a switched live from an external time/temp controller. All the other external controls are wired in through the 24V rail.

The question as to why there is an external pump added in needs to be answered first as the boiler's internal pump should be more than adequate.

 

[Stuckinarut]

X18 looks the obvious choice imo

 

[MNW67]

The manual for the UK version seems to mention fitting a secondary circuit board called VR40 in order to use an external pump. I have no idea how it works or if both pumps can be used together.

 

[MNW67]

It seems to be the same in your version of the manual:

 

[ChrisJP]

I'm puzzled why you let the installer get away with leaving the job without completing it. If he installed the pump he must have known why and what it is for. I would get him back to finish the job.

 

[MNW67]

Continuing in the spirit of European harmony, here's some multi lingual instructions and a video in French for the "2 in 7" VR 40 module:

https://www.vaillant.be/regelingen/0020008433-08-1739481.pdf