Vent Axia MVHR - Boost switch wiring?

[Andehh]

We have a Vent Axia MVHR installed, and we have 3 x boost switches for the bathrooms to manually boost if (after your poo!). The MVHR was installed several months ago, and will be commissioned in a few weeks time. The MVHR installer is shrugging off the boost switch connections as he only ever installs the master one which comes with a Rj11 type connector & claims he isn't an electrician. Pisses me off this, but he won't budge. As a result my electrician needs to pick up the slack.

 

However, my electrician is scratching his head a bit on the wiring for it, with the attached diagrams being all that is offered in the manual.

 

Each boost switch needs 4 core cable, which is routed back to the MVHR. However, on the MVHR unit there is only 2 terminals per switch.

 

Can anyone shed any light on this please?

 

Boost switch:

https://www.tradesparky.com/ecommerce/downloadasset?productAssetId=571966

 

Vent Axia Manual:

https://www.vent-axia.com/sites/default/files/439817_ad.pdf

 

 

 

Thanks!

[dpmiller]

why do you think you need 4-core to a boost switch? It only needs to be a momentary contact closure.

[Andehh]

Our installer said we could have one of the main controllers (with digital readouts) per room as long as we wired 4 core. He supplied the controller's, we installed the 4 core.... Now 6 months later vent axia confirmed it can't be done!!

 

And a rocker switch off 2 core (as you've suggested) is all we can have. 

 

Why can't professional expert installers just do their job right first time. Grrr

Edited June 6, 2023 by Andehh

[Blooda]

We have the same system, but went for the wireless boost switches, but never use them.   The air clears pretty quickly, compared to traditional cr@p extractor fans, because of the constant supply flow.  The unit takes care of boosting for showers with its humidity sensor. 

 

The wireless boost switches are bit 1980's so reside in drawers

 

[JohnMo]

If you have a momentary switch as suggested above, super simple cheap as chips. Switches couple of pound, two core cable of any size will do.

 

We have them on all wet rooms, first months we used them, now almost never. And that's with the MVHR turned down considerably from initial commissioning settings.

[KineticBuser]

Is is possible to wire a lightswitch in as a momentary switch?

[JohnMo]

51 minutes ago, KineticBuser said:

Is is possible to wire a lightswitch in as a momentary switch?

My electrician, got a double switch and a momentary switch. Not all are suitable and they need to be from the same manufacturer. And merged them together, so I have a normal light switch and a momentary boost switch on a single face plate.

[anthonypherbert]

I installed a relay box (4 relays) and took feeds from the lights in Bathrooms, WC and cooker hood to activate the boost function.

This has worked really well for us.

[JohnMo]

2 hours ago, anthonypherbert said:

I installed a relay box (4 relays) and took feeds from the lights in Bathrooms, WC and cooker hood to activate the boost function.

This has worked really well for us.

So you boost every time you switch the light on? Isn't that a bit OTT? Can't remember the last time we used boost

[beddows_s]

This might be for a slightly different unit (Plus B) however the below should help your sparky. 

 

Available here: https://asset.eezybridge.com/nc/ba7b9546-29dd-40c4-87a7-885627281b87/479841.pdf

 

https://www.vent-axia.com/range/lo-carbon-sentinel-kinetic-plus-b#downloads

[Pocster]

I have this unit and was prepared to add a boost maybe linked to HA . What I found is the unit boosts really quickly automatically so it wasn’t necessary. If you shower then within 10 seconds it ramps up . I did make sure the vent pipe runs to bathrooms and en-suites were really short I.e mvhr unit is near too these .