Silavent Quadvent 750 - Smaller Box underneath is a mystery!

[JonjoRigby]

Hi,

I have a a Silavent Quadvent 750 ventilation system in my apartment, and it seems to work an absolute treat. However, under the box, and connected to the main Silavent box by a thick wire, there is a further smaller box with a black dial switch. The switch has two settings, 0 and 1. Choosing either setting doesn't seem to make any difference to the Silavent and how it operates. It doesn't turn it off when set to zero, and the power doesn't seem to increase when it's set to one.

Anyone any ideas as to what the smaller box does and what the settings 0 and 1 are for on the dial switch?

Many thanks

 

[littlespark]

Pics would help, Jonjo

 

[JonjoRigby]

Thanks for your reply, I've actually found out what it is now. It's a booster switch. When set to 1 it boosts the system when the bathroom lights are turned on.