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Home > Help > EFW TV > Domus / Silavent Mayfair Backboxes Explained

Domus / Silavent Mayfair Backboxes Explained

Video Transcript

Today, we are looking at the highly regarded Mayfair range from Domus.

The Mayfair range uses a back box mounting frame which allows the fan to be easily fitted and removed without the need to re-wire as the power is wired to the back-box and connected through this terminal to the fan unit.

There are two back boxes to choose from for the standard range; the flush mounting recessed back box MAY905B and the surface mounted MAY904A. 

Here we are using the popular MTD070B centrifugal unit with timer and the surface mounted MAY904A as an example.

When installing these units there is a little trick that you need to know.

On the rear of the fan unit there is a motor cover which keeps loft insulation a safe distance from the unit when mounting with a recessed back box.

However, When mounting with the surface mounted backbox, the motor cover stops the fan from being seated correctly.

Installers often mistakenly believe they have ordered the wrong backbox for the unit, however, this is not the case.

The motor cover simply needs to be removed. This is done by removing this screw and unclipping the cover from the two retaining clips.

The fan will now seat properly into the back box allowing the pins to be fully inserted into the power terminal and the back box itself becomes the cover for the motor.

This leaves you with the original motor cover to do with as you will- I suggest a pasta-for-one strainer!

Don't forget to check out the full range of Domus Mayfair fans including the stylish Mayfair Classics on

We’ll be back with some more Fansplaining soon.

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