Replacing a bathroom extractor fan

[sleepyhead]

Is this a job I can do myself? I'm reasonably experienced with very basic household electrics (eg replacing light fixtures and wall sockets).

The existing fan is ceiling mounted, noisy, old (potentially as old as the building c2001), but otherwise working - no mould or condensation issues.

It comes on with the light and I'm happy to continue with that if I can get something quieter.

We're in a second floor flat, bathroom is internal.

The box for the fan is considerably bigger than modern units - almost shoebox size. Will the ducting etc otherwise be standard? Anything else I'd need to buy other than the new unit?

Any recommendations for fans would be great too

Just found my existing model: www.greenwood.co.uk/product/26/422/centrifugal-100mm-bathroom-extractor-fan-with-two-room-ventilation-option.html

Don't know why it's a 2 room model - it's definitely only venting one room . I guess it was maybe a job lot since some of the flats also have ensuites.

100mm is typical for a ducted inline fan. Can you hide the new one above the ceiling or in a cupboard, or will it be on show?

Is it wired for an overrun timer (four wires)?

Or just three wires?

I'm fine with it being on show. I want it in the same position as the current one for simplicity. Not sure about above the ceiling - we have neighbours above so certainly can't go for loft fitting or anything like that.

According to the installation instructions online, you can wire it with an overrun timer.

This all may be moot however, as I tried to get the cover off to check the wiring and can't for the life of me see how to get it off . There's a single screw in the bottom which screams "undo me", but it just goes round and round....

The instructions aren't helpful in this regard "remove cover", yeah I'd like to do that. How about a picture or continue that sentence with the word "by..."

www.greenwood.co.uk/uploads/docs/461.pdf

the timer depends on the extra wire having been included from the switch or ceiling lighting rose. So if the old one didn't have a timer, it would be extra work if you want one that does.

The more powerful and quiet modern ones look something like this and are intended to be hidden away.

You could fit another Greenwood, but more modern designs with a ball-bearing motor are available though they may not look so good.

Look for the air throughput in cubic metres per hour. Cheap bathroom fans are usually 80cu.m which is not enough. Also look at the noise level in db (I presume you will want one no noisier than your old one)

Plastic covers sometimes have a "quarter-turn and pull" screw head, but if you ring the makers they should tell you. Also ask for their current brochure. There should be a wide isolating switch high up on the wall or outside the bathroom door to cut power before you start.

it looks like your old one has a performance of only about 100cu.m nominal (the length of the duct will reduce throughput) so this very quiet and inexpensive one would match that. However if you find your bathroom steamy and slow to clear, look for a more powerful and ugly one, or get a Permanent Live fitted and use a run-on timer model. With low noise and power use, it will not matter that it runs longer.

Browse the category, looking at cu.m and db figures, and see what you fancy.

If by any chance your duct is bigger than 100mm, you can get a bigger fan, which will be better.

Thanks, that's very helpful.

I contacted Greenwood who confirmed that the bottom screw is what's holding the case on and it should unscrew. I'll try a quarter turn before I reach for the pliers.