Odd new bathroom extractor fan noise - diagnosis?

[joebongo]

Hi,

We have a bathroom ceiling vent above the shower via flexi-duct to an in-line Manrose extractor fan unit which sits in the loft. It was fitted in Spring 2012.

Today we noticed a low volume and low-pitch bub-bub-bub noise along with the normal extractor fan noise. It sounds like a motorbike engine noise in the far distance. It isn't 100% consistent and may stop for a second or so and then returns.

We can stop the noise by restricting the flow of air up the vent. I found this out when checking if the fan was still sucking by seeing if a piece of toilet paper would stick to the ceiling vent grille, which it did and it also stopped the noise.

So any ideas or experience of such a noise and how to get it sorted?

Many thanks,

Joe

 

[JohnW2]

Today we noticed a low volume and low-pitch bub-bub-bub noise along with the normal extractor fan noise. It sounds like a motorbike engine noise in the far distance. It isn't 100% consistent and may stop for a second or so and then returns. ... We can stop the noise by restricting the flow of air up the vent. I found this out when checking if the fan was still sucking by seeing if a piece of toilet paper would stick to the ceiling vent grille, which it did and it also stopped the noise.

You really need to get access to the fan and it's outlet vent to see if something (even if just dust/muck) has got sucked into its impeller, or into the outlet vent/whatever (I've found the remnants of mice in in-line fans in my time!). If that's not the problem then it is, of course, possible that the fan is simply ill or dying.

Kind Regards, John

 

[joebongo]

Hi,

Consider this solved.

Having unclipped the hose that goes out to the exterior wall it was waterlogged. The rain had come in through the wall grille and settled in both the hose and the fan unit base.

Emptying and clearing, reattachment and test indicates noise back to normal.

Thanks for the reply,

Joe

 

[JohnW2]

Having unclipped the hose that goes out to the exterior wall it was waterlogged. The rain had come in through the wall grille and settled in both the hose and the fan unit base. Emptying and clearing, reattachment and test indicates noise back to normal. ... Thanks for the reply,

You're welcome. I suppose that when I talked of 'dust/muck', I should also have included water! I'm glad that the problem is solved. Ideally, the hose should have a bit of a 'fall' as it heads towards the wall grille, so that any water runs out.

Kind Regards, John