Strange behaviour with Airflow Icon bathroom extractor fan

[rapidnailer07]

I have 4 bathrooms and each one has the same identical setup: Airflow iCON 30 extractor fan with the humidity + pull cord + timer control module (part number 72687103). All items were purchased within months of each other.

For over 2 years, all working fine and as expected. When the fans were triggered from the light switch or the pull cord or the humidity, the motor to spin the fan would immediately start (to be ultra clear, I'm not talking about the fan cover which has delayed opening).

Example video of how the fans would start up: link

However, recently I had a complete refurb of one of the bathrooms and the extractor fan was removed and set aside to allow the work to happen. The electrical wiring for the extractor fan was partially exposed due to the refurb work around it.

When the fan was reinstalled it started to behaviour strangely in that when the fan was triggered, the motor would take between 2 to 15 seconds to start up. Most of the time it was on the lower end but it was somewhat random. Example video on one of the long start up times: link.

The electrician has been round multiple times to investigate and try to resolve this with no luck. Electrician has checked:
1. Voltage across all the wires when the fan is both off and on - everything is normal by their opinion.
2. The electrician purchased a brand new extractor fan and module (exact same model like for like) and installed these (I can confirm these were new purchases) - this did not resolve the problem
3. I contacted Airflow about the problem as the unit was still under warranty. They sent out a complete new extractor fan and module (again, exact same model like for like) which they fully tested at their site before sending out to confirm it was operating correctly. When this arrived, the electrician installed both of these and it still did not resolve the problem.

Given this problem has occured with 3 different extractor fans+modules, it is unlikely to be those. However, the wiring has also been confirmed to be correct as the voltage is within the expected range in all scenarios.

Both me and the electrician are completely stumped. Electrician has said perhaps it is a change of design with Airflow and this is how the new fans work by design (although it doesn't explain why the original fan had this problem after the refurb but never had the issue before). Unfortunately the origianl fan has been disposed of so we don't have that any longer.

What could the issue possibly be?

[Someone-Else]

In neither video do the shutters open, must be normal then

You said it was tested and working before it was sent to you, there is your problem. They "tested" it, I suspect it was tested laying flat down, you didn't mount it flat down, so I have to ask, what happens if you take it down, wire it up and plug it in, while it's on a table. I checked, a lot of folk like the look, but say they don't open too well, or not at all, and do need cleaning

[rapidnailer07]

In neither video do the shutters open, must be normal then

Yep, normal behaviour. The covers have delayed opening, if I kept recording then it would have showed the covers opening but this post is nothing to do with the covers. It's about the fan motor which is what you hear in the video.

You said it was tested and working before it was sent to you, there is your problem. They "tested" it, I suspect it was tested laying flat down

I don't know how it was tested but I sent Airflow the video of 15 second delayed motor start and they acknowledged the problem and did their testing with this context in mind.

you didn't mount it flat down, so I have to ask, what happens if you take it down, wire it up and plug it in, while it's on a table.

It's designed to be wall or ceiling mounted and should work as normal in either orientation. It was working fine for 2 years when it was wall mounted so something is not right.

[Someone-Else]

That's as maybe, but what happens if you put YOURS on a flat table and try it?

[rapidnailer07]

That's as maybe, but what happens if you put YOURS on a flat table and try it?

I feel that's a very very long shot and given that the refurb company are unlikely to send out an electrician to "test it on a flat table" I don't think that's going to go anywhere.

Was kinda hoping that someone would post to say something like:
1. "ah yeah, that happened to me. That happens when XXX" or
2. "I bought one of these recently and mine does exactly that"

or anything else a bit more concrete like that.

[wine~o]

Is this the 12V (selv) version or mains ? if selv then I would suspect that a "soft start" transformer has been installed. Of course, I could be barking in the wrong forest...

[rapidnailer07]

Is this the 12V (selv) version or mains ? if selv then I would suspect that a "soft start" transformer has been installed. Of course, I could be barking in the wrong forest...

Mains powered. Was showing 246v which is within spec for mains powered.

[Someone-Else]

I am only trying to help, so what happens if YOU wire it as it should be and YOU put it on a flat table, then plug it in. (Think about it, it is the only thing that has not been done.)

[rapidnailer07]

I am only trying to help, so what happens if YOU wire it as it should be and YOU put it on a flat table, then plug it in. (Think about it, it is the only thing that has not been done.)

The original fan was working fine for 2 years wall mounted. Same fan after the refurb work finished now has the issue. As far as I'm concerned, there's no problem with the fan being wall mounted.

I'm not an electrician and don't feel comfortable doing the wiring myself, the existing wires wouldn't even allow it to reach a flat table. And even if I did somehow try this and it didn't have the start up lag, then it doesn't fix the actual issue of it working as it originally did in a wall mount orientation.

[Neelix]

I’d be looking at the neutrals

[aeromech3]

I had a problem with a new fan, on reporting to the Co. they sent me a replacement; on removing 1st one from the wall, I could then see a sticker notice in the duct which had become partly unstuck, but would pop up as the fan started, removed same and have a spare fan now!

[ericmark]

I would have wondered if by design if you had not said manufacturer says there is a fault. I have in last 10 years lived in three houses, one has a problem with mould in bathroom, other two did not, so I started to think why.

What I realised it was the chimney effect in the one house where the shower was in the bath, so there was a space both bottom and top of shower doors, the other houses one had no doors, it was a wet room, the other the door sealed at bottom, so the shower mist was not circulated throughout the room.

A shower fan above the shower will clearly remove the mist directly outside, but a fan in the wall will draw the mist out of the shower cubical dragging it through the room, so will cause whole room to get damp, not just shower area, so for the fan to start after one has finished with the shower would be better, one as not sucking the mist out of the shower cubical, and two not causing cold air to be dragged into shower while one is having the shower.

So a delayed start is in some ways good, however there is a problem with a humidistat that if they get too damp, they take an age to dry out, my dad's could take 2 hours before it switched off, hence the idea of kicking the fan off with a pulse from the light. But so many don't switch off unless the light has been switched off, and since my dad's shower was in his bedroom, wiring to lights was not a good idea.

We actually found more damp entering room from vent in roof, than the fan was taking out, so better to re-tile hole in roof and do away with the fan.

But this house the fan has failed, the plumber blocked the wall vent when he built the new shower, but no sign of mould, so not done anything to fix the fan or open up the vent, specially as outside we noted a bees nest in the vent.