Advice needed on extractor fan system

[dannyboy85]

Hi,

Before I ask anything at all, I am just going to start off with a disclaimer that I will not be undertaking any electrical work myself, I am just looking for general advice.

I've lived on the top floor of a purpose built 4 storey apartment block for a few years now. Up until a couple of months ago there have been constantly running extractor fans in my kitchen and bathrooms. I liked this. It keeps condensation down and takes away cooking smells etc.

They suddenly stopped working a couple of months ago and despite several attempts contacting the building management company, they simply refuse to acknowledge such a system is installed, and will not send anyone to repair them.

I have found a switch in the fuse box in the communal electric metre cupboard called "posivent supply", when I switch this on, the fans work but after a few hours the breaker trips. (This is not the fuse box for my flat, it is the one with the corridor and external lighting running from it).

I've just been up into my loft and there are 3 grey fan units with lots of tubes (pictures attached). The unit above my master bathroom (which I do not use anyway) does not suck any more, even when the other two are on so I've been able to find a switch to isolate this one (I will see if that stops the fuse from tripping).

I wondered if :

- someone could look at my photos and tell me what these are and how they work? Would they duct downwards and provide ventilation to the apartments below me too?

- what I should do if the fuse still trips after I've isolated the unit I suspect to be faulty?

- Can I get my own electrician to look at these? Or would they not want to touch them as technically they are not my property?

- as one of the units in one of the other flats adjacent to me could be tripping the fuse, could I have my own ones put in and run it from my own fuse box? Then connect to the existing ducting? Obviously this would mean me paying for the electricity myself - but I wouldn't mind that (as long as I'm not paying to ventilate all the flats below me!)


Finally, if the fuse no longer trips because I have isolated the faulty until, what solution cos there for my master bathroom? It's only used by the occasional guest to use the loo but there are no windows in that room so would like it to have some ventilation. (It's also the only place I can hang up duvet covers to dry, so I'd like it to have some).

So sorry about the long post and myriad of question, but absolutely any help of advice would be amazing! Thanks for reading if indeed you have.

 

[winston1]

Building management companies/local councils etc are not unknown to deny what they have. Contact them again only this time tell them your communal supply is faulty. Be there when they come to fix and show the fixer the tripped breaker and tell him/her what it supplies. Be sure to tell him/her that it trips after a few hours.
Out of interest what actually trips a MCB or RCD?

 

[oldbutnotdead]

Looks like a right shoddy installation, that scale of kit would probably only be serving your flat.
Presumably you're renting or leasehold owner- either way the landlord/building management should be maintaining that system (including periodic duct cleaning). Stop messing with the switchboard, get back onto them in writing (do NOT tell them you've been into the communal meter cupboard, a vindictive landlord could probably terminate your tenancy for that) and report the fault again.
If they fail to respond or repair the system then your local environmental health dept at the council is your next port of call-from the sound of it you have no openable windows in some rooms so mechanical air extraction is a requirement.
EDIT Good call from winston1 about reporting it as a communal supply/system failure

 

[sparkwright]

Presumably other flats won't have working fans, so this work does need doing, and needs doing correctly.

The management company are responsible and obliged to see to this work.

As mentioned, don't turn that circuit breaker on again, you don't know what might be at the end of it.

It certainly would make things easier if you were there to show the electrician/engineer.

It sounds like you may have to be forceful to get this work done.

 

[dannyboy85]

Thank you all for replying so far.

I'm afraid I have no idea whether it is an RCD or MCB, I'm not familiar with what those are.

I am in no way surprised that it is a shoddy installation; it is a fairly modern building built by one of the large property companies (I shan't go into names!).

I am the leasehold owner, and it is a private property. Nothing to do with the council or local authority.

I am perfectly entitled to enter the meter cupboard as this is where my electricity meter is. (I have a key to it for that purpose). But I won't tell anyone that I have been pressing a switch in there!

I shan't touch that switch again though. (Although there has been another residing doing this too as I've noticed it switching on at other times)

Anyway the "good" news is that since my last post (just after I isolated the fan above my main bathroom) the fuse has not tripped again.

I guess it must mean that unit has an electrical fault, and I will have to harass the property management co. into repairing it. (Wish me luck).

Until they do, I at least have working extraction in my ensuite and kitchen where I need it most.

 

[SimonH2]

I'm surprised that they are run off the communal supply - as it's apparently a small unit servicing only your flat, I'd have thought they'd have connected it to your supply.
Perhaps someone was thinking that since there are multiple units up there, it might cause confusion with different units on different supplies.
I agree with oldbutnotdead - it's a right bodge of an install, but about what you can expect these days where jobs are won on the basis of who will cut the most corners, err, I mean quote the lowest price
it may be a private head freeholder, but if something like that isn't working, then it's within the remit of the council environmental health dept. But TBH, given the dire state of so much rented stock (hence bigger issues to spend their limited resources on), I doubt they'd be that interested in it.
I own a leasehold flat, and we generally just get one with repairs and split the cost between us - with the agreement of the head freeholder. In reality, he'd be quite happy to hand over the management co to us, but when it's come up, not enough have been interested in taking it on. The alternative to doing it yourself, is that the freeholder gets someone in, adds a markup, and you end up paying more for a possibly lower quality job.
BTW, it looks like what you have is mechanical ventilation with heat recovery. A fan constantly sucks warm moist air out of the room and extracts it to outside. At the same time, it draws in fresh air from outside and blows it into the rooms. Inside the unit is a heat exchanger that uses the heat from the extract air to heat the incoming air - and so it's not constantly sucking as much of your heat out (you still lose a little as they aren't 100% efficient. You can see Passivent's website here, I can't see the model number in the first picture - if you get that you should be able to find it on their site. TBH, I'm slightly surprised to see these units fitted - don't know about this company, but in general the systems are "quite expensive" for what they are, and I wouldn't have expected a developer to have spent that unless forced to.

 

[SUNRAY]

TBH, I'm slightly surprised to see these units fitted - don't know about this company, but in general the systems are "quite expensive" for what they are, and I wouldn't have expected a developer to have spent that unless forced to.

But they are better quality than some of the cheaper versions and used in higher end developments/commercial.
But that is NOT a high end installation.

 

[oldbutnotdead]

And there was me thinking when you paid a management charge and ground rent that you actually got some maintenance done on the fabric of the building...I rent a house out, if the extractor fan stops working then its up to me as landlord to fix it at no charge to the tenant (unless the tenant has knackered it by stuffing insulation into it or similar)....yes if SimonH2's description of the finances is correct then probably best to get someone in yourself (with freeholders agreement of course)

 

[SUNRAY]

And there was me thinking when you paid a management charge and ground rent that you actually got some maintenance done on the fabric of the building...I rent a house out, if the extractor fan stops working then its up to me as landlord to fix it at no charge to the tenant (unless the tenant has knackered it by stuffing insulation into it or similar)....yes if SimonH2's description of the finances is correct then probably best to get someone in yourself (with freeholders agreement of course)

It's hard to know where the line is sometimes, As a buy to let leaseholder myself I wouldn't expect the freeholder to get involved with any of the services within my flats [so far I've replaced all of the switches and sockets at least twice between tenants] but anything powered from the landlords board is a no-no AFAIC, however I have replaced the windows in all of the properties as I wasn't prepared to leave my tenants with the rotting wooden frames that were in place.

In your situation, with less than ideal response from your landlord, I'd probably badger them by phone for a while, then and ask permission to get someone in.

 

[EFLImpudence]

Then send them the bill.

 

[John D v2.0]

To be fair to whoever designed the system it's not quite as shoddy as it looks (but not far off!), the flexible hose has all been stretched out fully which is an important thing to do, also insulated duct has been used presumably on the extract side, also suspending on elastic is a good technique for reducing vibration, albeit rather heath Robinson.
Gold standard would have been rigid ducting over most of the length and both the duct and unit supported correctly but you can't have it all.
If it really is a heat recovery, it might simply be the drain is blocked and the unit is filling with water and tripping the RCD.
Can we see the thing that is tripping, does it have a test button on it and say 30mA on it?

 

[dannyboy85]

Hi,

Thanks again to everyone who has replied. Really appreciate it.

@SimonH2 thanks for the explanation. I couldn't get close enough to get a good shot of the model number on the label as the loft isn't fully boarded - but I'll try again; I do want to know what the model is. You have helped my clarify what they're doing though. I've found out there are also vents which (quite gently) blow air into the room (albeit some previous owner seemed to have covered the "blows into the room" vent by putting duct tape over one of them - which I have now removed. I assume this was a case of "why is this thing blowing cold air into my kitchen").

I would imagine this system was fitted when the property was built, rather than being retrofitted, meaning they're going to be ~14 years old. I've no idea why they would have gone to the expense of installing such a complicated system when the normal extractors that come on with the light switch in the bathrooms would probably be sufficient?


For clarification there are three of those grey units in my loft with separate switches:
1. Above my ensuite - this sucks air up above my shower enclosure and blows it out further over in the room (this one is currently working)
2. Above my kitchen - sucks air above the hob, and blows out in the corner in the ceiling (also working)
3. Above my master bathroom - this only has a sucking vent (that I can see), and this is the one I have had to turn off in order for the whole lot not to trip out


The whole lot is definitely powered from the communal supply. I once switched off the supply to my flat entirely and the extractors remained working.

The remaining two fans have been running continually since Friday now - so it's certainly my master bathroom unit that's causing the fault.

@oldbutnotdead - yes, I also assumed that paying a ground rent and maintenance fee meant getting repairs of this nature done. Seems it is not that simple!

@SUNRAY thanks for the suggestion, I'm guessing if they're saying "we're not responsible for this", then they can't deny me permission to fix them myself (they can't have it both ways!). Their exact words were "The only vents within the block that I am aware of are the extractor fan pipe and this is something demised to each apartment and therefore not a communal issue."

I will of course contact them again now that I am armed with some extra information.

@John D v2.0 - I assume it was just installed by general contractors rather than specialists. I had assumed that the reason they're hanging like that was to stop vibration sounds from the ceiling. As long as it's doing its job to a reasonable extent, I cannot complain too much! I'll get a photo of the breaker that is tripping. While we're here, why is it best to stretch the hose out fully rather than shorten it to the correct length?


I'm fairly certain that the other upstairs flats also have these in their lofts too (with the electricity supply being taken from the same place) - but I wonder what would give extraction to the flats on lower floors? I previously assumed the units in the lofts also served the floors below, but you're right, I don't think they would be powerful enough to serve 4 flats in total?

 

[SimonH2]

Hoses should be fully stretched out to give a smooth interior wall and maximise airflow. They should also be cut down to length - I've seem installations where they couldn't be ar*ed and just snaked a full length back and forth across the attic
Thete are low profile units made for (eg) flats that don't have an attic. Also units that fit through thecwall just like an extractor fan.
BTW, the units should have filters in that will need cleaning/changing. After 14 years, they are likely to be "a bit clogged".

 

[John D v2.0]

so they are all single room heat recovery fans. It's a sensible idea and the reason they get installed in new builds is you have to get an overall score for efficiency with houses, and you can choose from insulation, heat recovery fans, heat recovery from the waste water, water efficiency, boiler/heat pump, glazing etc. If you find insulation is expensive for whatever reason or you want massive windows you can chuck in some of those units and it boosts your score a bit.

The master bedroom should have a supply too, but it may possibly be in the hallway or some other room. For whole house units the idea is extract in the wet rooms (ensuite, shower, toilet, kitchen, utility) and supply into the habitable rooms (bedroom, lounge, dining) so they might have taken a leaf out of that book. Another option is a combined supply/extract terminal which would try to blow/suck the air in opposite directions.

 

[dannyboy85]

Thank you all who have replied.

If nothing else, it's been good to learn about the system itself! I've got to say I'm really pleased with the job it's doing whilst it works.... Especially in my ensuite after having a shower. There's much less condensation on the window and when I buy my own freehold house, I'd like to have a similar system fitted!

I can't find any other supply vents anywhere else in the apartment. Just 2x in the ensuite, 2x in the kitchen and 1x in the main bathroom (where that's sending it's "fresh air supply" god only knows. (If that unit was working that is!)).

@John D v2.0 as promised please see attached picture of the fuse box supplying the units ...not sure if that tells you anything!

As it happens there was an electrician onsite when I arrive home from work... Apparently the TV aerial system was not working and he fixed that. I was not aware of that problem as the previous owner of my flat installed their own aerial in the loft which my TVs use.

I was going to ask him about the Passivent system but I don't think he would have known anything about it. I suppose it's nice to know that there is at least some maintenance that the management company are prepared to take up!