Extractor Fan Running Continuously - Broken Timer?

[EwanWhoseArmy]

Hi, I have two Primeline PEF4020 extractor fans - Fan 1 has not worked since I moved in a few months ago, and Fan 2 would come on with the light, and then after the light turned off, it ran on timer for a minute.

To test if Fan 1 had something wrong with the circuit board or the fan itself, I swapped the circuit boards of both fans with each other. Neither fans worked with this configuration, so I believe both Fan 1's circuit board and the fan itself are dead. That's fine, I'm happy to buy a quieter one anyway.

The problem started when I put the original circuit board back into Fan 2 - Now the fan is always on, regardless of if the light is on or off. After reading some things on this forum, I swapped the Permanent Live and the Switched Live which caused the fan to turn on and off at the same time as the light.

So question 1 - Does this mean that the timer component somehow got damaged when I swapped the circuit boards and now it continuously runs (when the PL and the SL are in the correct places)?
Edit: I just had a thought that even if the timer had died, would that justify the fact the fan runs even when the light is off?

Question 2 - Is it ok to leave the PL and SL swapped? To be honest I don't mind having the fan only come on with the light if it saves me having to buy another fan, so I just want to make sure it couldn't potentially cause problems.

 

[flameport]

1 - certainly possible.
2 - if no timer is required, remove the timer board completely and just connect the fan motor wires to L&N using a terminal block.

 

[EwanWhoseArmy]

Probably a dumb question, but does that mean the entire circuit board is there purely for the timer functionality?

Also because I don't have a terminal block lying around, are you implying there is a problem with just leaving the board with the L & SL wires swapped? Or is it simply that a terminal block is a neater solution?

 

[flameport]

the entire circuit board is there purely for the timer functionality?

Yes.
The versions with no timer are the same fan, just with no circuit board.

Leaving the circuit board installed will waste energy as they have a large resistor on them which gets hot, wasting away the energy as heat.
The circuit board is usually darkened by the heat after being in use for a few years.

Terminal strip is cheap and plentiful https://www.toolstation.com/connector-strip/p88321
and also removes the possibility of further failure of the already damaged electronics.

 

[EwanWhoseArmy]

Oh that's great to know, thanks for the advice! You're right as both of the circuit boards are darkened. Only one failed so far, but probably for the other it's only a matter of time.

Does it matter which fan motor wire I connect to either the L or N? Both motor wires are the same colour so I would assume it doesn't make a difference, but I thought it's best to ask.

As for the now spare SL wire with nowhere to go, I guess that's best to either put in a terminal block going nowhere (or cover up the end with some electrical insulating tape)

 

[flameport]

Doesn't matter, it an AC motor.

Spare wires in a terminal block, tape dries out and falls off.

 

[EFLImpudence]

As for the now spare SL wire with nowhere to go,

Spare PL?

 

[EwanWhoseArmy]

Doesn't matter, it an AC motor.

Spare wires in a terminal block, tape dries out and falls off.

Great, thanks! And fair point about the tape.

Spare PL?

Spare SL - Sorry I just meant if I only need to connect the L&N (since I don't want the timer anyway) then the SL is left loose/spare.

 

[flameport]

Fan connects to SL and N, L is spare.
If you connect to N&L it will run continuously.

 

[EwanWhoseArmy]

Fan connects to SL and N, L is spare.
If you connect to N&L it will run continuously.

Sorry, yes of course, you're right L is the spare. I've got it it up and running now, and it's definitely SL & N connected to the motor because the fan only turns on with the light. Again, thanks for all the help, I appreciate it.

 

[EwanWhoseArmy]

@flameport I have a new but slightly related question - I'm looking at wiring up an extractor fan to a UK mains plug. I believe it shouldn't be too different from what you advised with a terminal block since I don't want a timer - Just connect the Neutral of the plug to Neutral terminal in the fan, and the Live of the plug to the Switched Live terminal of the fan. Is that right, or have I missed something?

I've read other posts on here that point out the need for a 3A fuse which sounds fair enough. Then others saying you need to connect the L & SL terminals of the fan for it to work, but surely just connecting the L of the plug to the SL of the fan should be enough?

I'm sorry if this should've been a separate post but you were so quick to reply last time and very helpful, so I thought I'd tack it on to the end of here.

*By the way, I should say the fan is not for a bathroom. At a friend's house they got rid of their tumble dryer, leaving a hole in the wall to the outside from their kitchen which is currently just blocked up with a towel. Therefore there's no convenient mains cable ready to go into it, but plugging it is isn't a problem if I've wired it up to a plug, so I thought I'd make use of a pre-existing hole in the wall.
Sidenote - while I was in Italy I noticed some bathrooms have extractor fans just with a mains plug connected to a socket because I guess they're allowed sockets in bathrooms there, so I took a bit of inspiration from seeing this.

 

[RandomGrinch]

Then others saying you need to connect the L & SL terminals of the fan for it to work,

You have sort of missed something

On your fan, you had a timer board, that you have removed - the PCB was completely bypassed, with the connections made directly to the fan.

If you had a new fan with an operating PCB, you may not want to remove the PCB.
In that case, you would need to connect both L and Ls terminals together, for the fan to work.

However, just buy a simple fan without a timer - you will only have an L and N to connect up - simples!

Some adaption on the inside of the fan case may be needed, to provide a suitable cord grip for the use of a flex and plug.

 

[EwanWhoseArmy]

Ah ok, that makes sense then. Would it do the trick just to have an extra bit of wire screwed into the L & Ls terminals to connect them?

As for buying a simple fan without a timer - That could certainly be a bit less faff, I'm just seeing what I can find on Facebook Marketplace. For example I found an Envirovent Silent 100 for less than a tenner. It's probably overkill for what I need, but at that price I wouldn't mind having to choose between connecting the L & Ls, or removing the PCB altogether

Yeah I'm sure that I'll have to adapt things inside the case since it's not designed for a plug, but it shouldn't be too difficult.

Thanks for your quick and clear response by the way!

 

[EwanWhoseArmy]

Although it's not really necessary, I thought I'd add some closure to my extension of this post in case it's useful information for anyone in the future:

In the end I bought an Envirovent 100-S for £8 from Facebook Marketplace (100 = mm diameter, S = standard, i.e. basic functionality, no timer or anything, so perfect for my needs). I bought a couple of meters of 0.75mm2 flex and wired the Live and Neutral to the corresponding terminals of both the plug and the extractor fan and done!
I also switched out the 13A fuse that came with the plug for a 3A one because that seems to be the general consensus from similar situations to mine that I've seen in forums (but I'm happy to receive advice on that if it turns out 3A is not appropriate)

The placement in the kitchen is obviously not ideal, and at 95m3/h the power is probably not the best for a kitchen, but for less than £19 I've managed to re-purpose a hole in the wall that was originally for a tumble dryer!