bathroom fan

[ade2k]

Hi all
Three years ago I installed a fan in my bathroom thin has a timer which runs on for 15mins , no problems with that but the fan was not powerful to remove the condensation from the room and I got a small patch of mould on my wall.

So I brought a more powerful fan which pulls twice as much air out of the room but I have now noticed that now when I turn on the kitchen light the fan starts running for 15 mins. This never happened before and the fan is wired up exactly the same way. How can this be ?

 

[wingcoax]

Dare i say it? Double check your wiring. The kitchen switch is obviously giving the fan a supply.

 

[ericmark]

Many years ago I bought a book on DIY car projects which used standard chips like the 74121 to do things like auto start windscreen wipers when it rained.

I built a few and with car engine stopped they worked A1. But once one started the engine it was a very different story.

The word is EMC but most of use just call in interference. The humidity control was know for this problem.

The question is does the fan not comply or does the kitchen light not comply? I have as a radio amateur come to hate the florescent lamp because of the interference it produces.

The bathroom fan often is controlled by the light. Where the fan is an extra this is no problem. However where building regulations require a fan often the light controlled fan does not fit the criteria. Most bathrooms have windows so the user may not switch on the light. The easy way is a pneumatic switch this requires the user to press the button but is simple and works.

Once you more off lighting supply to non lighting supply then likely it will work OK.

So step one temporary fit a 13A plug and see if kitchen lamp still sets if off.

Assuming it does not then step two is fit a double pole light switch and FCU so it is no longer fed from the lights. Now since although same light switch the circuits are independent so you can add a pneumatic switch in parallel with light switch. Now you can switch it on with out the lights likely the old one would have done the job.

Rules for loo and bathroom are not the same. It's all in one of the Part's on building regulations I think Part F!