Replacing bathroom extractor fan

erergwerg · Jan 23, 2022

Hi, I need to replace an old extractor fan in a house I rent out. The bathroom has a lot of black mould on the ceiling and I'm wanting to prevent this from happening again. A fan with a humidistat that turns on when it gets too humid sounds like a good idea but is it as easy as just replacing it?

The old fan is operated by the light switch and only comes on when the light is on so is not on a timer. Would the current electrical wiring be sufficient for a humidistat fan? I will be getting an electrician to replace it I just want to start looking at what kind of fan to get.

Any recommendations on good humidistat fans to get would be appreciated too (in from the UK) - there are some humidistat fans for around £40 with ok reviews but is it worth getting a more expensive one?

Thanks in advance.

littlespark · Jan 23, 2022

You would need a permanent live at the fan to run the humidistat. You’ll only have a switched live if it comes on with the lights.

It could be an easy job running an extra core for a live, or it could e an absolute mare of a job.

Get someone in to have a look.

123 · Jan 23, 2022

littlespark said:
You would need a permanent live at the fan to run the humidistat. You’ll only have a switched live if it comes on with the lights.

It could be an easy job running an extra core for a live, or it could e an absolute mare of a job.

Get someone in to have a look.

Agree with this, plus in doing this it will add the need for 30mA RCD protection for the circuit, if not already present

MJPD29 · Jan 23, 2022

Should be easily altered to make the live permanent to allow for the new fan.

telectrix · Jan 24, 2022

Matthewd29 said:
Should be easily altered to make the live permanent to allow for the new fan.

that would make the fan independent of the light, just reacting to excessive moisture. simple job, and does not entail repurposing the cpc as a live conductor.

. i like it.