Humidistat fan won't come on

[edwardxpx]

I have installed a humidistat + pullcord override extractor fan in my bathroom (Manrose). The fan works on the pullcord but it doesn't come on via the humidistat. I've adjusted it to the most sensitive setting and had the shower running but with no luck.
Are humidistats generally reliable? Should I persevere / repalce the fan / just go for a pullcord model?

 

[bongos]

Is it a large bathroom? Decent make humidstat?

Humidstats seem like a good idea but cheaper ones can be unreliable and many people just opt for a timed fan to gurantee bathroom extraction (also a timed fan helps to get rid of those unpleasant smells).

 

[edwardxpx]

Not a big bathroom, and a Manrose fan. I am inclined to go for pullcord simplicity.