fan keeps stopping

[janeyo]

I have a decent sized polycarb greenhouse. It has a fan in the roof which goes off when it gets too hot, a solar paneled thingie.
It works fine for 9 months of the year when it is cold - and has been known to come on in the wintery sun of february, but as soon as we get any proper heat it stops. OH cleans it and then it works for another week or so. It is drivng me bonkers now.

What do you all have for ventilation in your polycarbs? It was unbearable in there today and it's only mid-may. It has a slide-up and down window at the back and one fan in the roof.

Thanks

[womble]

I don't know anything about your fan, but what sprung out at me is that it stops when it gets hot.
Metal expands, if there was something in your fan that expanded to stop it turning round, that would do it.
If you can, watch it in the morning and see if it is running normally, try to watch it if it is going to get hot (weather) and keep a very close eye on the fan. It may possibly slow down, or you may hear something dragging.