Topic: JempVent - Greenhouse vent opener - OIL

[mikey]

Hi all,

advice please ... have just erected and re-glazed a 6'x6' Greenhouse (free from my Son)

A Jempvent unit is fitted to open the roof vent ... but it is not operating.
If I understand the principle correctly, the oil in the cylinder expands as temperature rises and this pushes the piston 'out' which in turn opens the roof vent.

My question .... what type of oil is used  ???
is it 'any light weight oil' like 3 in 1 or special stuff

I would prefer to fix the damaged unit if possible, rather than throwing and spending +/- £30 on a new one

thanks
Mikey

[Tee Gee]

As I understand it it is not oil but wax!

What type I do not know I have been meaning to have a look at one of mine that is not working :-[

[laurieuk]

Some have oil and some wax but I do not think you can repair them in any way. I have had one that appeared to be not working but the rod had almost seized and when I freed that it worked well. They used to say with the early ones that you could not leave them in an un heated greenhouse during the winter but I found some still in working order that were in a derelict greenhouse with no glass and had been so for several years.

[Two Choices]

Don't know this specific type but all the ones I've seen are 'sealed units'. Worth a drop if 3 in 1 or plus gas and wait a day to see if it is seized before buying a new one though.

[Marymary]

i did see somewhere [sorry can't remember where] replacement wax cylinders.

[laurieuk]

Replacement units are listed at  https://www.parasene.com/vshop/details.asp?prodID=428  I am not sure if there are different models but I think they are all the same.

[janet h 1948]

I think I read on a message board last year that someone was having the same problem. The advise given was to put it in the freezer.