Circa. 2006 Bayliss changed the design of their ventilation system so that the piston can be removed, making the mechanism much simpler and more cost effective to maintain. I you purchased your greenhouse before this time then you will probably need this mechanism to replace the old.
This can be easily figured out by loosening the M6 bolt on the lower fixing block. If the piston can be easily slid out then you have the new design and only need to purchase the replacement piston.
If your piston cannot be removed because the fixing block is too tight around the piston, then you have an old style mechanism and need to replace it with this new design.
Our unique full length ridge ventilation of our structures has been designed to work specifically with the Bayliss automatic opening system.
They require no electricity to operate relying simply on the contraction and expansion of wax to open and close the greenhouse vents. The warmth of the greenhouse interior causes the wax to expand and push the vent open. Similarly as the greenhouse cools the wax contracts and vents close.
All our greenhouses have these fitted to the ridge vents as standard. The autovents will operate efficiently for a number of years but, like any moving part, will need replacing over the extensive life of the greenhouse. Such an important greenhouse accessory is held in stock and are simple to replace.
If you are unsure as to which vent you have, please get in touch with us. One of our team will be happy to help.