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.
If purchasing a replacement piston firstly check that piston rod is located correctly in the hole in the top block. The rod is designed to disengage in windy conditions and may need to be reset manually. If the piston has stopped working, you may be able the slide the piston assembly out from the bottom block by loosening the m6 bolt in the block.
If you purchased your greenhouse before 2010, you will probably need the improved 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.
Old type (Square Blocks) with fixed piston New type with replaceable 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 each complete unit with the new design. 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.
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 several 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.