The cylinder of the Bayliss Autovents is basically a strong metal tube that contains a mineral wax. This wax expands with heat and it is this expansion that enables the autovent to open your greenhouse roof vent when temperatures increase. When temperatures drop the wax shrinks, allowing the window to close with the assistance of a strong stainless steel spring. These cylinders are designed as a replacement part for your vent opener. So if your autovent stops working, have a look to see if any of the wax has leaked from the cylinder. If so, by fitting a new cylinder into the autovent your window should start to open again when temperatures increase.
Two Wests & Elliott (UK) - manufactures and suppliers of
greenhouses, greenhouse staging, fruit cages (netting and aluminium
tubing), a wide variety of gardening equipment and
accessories.
