Bayliss MK7 Autovent Replacement Cylinder

This mk7 autovent replacement cylinder is designed for use with Mk7 automatic greenhouse window openers. 

The standard tube is filled with wax that expands as temperatures rise, allowing greenhouse windows to open automatically. Opening begins between approximately 12°C and 24°C, depending on adjustment and conditions.

This replacement cylinder suits gardeners maintaining existing Mk7 systems and looking to replace a worn or failed unit. It fits directly into compatible Mk7 autovent mechanisms.

Standard Mk7 cylinder size
Temperature activation range approximately 12°C to 24°C

How The Mk7 Greenhouse Window Opener Cylinder Works

The mk7 cylinder reacts to temperature changes inside the greenhouse without power or wiring. Heat causes the wax to expand, moving the piston and opening the vent.

Adjustment of the opener determines when opening begins, usually from around 12°C up to approximately 24°C. This helps manage airflow during changing weather.

This process supports steady internal conditions for plant growth through automatic ventilation.

Replacement Cylinder For Greenhouse Vent Maintenance

Over time, wax cylinders can lose responsiveness due to age or repeated temperature cycles. Replacing the cylinder restores proper vent movement.

This mk7 autovent replacement cylinder supports continued use of existing greenhouse hardware without replacing the full opener.