Manrose 1230 In-Line Backdraught Shutter – 100mm (4 Inch)

Stop cold draughts and improve your home’s energy efficiency with the genuine Manrose 1230. This high-quality backdraught shutter is a must-have accessory for any 4" (100mm) extractor fan or ducting system. It features a reliable internal damper with a single-spring mechanism to ensure your ventilation works in one direction only.

• Block Cold Air: Prevents wind and cold breezes from blowing back into your bathroom, kitchen, or utility room when the fan is not in use.
• Energy Efficient: By sealing your ductwork against outdoor air, it helps retain heat within your home and reduces energy bills.
• Pest Protection: Acts as a physical barrier to prevent insects and debris from entering your property through the ventilation duct.
• Silent & Reliable: The integrated single spring ensures the flaps stay shut even in windy conditions, preventing the "clattering" noise often found with gravity-only shutters.

Installation Instructions:

• The Manrose 1230 is designed for easy, versatile installation and requires no electrical wiring.
• Placement: This shutter can be installed in two ways:
• In-Line: Push it directly into a section of 100mm (4") rigid or flexible ducting.
• On-Spigot: Mount it directly onto the rear spigot of a 4" extractor fan
• Spring Positioning: Check that the single spring is correctly seated to keep the two flaps closed.
• Secure: If using flexible ducting, secure the connection with a duct clamp or high-quality duct tape to ensure an airtight seal.
• Test: Turn on your fan to confirm the air pressure easily opens the flaps, and watch them snap shut via the spring when the fan is turned off.