Harrisons i-vent filter replacement, fitted and checked properly, not just swapped and left. If the filter's overdue or you're not sure what it takes, this is what a proper replacement involves.
Is this you?
The filter, properly explained
Harrisons i-vent systems generally run an F7 or F8 grade filter, roughly 295 x 295mm. To maintain the manufacturer warranty, the filter needs changing every 12 months. Some suppliers list 12 to 24 months depending on air quality, but sticking to the 12-month mark protects the warranty regardless. Buying a filter online and fitting it yourself will get dust out of the airstream. It won't tell you whether the fan's clogged, the ducting's damaged, or the system's actually pressurising the house the way it should.
What a full service covers
Filter replacement with the correct grade, roof cavity intake check, fan unit clean, duct inspection, diffuser cleaning, and a flow test to confirm real performance, not just a fresh filter smell.
Where we draw the line
MiHT services, cleans, and maintains Harrisons i-vent systems. No installation, no manufacturer ties, no push toward replacing a system that just needs looking after.
