Published · Updated · By the MVHR Expert engineering team
Before you start
- Find your unit's make and model on its label or in the manual
- Buy the correct filters — most units use a coarse G4 and a finer F7, but this varies
- Have a bag ready for the old filters; they will be dusty
- Only do this if the filters are reachable without tools or ladders beyond your comfort — otherwise book a service
Steps
- Turn the unit off at the isolator or fused spur.
- Open the filter access panel or front cover as described in the manual.
- Note the position and orientation of each filter before removing it.
- Slide out the old filters and bag them immediately.
- Wipe any loose dust from the filter housing with a dry cloth. Do not use water.
- Fit the new filters in the same orientation, following any airflow arrows.
- Refit the cover so that it seals properly — a poor seal lets air bypass the filters.
- Switch the unit back on and reset the filter timer or warning light.
When to call a professional
If the filters are very dirty, if you notice dust inside the heat exchanger, or if you have never had the system serviced, a professional service is worth having. Filters are only one part of what keeps an MVHR system working.