Flexit HRV Filters

Flexit HRV filters are exact-fit replacement filter sets for selected Flexit heat recovery units. Designed for a secure fit, these filters help maintain stable airflow, protect the heat exchanger, and support cleaner indoor air.

Our Flexit-compatible filters are made in Lithuania and supplied as practical two-filter sets for supply and extract air. Browse all HRV / recuperator filters, see delivery & shipping, or contact us if you need help choosing the right set.

Flexit filters for UNI, Nordic, K2, C2 and other series

This category includes replacement filter sets for popular Flexit units such as UNI 2, UNI 3, Nordic S4, Nordic CL2/CL3/CL4, K2.1, Flexit C2, EcoNordic, S3R / K3R, S4R / S6R / S7R, and L7X / S7X (VG700). Always match the exact model and filter dimensions before ordering.

Two-filter sets for supply and extract air

Each set includes two filters: one for supply air and one for extract air. Correctly fitted filters help reduce bypass air, support balanced airflow, and keep the ventilation system cleaner over time.

Filter classes and exact dimensions

Depending on the model, Flexit replacement sets may include efficient filtration options such as F7 + F7. Verified examples on Filters1.eu include dimensions such as 293×226×48 mm for Flexit C2, 419×192×31 mm for UNI 3, and 290×234×48 mm for Nordic CL2/CL3/CL4. Before ordering, compare your old filters or check the unit label to confirm the correct version and size.

How often should you replace Flexit HRV filters?

A practical replacement interval is 2–3 times per year. In dusty areas or where outdoor air quality is poorer, more frequent replacement may help maintain cleaner air and stable airflow.

Shipping across Europe

Filters1.eu ships across Europe. Shipping options and delivery cost are calculated at checkout. If you are unsure which Flexit filter set you need, contact us with your unit model or a photo of the unit plate and we’ll help you match the correct set.