Wolf CWL-300/400 Filters

Yes, ordering a full year's worth of CWL filter sets in one purchase is common, particularly for households already managing a paired Wolf heating system on a similar service schedule. Multi-set orders are typically priced lower per filter than buying individually.

No — filter dimensions scale with unit capacity across the CWL range, so a CWL-300 takes a smaller filter than larger CWL-400 or CWL-2000 models. Confirm your exact CWL variant on the front panel label before ordering, since the series name alone doesn't guarantee a matching size.

The ventilation and heating functions operate independently in terms of filter maintenance, but combined Wolf systems often run ventilation more consistently to support overall climate control, so it's worth checking CWL filters on the shorter end of the standard 3–6 month interval.

CWL units typically use a two-stage setup on the supply side, consistent with German indoor air quality guidance:

• M5 coarse filter
• F7 (ePM1) fine filter

Both grades fit the same filter housing without modification.

We supply filters for Wolf's CWL series, the German manufacturer's primary residential MVHR range, often installed alongside Wolf heating systems. The CWL model variant is printed on the unit's front panel label.