ValloPlus 850 Filters

We stock filters for a wide range of Vallox models — from older series widely installed in Finland and across Northern Europe (e.g. Vallox 90 SE, 101 MV, 350 SE) to newer, digitally controlled ValloPlus units (e.g. ValloPlus 850 MV). The exact model name and airflow variant is shown on the front panel next to the digital display — this is the most reliable way to choose the right size filter.

Most Vallox and ValloPlus models come with the following filter set:

• Two G4-class filters — one for extract air, one for outdoor air
• One F7 (ePM1) class filter — for supply air

This differs from some other manufacturers who use M5 on the extract side — in Vallox's design, a simpler but more frequently replaced G4 filter does that job instead. This combination meets Finland's strict indoor air quality requirements for cold-climate housing, while keeping pressure drop across the heat exchanger low.

Vallox's digital controllers assess filter contamination based on one or two indicators:

• The number of operating hours elapsed
• On some models, the pressure difference across the filter

This is a useful reminder, but it's also worth checking the filter visually and assessing airflow manually, especially in the first year after a new unit is installed, when the actual rate of contamination isn't yet known.

No — filter dimensions within the ValloPlus range vary according to the unit's airflow class, so higher-performance models (e.g. ValloPlus 850) use larger filters than more compact residential variants. To ensure an exact fit, you need to refer to the specific model name and airflow variant shown on the front panel — the series name "ValloPlus" alone isn't enough to choose the correct size.

Yes, many Vallox models offer an activated carbon supply-air filter layer as an addition to the standard G4/F7 filtration — it helps absorb vehicle exhaust odours and urban pollution before the air enters the home. This is a popular choice for flats near busy streets, though such a filter generally needs to be replaced at a similar frequency to the standard one, as the carbon layer's absorption capacity also depletes over time.

Vallox systems use a three-filter setup to ensure optimal air quality and protect the system. Our replacement filter set includes two G4 filters and one F7 filter.

One G4 filter captures coarse particles from the extracted indoor air, protecting the system from dust and debris buildup. The second G4 acts as a pre-filter on the supply side, trapping larger particles such as insects and debris before they reach the main F7 filter. The F7 filter performs the greatest filtration function, capturing finer particles such as dust, pollen, and allergens, thereby improving indoor air quality.

This combination helps extend the system’s lifespan and maintain efficient performance.