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Replacement filter set

GermGuardian Filter B – FLT4825 replacement filter

Filter B (FLT4825) fits GermGuardian AC4300, GermGuardian AC4820, GermGuardian AC4825 and 5 more models according to the cited GermGuardian source.

Official manufacturer Filter B FLT4825 Check official GermGuardian availability Non-affiliate link to the cited official product page.
Marketplace search Check eBay prices for FLT4825 Sponsored eBay links. We may earn a commission from qualifying purchases.

Quick fit check

Filter B fit and replacement facts

Part numberFLT4825
Compatible models8
Filter roleReplacement filter set

The cited page states that FLT22CB4 carbon pre-filters can be replaced every 2 to 3 months to extend filter life; it does not state a replacement interval for FLT4825.

Compatible GermGuardian models

Follow a model link for its complete primary, optional, specialty, and alternative filter list.

Model Filter Part number Role Source Marketplace
GermGuardian AC4300 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian AC4820 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian AC4825 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian AC4850PT Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian AC4870 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian AC4880 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian AC4900 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices
GermGuardian CDAP4500 Filter B FLT4825 Replacement filter set Guardian Technologies GermGuardian FLT4825 - Filter B Check prices

Buying checklist

What to check in a filter listing

Confirm that the listing names part FLT4825 and one of the compatible models: GermGuardian AC4300, GermGuardian AC4820, GermGuardian AC4825 and 5 more models. Similar-looking filters are not proof of fit.

Decide whether you want an OEM or aftermarket filter, then compare the included pieces, product photos, seller details, delivery estimate, and total price.

Care guidance

Replacement schedule

The cited page states that FLT22CB4 carbon pre-filters can be replaced every 2 to 3 months to extend filter life; it does not state a replacement interval for FLT4825.

Usage conditions can affect service life. Follow the cited manufacturer guidance for this part.

Compare compatible options

These filters share at least one officially cited model within the same brand, but may serve a different primary or optional role. Check each part page before buying.

Frequently asked questions

How often should I replace the GermGuardian Filter B (FLT4825)?

The cited page states that FLT22CB4 carbon pre-filters can be replaced every 2 to 3 months to extend filter life; it does not state a replacement interval for FLT4825.

Which GermGuardian models use the Filter B FLT4825?

According to the official GermGuardian product page, Filter B (FLT4825) fits GermGuardian AC4300, GermGuardian AC4820, GermGuardian AC4825 and 5 more models. Verify the model label on your unit before ordering.

Do aftermarket FLT4825 filters work?

Marketplace listings may be from the manufacturer or a third party. Match the exact part number FLT4825, review the listing details, and verify the model label on your unit before buying.

Manufacturer source

Official Guardian Technologies product page identifies Filter B, SKU FLT4825, as compatible with models AC4300, AC4820, AC4825, AC4850PT, AC4870, AC4880, AC4900 and CDAP4500.

Guardian Technologies GermGuardian FLT4825 - Filter B

Source compatibility checked 2026-07-22. Recheck the listing and your purifier label before ordering.