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GermGuardian air purifier

GermGuardian AP3250 replacement filter

GermGuardian AP3250 has 2 primary replacement filter parts: FLT51CB4, FLT5100. Match the role and part number before ordering.

Official GermGuardian fit · checked

Same filter, other models

Other GermGuardian purifiers that use the same filters

Filter O Carbon Replacement Filters (4-Pack) FLT51CB4

Filter O FLT5100

Own more than one purifier? These models share the same official part number.

All compatible GermGuardian AP3250 filters

Primary filters are listed first. Specialty, optional, and alternative filters also fit, but you only need them if you want that feature.

Filter Part number Type Price
Filter O Carbon Replacement Filters (4-Pack) FLT51CB4 Replacement carbon pre-filter pack Check price
Filter O FLT5100 Replacement filter set Check price
Filter O PET PURE FLT5100PT Specialty replacement filter set Check price
Filter O SMOKE CLEAR FLT5100SM Specialty replacement filter set Check price
Filter O TOXIN CLEAR FLT5100VO Specialty replacement filter set Check price

Price links open sponsored eBay searches for the exact part number.

Official package contents

What's in the box

From the linked official GermGuardian product page. Marketplace packs can differ, so compare before you buy.

Filter O Carbon Replacement Filters (4-Pack) FLT51CB4

Before you order

How to buy the right GermGuardian AP3250 filter

  • Confirm the label on your purifier reads AP3250.
  • Make sure the listing names part FLT51CB4 and FLT5100, not just a similar-looking filter.
  • Check the pack size and pieces included. Genuine and third-party filters can differ.
  • Compare the total price with shipping, plus the seller's feedback and delivery estimate.

Care guidance

Replacement schedule

  • Filter O Carbon Replacement Filters (4-Pack) FLT51CB4: GermGuardian recommends replacing the activated carbon filter layer every 2 to 3 months depending on use. Package contains 4 carbon replacement filters.
  • Filter O FLT5100: The cited page describes FLT5100 as a True HEPA and treated-carbon replacement filter but does not state a replacement interval.

Usage and air quality can affect service life. Follow the cited manufacturer guidance for each part.

Free calendar reminder

Never forget a filter change

Enter the date you installed the filter and we'll make a repeating calendar reminder based on the official replacement schedule.

Filter O Carbon Replacement Filters (4-Pack) filter set FLT51CB4

The calendar reminder starts 3 months after this date and repeats on that schedule.

Your date is processed only in this browser. The .ics calendar file is generated locally on your device and is not uploaded to this site.

Frequently asked questions

What filter does the GermGuardian AP3250 use?

The GermGuardian AP3250 uses Filter O Carbon Replacement Filters (4-Pack) (FLT51CB4), Filter O (FLT5100) as its primary replacement filter parts. It also has these optional, specialty, or alternative compatible parts: Filter O PET PURE (FLT5100PT), Filter O SMOKE CLEAR (FLT5100SM), Filter O TOXIN CLEAR (FLT5100VO). Those parts are not simultaneously required primary filters.

How often should I replace the GermGuardian AP3250 filter?

GermGuardian recommends replacing the activated carbon filter layer every 2 to 3 months depending on use. Package contains 4 carbon replacement filters.

Where can I check replacement filters for the GermGuardian AP3250?

This page links directly to the cited official GermGuardian product page and shows sponsored individual eBay listings when a fresh exact-part snapshot is available, with an exact-part eBay search fallback. This site does not sell filters; match the part number and review the current source or seller listing before buying.

Official compatibility record

Manufacturer evidence

Each compatibility and care statement below is reproduced from the cited official manufacturer record. Check the source again before ordering.

Filter O Carbon Replacement Filters (4-Pack) FLT51CB4

Official Guardian Technologies product page identifies Filter O carbon replacement filter 4-pack, SKU FLT51CB4, as compatible with models AC3200, AC3250, AC5109W and AP3250.

Source checked
Replacement guidance
GermGuardian recommends replacing the activated carbon filter layer every 2 to 3 months depending on use. Package contains 4 carbon replacement filters.
Guidance checked

Filter O FLT5100

Official Guardian Technologies product page identifies Filter O, SKU FLT5100, as compatible with models AC3200, AC3250, AC5109 and AP3250.

Source checked
Replacement guidance
The cited page describes FLT5100 as a True HEPA and treated-carbon replacement filter but does not state a replacement interval.
Guidance checked

Filter O PET PURE FLT5100PT

Official Guardian Technologies product page identifies Filter O PET PURE, SKU FLT5100PT, as compatible with models AC3200, AC3250, AC5109W and AP3250.

Source checked
Replacement guidance
GermGuardian recommends replacing the Pet Pure HEPA filter set every 6 months. Carbon filters (FLT28CB4) can be replaced every 2 to 3 months.
Guidance checked

Filter O SMOKE CLEAR FLT5100SM

Official Guardian Technologies product page identifies Filter O SMOKE CLEAR, SKU FLT5100SM, as compatible with models AC3200, AC3250, AC5109W and AP3250.

Source checked
Replacement guidance
GermGuardian recommends replacing the Smoke Clear HEPA filter set every 6 months. Carbon filters (FLT28CB4) can be replaced every 2 to 3 months.
Guidance checked

Filter O TOXIN CLEAR FLT5100VO

Official Guardian Technologies product page identifies Filter O TOXIN CLEAR, SKU FLT5100VO, as compatible with models AC3200, AC3250, AC5109W and AP3250.

Source checked
Replacement guidance
GermGuardian recommends replacing the Toxin Clear HEPA filter set every 6 months. Carbon filters (FLT28CB4) can be replaced every 2 to 3 months.
Guidance checked

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