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Replacement filter set

GermGuardian Filter O FLT5100 replacement filter

Filter O (part FLT5100) fits GermGuardian AC3200, GermGuardian AC3250, GermGuardian AC5109 and GermGuardian AP3250, according to the official GermGuardian product page.

Official GermGuardian fit · checked

GermGuardian models that use Filter O FLT5100

This filter is listed for 4 models. Open a model to see its complete list of primary, optional, and specialty filters.

Before you order

What to check in a FLT5100 listing

  • The listing names part FLT5100. Similar-looking filters are not proof of fit.
  • Your purifier is one of the compatible models: GermGuardian AC3200, GermGuardian AC3250, GermGuardian AC5109 and GermGuardian AP3250.
  • The pack size and pieces included match what you need. Genuine and third-party filters can differ.
  • The total price with shipping, seller feedback, and delivery estimate work for you.

Care guidance

Replacement schedule

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

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

Compare compatible options

These share at least one compatible model but may do a different job, such as a carbon pre-filter or a specialty version. Check each part page before buying.

Frequently asked questions

How often should I replace the GermGuardian Filter O (FLT5100)?

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

Which GermGuardian models use the Filter O FLT5100?

According to the official GermGuardian product page, Filter O (FLT5100) fits GermGuardian AC3200, GermGuardian AC3250, GermGuardian AC5109 and GermGuardian AP3250. Verify the model label on your unit before ordering.

Do aftermarket FLT5100 filters work?

Marketplace listings may be from the manufacturer or a third party. Match the exact part number FLT5100, review the listing details, and verify the model label on your unit before buying.

Official compatibility record

Manufacturer source

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

Guardian Technologies GermGuardian FLT5100 - Filter O

Source compatibility checked 2026-08-29. Recheck the listing and your purifier label before ordering.