Fujitsu – time to clean the air filters!

It’s definitely time to clean this air filter

After receiving a question recently about cleaning the Fujitsu’s air filters, I thought I’d better check mine. Good thing – yuck!

Fortunately, a quick spray down  in the sink and they’re good as new. Just remember to spray from the back side to blow the gunk out of the filter. Also, let the filters dry out before using them.

In addition to the two large mesh filters, there are a small foam and pleated filter below them. Clean and dry those and you’re good to go.


33 thoughts on “Fujitsu – time to clean the air filters!

  1. Hi Ted,
    Does it make a difference which side you put the Polyphenol Catecin and the Negative ion filters on? Which goes on left and which goes on right? Or no difference.

  2. I have not replaced the little filters either. The dealer said not to bother, they dont do much. However, I have had to have them come back twice now in three years because the little black loovers get big dust bunnies on that look like mold! They come and use a little spray gun with a huge plastic cover over the wall mount that drains into a funnel into a bucket. I have been trying to find replacement filters now also. I was wondering about purchasing an an air purifier to see if that would help.

    • No matter how clean you keep your home, the air filters are going to do what they do – get dirty 🙂
      It’s unfortunate that they’re special filters, but just consider replacement part of the basic maintenance of the unit. I have to admit that I often forget about the filters and end up finding them very dirty and in need of replacement.
      You can pull them and wash them even though they say you can’t. Just let them dry well before putting them back into the unit. While it’s true that they lose their “magical properties” after a while, they’ll still serve to filter the dust in the air for years if you keep them cleaned off every few months.
      However, I would recommend continuing with periodic maintenance because it’s quite common for the condensate pans to get scummy and clog the lines. If that’s allowed to go, you’ll end up with a water leak in your wall which can cause serious damage. I’ve seen a lot of people complaining because they think the units are poorly made due to this type of clogging. However, it’s just a fact of nature – part of the operation of an air conditioner is pulling water out of the air and that standing water that drains out of the unit will get scummy over time.

      • Hello

        Could you say what you mean by this comment:

        “it’s quite common for the condensate pans to get scummy and clog the lines.”

        Thank you


      • The condensate pans in air conditioning systems often contain water that hasn’t fully drained off. This in turn provides a nice habitat for various algae bacteria Etc. Over time this can also build up in the condensate lines that should be draining the pans but they get clogged and need to be blown or sucked out.

  3. Thanks for this information. Regarding the air cleaning filters. Ours were never installed and I cannot understand the manual. I would appreciate any help you can give me on figuring this out. Where do you put the Apple catechin filter UTR-FA16 and the ion deodorizing filter UTR-FA16-2 Do you use both of them in the unit. . One on one filter, and one on the other? Are these necessary or optional? What happens if you don’t use them.
    thank you for any information you can give me.

    • Install one on each. In my users guide on page nine it states that filter UTR-FA16 can not be washed and should be replaced every 3 months. The blue filter-UTR-FA16-2 can be washed every 3 months and replaced every three years. Fujitsu also recommends clean the large air filters be cleaned every two weeks. If you decide to use water first remove the two small filters and spray water from behind so that it will force the accumulated dust off the air filter. The manual is very hard to read as they used a very cheap translation programme or the person who did the translations abilities were less than they thought they were. You should be able to download the Operation Manual from Fujitsu. Good luck.

  4. Hello, for the person in Nova Scotia looking for the replacement filters (small white pleated and the blue one) we get ours through Twenty Degrees, they have an office in the Burnside Industrial park. We a 9 and a 12 in our house and it roughly $80 total to replace the filters in both units.

    My tip of the day for cleaning the large mesh filters, we get paid every 2 weeks, I clean them on the same schedule. If you have animals you may want to do it every 2 weeks or more frequently depending on how furry your pets are.

  5. Hi Ted,

    You said that in addition to the large filters you can clean the smaller ones behind it too. How? With just water of also some soap added to it? Do I vacuum them in advance? Thanks sofar, GERT

    • I’ve just rinsed them in the sink like a sponge. I didn’t even use soap and they seemed pretty clean. My philosophy is to clean it gently to avoid any damage though they seem pretty durable.

  6. In an effort to find replacement filters, I came upon this thread of comments on the Fujtsu inverters.
    I just cleaned the two air filters, but I cannot figure out how to turn the flashing economy light off. The unit turns on and off but the heat will not run.

    Can anyone shed some light on this?

    Many thanks,

  7. Just like you guys I have a Fujitsu 12 RLS two I installed November 2012. It’s saved me a ton of money in wood pellets and propane.
    We’re all smart enough to know that these filters need to be cleaned at least monthly during heating season. So here it is early February, and I finally looked up my filters. Yep, Ted, I used the term yuck also, only I used it twice double yuck. I too gave up on the Apple Catechin filter and ionizing filter. There are cheaper ways to ionize air.

    Calling for 0 again tonight. (Hershey,Pa). neighbor lady down the hill has a 15 RLS two, installed last September. Better stop down to check hers. Bet it looks like your picture.
    Loving my 12 RLS2.

    • It’s too darned easy to forget! I wish they had a timer and warning like my thermostat for the central system. At least then I’d be checking it a bit more. Now, I’m making a list of calendar items to remind me regularly.

      Actually, this should be a “tip of the day” – set up recurring calendar reminders for all those household items that we tend to forget about – checking the water filter (for those of us with wells), check the air filters, check the generator oil level, etc.

    • Hello John, thanks for those comments. Do I understand that you removed the Apple Catechin filters and didn’t replace them? I think Fujitsu says replace every 3 years but they are very expensive.
      Jack Leonard

  8. Hello Ted, Like you I’ve never replaced the small filters on my Fujitsu 12RLS and I wonder if they are still working and how much they restrict airflow? I certainly see a big difference whenever I clean the big filters even though they don’t appear all that dirty. There seems to be much stronger and warmer airflow. I wonder how often they should be cleaned? I usually wash them in the sink.

    • Hey Jack, I just check the filters monthly and clean them in the sink when they look a bit dirty. Same thing now with the smaller filters.
      For me, a little dusty coating isn’t a big deal, and it’s pretty clear when they’re at the point that they should be cleaned. Realistically, I forget for a month, come back, and notice “man, these are really dirty, I gotta clean them ASAP” 🙂

  9. Does anybody know where we can purchase the air cleaning filter (UTR-FA16) and the deodorizing filter (UTR-FA16-2). We are in Nova Scotia and can’t find them anywhere – can’t even find them on the web.

  10. Thanks for the tip. I need more help. you say “In addition to the two large mesh filters, there are a small foam and pleated filter below them. Clean and dry those and you’re good to go.” I have an R15RLS-2 now well overdue for filter cleaning but I find my Operating Manual very confusing once I get past the reference to the large washable screen filters. Then I’m told that the Polyphenol Catechin filter UTR-FA 16 should be replaced every three months — “they cannot be washed and reused.” I have searched fruitlessly on the web for replacement filters and come up empty. Can you help clarify the situation?

    With thanks, BEWILDERED

    • Good point! For those wondering what you’re referring to, check this link. And here’s a reference to buying these expensive little filters.

      Here’s what Fujitsu says about the filters:
      “These systems feature both an Apple-Catechin Filter and an Ion Deodorizing Filter. The Apple-Catechin Filter absorbs dust, mold spores and microorganisms by static electricity. Growth is inhibited and deactivated by the polyphenol ingredient extracted from apples. The Ion Deodorizing Filter deodorizes by powerfully decomposing absorbed odors using the oxidizing and reducing effects of ions generated by the ultra-fine particle ceramic.”

      Personally, I’ve never purchased a replacement for this filter, so it’s probably ineffective at this point. At $57, I doubt I will be either!

      Thanks for pointing this out – this particular filter can’t be cleaned.

  11. On my Fujitsu, you can set it so the green light will blink after a certain amount of use, reminding you to change the filter. if you don’t have the install manual, you can probably find it on line. The setup is a little cryptic (designed more for the HVAC folks than the owners) but you can get it set up to remind you. Yeah, your filter looks pretty bad. 🙂

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