If your TOTO Washlet has started smelling like a regular toilet again, the fan probably isn't the problem. Most of the time, it's a saturated deodorizer cartridge that's stopped pulling odors out of the air before they escape the bowl.
The good news is that every TOTO Washlet deodorizer filter is a simple, tool-free part that snaps or slides into place, so once you know which cartridge your model uses, the fix takes a couple of minutes.
This TOTO Washlet deodorizer replacement guide walks you through finding your Washlet's deodorizer filter, matching it to the correct genuine TOTO cartridge, and replacing it step by step.
Locating Your Deodorizer Filter and Finding the Right Cartridge
Every TOTO Washlet air deodorizer works the same basic way, which answers a question we hear a lot: how does the TOTO Washlet air deodorizer actually work?
When you use the seat, a small internal fan draws air out of the toilet bowl and pushes it through a cartridge packed with activated carbon before releasing it back into the room. The carbon chemically traps odor molecules instead of covering them up with fragrance, which is why a healthy TOTO Washlet deodorizer doesn't smell like anything at all. Once that carbon media gets saturated, the fan keeps running, but air passes through without being cleaned, and odors start escaping the bowl again.
On nearly every current and recent Washlet, the deodorizer filter sits behind a small cover on the rear or underside of the main unit. To get to it, you'll typically need to release the seat from its base plate first (more on that in the next section), since TOTO tucks the cartridge inside the housing rather than leaving it exposed. Knowing your exact model number matters here because it determines both where the cover is and which cartridge you need.
Manual Button vs. Automatic Sensor Control
Not every Washlet controls its deodorizer the same way. Premium models like the S7, S7A, and NEOREST RS have a dedicated remote button that lets you manually force a high-speed "Power Deodorizer" boost or shut the fan off entirely.
Non-premium models like the S5, S2, S550e, S500e, C2, and C5 skip that button and handle everything through a seat sensor instead, switching the fan on the moment you sit down and pulling air through the cartridge the whole time you're seated.
When you stand up, that same sensor triggers a roughly 60-second high-power purge before the fan shuts off on its own, so there's nothing to press or remember.
TOTO Washlet Deodorizer Compatibility Chart
Match your exact Washlet model to the correct deodorizer cartridge below. Models are grouped by generation, since TOTO tends to reuse the same cartridge design across several models released around the same time.
Current Generation Models
| TOTO Washlet Model | Deodorizer Cartridge/Filter | Notes |
|---|---|---|
| WASHLET S7A & WASHLET S7 |
MPN: THU6587#01 SKU: TOTTHU6587-01 |
Genuine OEM slide-in cartridge, fragrance-free activated carbon. |
| WASHLET S5, WASHLET S2, WASHLET KS6 & NEOREST WASHLET G5A Integrated |
MPN: THU6904#01 SKU: TOTTHU6904-01 |
Shared cartridge across this generation. Currently backordered with the manufacturer until December 2026, so order ahead if you're planning routine maintenance. |
| WASHLET KS5 | MPN: THU6947#01 | TOTO's official parts manual for the KS5 lists a deodorizer louver assembly rather than a separate disposable cartridge. Contact us to confirm the correct part for your KS5. |
Older and Discontinued Models
| TOTO Washlet Model | Deodorizer Cartridge/Filter | Notes |
|---|---|---|
| WASHLET S300e, WASHLET S350e, WASHLET C100 & WASHLET C200 (all discontinued) |
MPN: THU9476 SKU: TOTTHU9476 |
Confirmed fit for S300e/S350e and C100/C200. See the compatibility note below before using this cartridge in a K300. |
| WASHLET S500e, WASHLET S550e, WASHLET C2, WASHLET C5 & WASHLET K300 (all discontinued) |
MPN: THU6474#01 SKU: TOTTHU6474-01 |
Covers this whole family of older S and C Series units. |
How to Replace a TOTO Washlet Deodorizer Filter
TOTO's Washlet deodorizer cartridges are designed for tool-free replacement, and a TOTO Washlet deodorizer filter replacement is nearly identical across the whole lineup. The main difference comes down to how much of the seat you need to move to reach the cartridge.
S7, S7A, S5, S2, KS6 & NEOREST G5A Integrated
These current-generation Washlets use a simple slide-in cartridge design, so most owners can swap the filter without fully detaching the seat.
- Flip the power switch on the side of the unit to off before doing anything else.
- Locate the deodorizer access point, typically a small door or slot near the rear or underside of the main unit. Check your owner's manual if you can't spot it right away, since the exact placement shifts slightly by model.
- Slide the saturated cartridge straight out. It shouldn't take much force. If it resists, double-check that you're pulling it in the direction the housing is designed to release it.
- Slide the new cartridge in until it clicks or seats fully into place.
- Close the access door or cover and switch the power back on.
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S500e, S550e, S300e, S350e, C100, C200, C2, C5 & K300
These older models generally require releasing the whole seat from its base plate to access the deodorizer compartment.
- Switch the power off at the side of the unit.
- Pull the Washlet slightly forward, then twist to release it from the base plate. Most models use a quick-release button you press first. Refer to your model's manual if the release mechanism doesn't budge easily; forcing it can damage the mounting.
- With the unit released, locate the deodorizer cover on the rear of the main body and remove it.
- Pull the old cartridge out. TOTO's own instructions note that you shouldn't yank it with excessive force, since that can damage the housing or the fan mechanism.
- While you're in there, it's worth wiping down or lightly brushing the reusable air intake filter nearby with a soft toothbrush. If you rinse it with water, let it dry completely before reinstalling.
- Insert the new deodorizer cartridge and press firmly until you hear it click into place.
- Replace the cover, remount the seat onto the base plate, and switch the power back on.
Regular Maintenance and Troubleshooting
How often to replace it: Most manufacturers, TOTO included, generally recommend swapping the deodorizer cartridge roughly every six months under normal household use. Bathrooms with heavier daily traffic, like a shared family bathroom or a commercial restroom, may need a fresh cartridge closer to every three to four months.
Signs your cartridge needs replacing: You can hear the deodorizing fan running, but odors are still escaping the bowl after use. The bathroom smells noticeably better right after cleaning but the smell creeps back within a day or two of normal use. It's simply been six months or longer since the last cartridge change and you can't remember swapping it.
💡 Pro Tip
Our TOTO Washlet Comparison Guide breaks down what each current model offers, so you can decide whether a new cartridge or a new seat makes more sense.
Signs the problem isn't the cartridge: If you don't hear the fan running at all, even right after use, that points to an electrical or fan issue rather than a saturated filter. Swapping the cartridge won't fix that.
Keep the intake filter clean too: Most Washlets have a separate, reusable air intake filter near the deodorizer cartridge that isn't meant to be replaced, just cleaned. A soft toothbrush works well for this. Doing it at the same time you swap the cartridge keeps airflow consistent through the whole system.
If you just installed a new cartridge and still smell something: Double-check that it clicked fully into place. A cartridge that's only partially seated won't force air through the carbon media the way it's designed to, so odors can bypass it entirely.
TOTO Deodorizer FAQ
Where can I buy genuine TOTO Washlet deodorizer cartridges?
Plumbing Deals is an authorized TOTO dealer and stocks genuine TOTO deodorizer cartridges and filters for current and many discontinued Washlet models. Buying from an authorized dealer matters here since off-brand cartridges aren't built to the same fit tolerances and can affect how well the fan and seal work together.
Can I use a different brand of deodorizer with my TOTO Washlet?
We'd recommend sticking with a genuine TOTO cartridge or a direct OEM-equivalent replacement built specifically for your model. TOTO's deodorizer bays are sized to a tight tolerance, and a cartridge that doesn't seal properly can let air bypass the carbon media, which defeats the purpose of replacing it in the first place.
If you’re unsure about what deodorizer cartridge replacement to purchase, then contact our expert team by live chat, email at contact@plumbingdeals.com, or phone at 888-682-5956!
What are the benefits of using a deodorizer cartridge in a bidet seat?
A working deodorizer cartridge keeps bathroom odors from escaping the bowl in the first place, instead of relying on air fresheners or ventilation to cover the smell afterward. It's a big part of what makes a TOTO Washlet feel like a genuine upgrade over a standard toilet, especially in bathrooms with limited airflow.
Why does my TOTO Washlet still smell even with the deodorizer running?
This almost always means the carbon cartridge is saturated and needs to be replaced. The fan can keep running fine even after the carbon media has stopped absorbing odors, so a running fan doesn't guarantee the deodorizer is actually working.
How do I turn off the deodorizer on my TOTO Washlet?
Most current TOTO Washlet remotes have a dedicated deodorizer button, sometimes shown as a fan or air-freshening icon, that lets you toggle it on or off. On models with a side control panel instead of a remote, look for the same icon among the buttons. If you can't locate it, your model's manual will show exactly which button controls it, since button layouts vary across the lineup.
Keep Your TOTO Washlet Smelling the Way It Should
A saturated deodorizer cartridge is one of the easiest TOTO Washlet issues to fix yourself, as long as you're working with the right part. Match your exact model number to the compatibility chart above, grab the correct genuine TOTO cartridge, and you'll have your bathroom back to smelling like nothing at all in a couple of minutes.
If you're ever unsure which cartridge your Washlet takes, or your model isn't listed here, reach out to our team. We're an authorized TOTO dealer and handle these compatibility questions regularly, whether that's by live chat, email at contact@plumbingdeals.com, or phone at 888-682-5956!
