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TOTO THU738N-A Drain Valve for Dual Flush Toilet
The TOTO THU738N-A is a genuine OEM replacement drain valve designed for TOTO dual flush toilets. Replacing a worn or leaking drain valve restores proper flush performance and stops tank leaks at the source.
Key Details
- Genuine TOTO replacement part
- Designed for dual flush toilet models
- Part Number: THU738N-A
- Direct OEM fit - no modification required
Applications
Intended for use in TOTO dual flush toilet tanks. Verify your toilet model number before ordering to confirm compatibility. Consult the TOTO parts diagram or your toilet's installation manual for reference.
Manufacturer Resources
Product Specs
- Product Group:
- Washroom/Bath Accessories
- Product Subgroup:
- Parts and Accessories
- Product Type:
- Dual Flush Drain Valve
- Parts and Accessories Type:
- Drain Assembly
- Department:
- Plumbing
- Application:
- Sink
TOTO THU738N-A – Frequently Asked Questions
1) What does the TOTO THU738N-A part do in a dual flush toilet?
The THU738N-A is the drain valve, also called the flush valve, that sits in the tank of a TOTO dual flush toilet and releases water into the bowl when you flush. It is the genuine TOTO replacement part for that assembly, so a worn or leaking valve seal gets swapped out rather than the whole tank being replaced.
2) My TOTO tank keeps running and water trickles into the bowl. Is the drain valve the part to replace?
That symptom is what the THU738N-A addresses on a TOTO dual flush toilet. A drain valve that no longer seats lets tank water pass into the bowl continuously, and replacing the valve stops the leak at the source and restores the flush. If the water is instead overflowing into the overflow tube or the tank never stops filling, the fill valve is the suspect, not the drain valve.
3) Will the TOTO THU738N-A fit my toilet, or do I need to check the model first?
Check your toilet model number before you order. The THU738N-A is built for TOTO dual flush tanks specifically, and TOTO uses different drain valve part numbers across its model range. Your toilet's installation manual or the TOTO parts diagram for that model will name the correct valve. If the diagram calls for THU738N-A, this is it.
4) Do I have to modify anything to install the THU738N-A drain valve?
No modification. The THU738N-A is a direct OEM fit in the TOTO dual flush tanks it is specified for, so it drops into the same opening and uses the same connections as the valve coming out. That is the practical difference between the genuine part and a universal aftermarket flush valve, which often needs shimming or adapting to seat correctly.
5) Is TOTO THU738N-A an OEM part or an aftermarket equivalent?
Genuine TOTO, ordered by the manufacturer's own part number THU738N-A. For a property manager or MRO buyer standardizing repair parts across a building of TOTO fixtures, that matters: the OEM valve matches the tank it was engineered for, so the dual flush volumes behave as the toilet was rated rather than being changed by a substitute valve.
6) Does the THU738N-A come with a fill valve or a complete tank rebuild kit?
It is the drain valve alone. If your repair also involves the tank filling slowly, running on, or the flush buttons sticking, those are separate TOTO parts and need to be ordered by their own THU numbers from the parts diagram for your toilet model. Plan the job around a drain valve replacement, and add the fill valve or push-button assembly only if you have confirmed those are failing too.
How fast can I get the TOTO THU738N-A delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the
continental
U.S.
Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit,
reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the TOTO THU738N-A come with a warranty?
Absolutely. The TOTO THU738N-A is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the TOTO THU738N-A?
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product
selection,
installation tips, and troubleshooting. Contact Us
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