You may also like
FLUSH VALVE ASSEMBLY
Manufacturer Resources
Product Specs
- Product Group:
- Washroom/Bath Accessories
- Product Subgroup:
- Parts and Accessories
- Product Type:
- flush valve
- Parts and Accessories Type:
- Flush Valve
- Department:
- Plumbing
- Application:
- Toilet
TOTO THU777-A – Frequently Asked Questions
1) What exactly is the TOTO THU777-A part?
THU777-A is a TOTO flush valve assembly, the drain valve that sits in the tank of a dual flush toilet and releases water to the bowl when flushed. It is a toilet repair part, not a complete tank trim kit or a fill valve.
2) Is the TOTO THU777-A the same thing as a fill valve or ballcock?
No. The THU777-A is the flush (drain) valve, the outlet assembly that dumps tank water into the bowl. If your problem is the tank refilling too slowly, overfilling, or running after the refill, that is the fill valve side and this part will not correct it. Replace this one when the tank leaks down into the bowl or the flush is weak because the valve is not sealing or not opening fully.
3) Will the THU777-A work on a single flush TOTO toilet?
It is specified as the drain valve for dual flush TOTO toilets, so it is the wrong part for a single flush tank. Single flush models use a different valve and actuator geometry. Match the replacement to the dual flush tank it came out of.
4) We maintain a building full of TOTO dual flush toilets. Can I stock one flush valve part number for all of them?
Not safely. THU777-A is a model specific TOTO flush valve assembly, and TOTO uses several different drain valve assemblies across its dual flush tanks. Pull the tank model number off each toilet and order the valve that is called out for it rather than standardizing on one number across a mixed fleet.
5) What should I order along with the TOTO THU777-A when rebuilding a toilet tank?
The THU777-A covers the flush valve side only. A full tank rebuild usually also needs the fill valve, the tank to bowl gasket and bolt set, and the supply connection if it is old. If you are only chasing a phantom flush or water trickling into the bowl, the flush valve alone is typically the part at fault.
6) Do I have to shut off water and drain the tank to change this TOTO flush valve?
Yes. Replacing a tank flush valve assembly like the THU777-A means closing the supply stop, flushing to empty the tank, sponging out the remaining water, and on most TOTO tanks lifting the tank off the bowl to reach the valve nut and gasket underneath. Plan on replacing the tank to bowl gasket while the tank is off.
How fast can I get the TOTO THU777-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 THU777-A come with a warranty?
Absolutely. The TOTO THU777-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 THU777-A?
You can call, text, or email our expert support team for fast answers. We’re here to help with
product
selection,
installation tips, and troubleshooting. Contact Us
Why buy the TOTO THU777-A from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support,
and
rewards on
every order.
Our team is always ready to help you choose the right product for your project.