2-1/2" Toilet Outlet (Flush) Valve with Flapper: Repair Guide
By Maintenance Depot Plumbing Team · Last reviewed
Quick answer
The 2-1/2" toilet outlet valve with flapper replaces the whole flush valve when the old one is cracked or its seat is worn. Measure the tank opening first to confirm you need 2-1/2".
If you've replaced the flapper and your toilet still runs, the problem may be the flush valve itself. The 2-1/2" toilet outlet valve with flapper replaces the whole assembly.
Specs at a glance
| Spec | Detail |
|---|---|
| Product | Toilet outlet (flush) valve with flapper |
| Size | 2-1/2" |
| Includes | Flush valve and flapper |
| Requires | Removing the tank to install |
What does the flush valve do?
It's the opening at the bottom of the tank that releases water into the bowl. The flapper seals it. A cracked valve or a worn seat lets water leak constantly.
2" or 2-1/2"?
Measure the drain opening at the bottom of the tank:
- About 2" across means a 2" flush valve
- About 2-1/2" to 3" means a 2-1/2" flush valve
This kit is for 2-1/2" openings.
Replacement overview
- Turn off the water, flush and sponge out the tank.
- Disconnect the supply line.
- Remove the tank from the bowl by unscrewing the tank bolts.
- Unscrew the large nut under the tank and remove the old flush valve.
- Install the new valve with its gasket, tightening the nut firmly but carefully.
- Fit a new tank-to-bowl gasket and remount the tank.
- Adjust the overflow tube height, fit the flapper and chain, reconnect the water and test.
Tip
While the tank is off, consider replacing the fill valve and flush handle too. Maintenance Depot stocks both.
Frequently asked questions
How do I know if I need a 2" or 2-1/2" valve?
Measure the drain opening in the bottom of the tank: about 2" means 2"; about 2-1/2" to 3" means 2-1/2".
Do I need a new tank-to-bowl gasket?
Yes, replace it whenever the tank is removed.
Why replace the flush valve instead of the flapper?
If the valve is cracked or the seat is worn, a new flapper will not stop the leak.
Buy Toilet Outlet Valve with Flapper 2-1/2" at Maintenance Depot