How to Replace a Toilet Fill Valve – Part 2

Maintenance, Plumbing, Toilets | April 17, 2010 by Bob Jackson | 2 Comments

This project is continued from Part 1.

Unscrew the coupling nut that attaches the water supply hose to the toilet fill valve. This is located under the tank on the left side of the toilet. The nut usually has large “wings” to unscrew by hand. If the nut is stuck, use a large adjustable wrench on the hex head of the nut.

Take care to shut off the water supply valve (valve at the bottom of the photo) before unscrewing the nut or you’ll have water gushing out and flood the bathroom!

Remove the Water Supply Hose Coupling Nut

Water supply hose couple nut unscrewed from the fill valve threads. The supply hose is now loose – several ounces of water will run out of the fill valve, place a towel on the floor to catch the water. It will seem like a lot of water is running out but it’s brief.

Water Supply Hose Coupling Nut

The lock nut holds the fill valve securely against the toilet tank. Use a 10-inch adjustable wrench (or channel locks will do in a pinch) to unscrew the nut.

Unscrew the Lock Nut with an Adjustable Wrench

The fill valve sits loosely inside the tank when the lock nut is removed.

Toilet Fill Valve Lock Nut

If you are not replacing the water supply hose, then skip the next two steps. Since I’m replacing the PVC plastic fill host with a Brasscraft reinforced hose, the old PVC supply hose is removed and discarded. Unscrew the compression nut with the adjustable wrench. If the nut is unusually tight, place a second wrench on the valve body to avoid torquing the copper water pipe.

Unscrew the Water Supply Host Compression Nut

Here’s the old PVC supply hose (a.k.a. toilet connector). I’ve not had a PVC supply hose fail on me and cause flooding, but this $2 plastic hose is simple to replace with a $6 reinforced Brasscraft hose.

Old PVC Water Supply Hose

After unscrewing the lock nut, the old ballcock fill valve simply lifts out of the tank.

Lift the Ballcock Fill Valve out of the Toilet Tank

The toilet tank is ready for the new fill valve and flapper. Now’s a good time to wipe down the inside of tank to remove any remaining sediment and iron stains that couldn’t be reached before.