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How to Replace a Toilet Fill Valve

Bob Jackson
Last Updated on
by Bob Jackson

This project explains how to replace an old style toilet ballcock valve with a new Fluidmaster Whisper Fill Valve. The toilet flapper valve and toilet connector water hose are also replaced for reliability and to prevent leaks. The repair required about 20 minutes and cost less than $20 in parts.

Loud Noise from Toilet after Flushing

The toilet ballcock valve started making a loud humming noise as the tank was nearly full and the fill valve closed. The hum could be heard throughout the house like a ghostly moan. The toilet tank acted like a bell to amplify the noise. The ballcock valve was probably 10 years old and getting worn out. This is the original toilet ballcock valve and float ball:

Replace a Toilet Fill Valve: Old Ballcock Valve
Replace a Toilet Fill Valve: Old Ballcock Valve

Common Toilet Fill Valve Problems

The toilet fill valve may need replacing if any of the following problems occur:

  • The tank doesn’t refill after you flush.
    The valve may be stuck. Take the lid off the tank and jiggle the float to open the valve. Minerals and sediment tend to build up over time inside the valve causing it to stick.
  • The toilet runs continuously after you flush.

    • Check that the flapper valve is closing properly and/or the flapper chain isn’t getting kinked and preventing the flapper from closing. You don’t want a lot of extra links in the chain or it will tend to kink up – effectively shortening the chain. If you suspect the flapper isn’t making a water tight seal, put a few drops of dark food coloring in the tank and see if colored water appears in the bowl. If so, the flapper is leaking and needs to be replaced.
    • If the water level is so high in the tank that the water spilling into the overflow pipe, the fill valve is bad. A running toilet can waste hundreds to thousands ($$$) of gallons of water in a day. Shut off the water supply valve (see below) and replace the fill valve.
  • The fill valve hums or makes a moaning sound like mine was doing.
  • If the toilet won’t flush and the flush handle feels light (swings freely), the flapper chain or tank arm may be broken. Look inside the tank and inspect the flush handle, lift arm and flapper chain for problems. Replacement parts are readily available for these items at any home improvement store and the repair is simple.
  • If you have a ballcock valve with a float ball, check if the float ball is cracked and water logged. There shouldn’t be any water inside the float ball. You may only need to replace a cracked or broken float ball.

How to Replace a Toilet Fill Valve

I purchased a Fluidmaster Whisper Fill Valve and braided supply hoses. I bought several hoses because I wasn’t sure if I needed the 3/8″ or 1/2″ compression nut or if the 9″ or 12″ hose length fit best. As it were, the water supply valves in my home are the 3/8″ size.

Fluidmaster Whisper Fill Valve and BrassCraft Toilet Connector Hoses
Fluidmaster Whisper Fill Valve and BrassCraft Toilet Connector Hoses

I prefer the high quality Brasscraft Speedi Plumb PLUS braided hoses because they’re more flexible and reliable than the PVC plastic supply hoses. The few dollars extra for the braided hose is worth the peace of mind over a burst PVC plastic hose and ensuing flood damage.

The Fluidmaster kit includes a nice set of instructions, the refill valve and flapper.

Toilet Repair: Fluidmaster Whisper Fill Valve Kit
Toilet Repair: Fluidmaster Whisper Fill Valve Kit

Jumping ahead in the repair, compare the Fluidmaster and Brasscraft parts (above) to the old ballcock valve and PVC supply hose that was removed from the toilet:

Old Toilet Ballcock Toilet Valve and PVC Supply Hose
Old Toilet Ballcock Toilet Valve and PVC Supply Hose

Trivia: The ballcock valve was invented by Thomas Crapper.

Remove the Old Ballcock Valve and PVC Water Supply Hose

Disassembly and removal of the ballcock valve and PVC supply hose is simple and requires only an adjustable wrench.

Step 1: Locate the water supply valve. It is normally on the left of the toilet.

Toilet Repair: Water Supply Valve and PVC Hose
Toilet Repair: Water Supply Valve and PVC Hose

Step 2: Turn off the Water Valve

Turn the water supply valve clockwise to turn it off. This contractor grade (i.e. cheap) valve with a plastic shaft leaks a bit when turned. Do not over tighten the valve to avoid breaking it. I plan to replace this valve with a quality 1/4 turn angle ball stop valve.

Turn the Toilet Water Supply Valve Off
Turn the Water Supply Valve Off

Step 3: Flush the Toilet and Hold the Handle to Drain the Tank

Hold the handle to allow most of the water to drain out of the tank. There will still be about 1/2 inch of water in the bottom of the tank.

Toilet Fill Valve Repair: Hold the Toilet Flush Handle to Drain the Tank
Toilet Fill Valve Repair: Hold the Toilet Flush Handle to Drain the Tank

The water in the toilet tank is clean – the same water that comes out of the kitchen faucet – and brownish stains on the sides of the tank is mostly iron and sediments, a result of the water sitting in the tank for long periods of time.

Step 4: Unscrew and Remove the Float Ball

The float ball simply screws on the end of the lift arm.

Replace a Toilet Fill Valve: Unscrew and Remove the Float Ball
Replace a Toilet Fill Valve: Unscrew and Remove the Float Ball

Step 5: Sponge the Remaining Water from the Tank

Use a sponge to remove the rest of the water from the tank. Also wipe down the sides and bottom of the tank to remove the sediment.

Tip: You could wring out the sponge in a bucket. Why bother? Just hold open the flapper valve and wring out the sponge – the water will run into the bowl. Way less drippy and less motion!

Toilet Fill Valve Repair: Sponge Water out of the Toilet Tank
Toilet Fill Valve Repair: Sponge Water out of the Toilet Tank

Step 6: Remove the Refill Tube

Pull the refill tube off the fill valve and out of the overflow pipe holder:

Replace a Toilet Fill Valve: Remove the Refill Tube
Replace a Toilet Fill Valve: Remove the Refill Tube

Step 7: Unhook the Flapper Chain from the Tank Lever

You can skip this step if you’re not replacing the toilet flapper, but might as well replace the flapper because it’s easy and flappers do wear out and leak.

Toilet Repair: Disconnect the Flapper Chain from the Tank Lever
Toilet Repair: Disconnect the Flapper Chain from the Tank Lever

Step 8: Unhook the Flapper from the Fill Tube Mounting Ears

Slip the flapper off the over flow tube mounting ears to remove:

Toilet Repair: Unhook and Remove the Flapper
Toilet Repair: Unhook and Remove the Flapper

Step 9: Take the Flapper out of the Tank

Toilet Repair: Remove the Flapper and Chain
Toilet Repair: Remove the Flapper and Chain

Progress thus far – the toilet ballcock valve and refill tube holder will be removed next.

Replace a Toilet Ballcock Valve
Replace a Toilet Ballcock Valve

This project is continued in How to Replace a Toilet Fill Valve – Part 2.

Take care,

Bob Jackson

3/8" compression nut7/8" wing nut toilet connectorfix a toilet flush valveflapper valvefloat ball
Bob Jackson
Bob Jackson
Technology product manager by day and a prolific handyman in the evenings and over the weekends. Bob was the founder of the original Handyman How To website and that tradition continues on this site with excellent new handyman content into the future.
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