How to Replace a Toilet Fill Valve – Part 5

How to Replace a Toilet Fill Valve: Reinstall the flapper valve and adjust the water level in the toilet tank.

This project is continued from How to Replace a Toilet Fill Valve – Part 4.

The Fluidmaster Fill Valve kit includes a new flapper (top item in the next photo). The Fluidmaster flapper valve includes an overflow tube mounting ring held by the spring steel U-shaped clip which doesn’t fit my toilet. This isn’t a problem because the overflow tube mount ring unsnaps from the flapper bracket arms. Because I’d recently replaced the Korky Toilet Flapper (bottom of photo) and it’s in very good condition, I choose to reinstall the Korky flapper valve and keep the Fluidmaster flapper as a spare. This way I won’t have to adjust the flapper valve chain length where it connects to the flush lever arm.

Toilet Repair: Korky (bottom) and Fluidmaster (top) Toilet Flappers

Toilet Repair: Korky (bottom) and Fluidmaster (top) Toilet Flappers

Install the flapper – either the old or new item – and reconnect the lift chain to the tank level. For details see How to Fix a Broken Toilet Flapper Valve and Lift Chain.

Toilet Fill Replacement: Pre-Flush Checks

Verify the flapper valve falls completely closed when the flush handle is released and the lift chain is slightly slack. Any tension in the lift chain can prevent the flapper valve from closing complete and cause a leak with high water bills.

Install a Toilet Fill Valve: Flapper Valve Closed and Lift Chain Slightly Slack

Install a Toilet Fill Valve: Flapper Valve Closed and Lift Chain Slightly Slack

Press the flush handle a few times and see that everything works smoothly with the flapper raising and falling freely:

Toilet Repair: Flush Handle Pressed and Flapper Valve Open

Toilet Repair: Flush Handle Pressed and Flapper Valve Open

Adjust the Toilet Fill Valve Critical Level

The toilet water supply valve must still be shutoff before proceeding.

Verify the critical level mark on the toilet fill valve is a minimum of 1 inch above the top of the overflow tube to comply with Building Code requirements. If the critical level is too low, the valve height needs to be adjusted. The “official” way to adjust the height is uninstall the fill valve and turn the shank to lengthen the fill valve. “What?! But I just installed the darn thing! I’d have unscrew all the connections and remove the valve!” There is a simple shortcut:

  1. Verify the water supply valve is shut off.
  2. Lift the lock ring up the shank body.
  3. Grasp the gray valve body above the threaded shank – do not pull on the float cup or black valve cap.
  4. Pull the valve body to lengthen the valve height – you’ll hear/feel a couple of clicks.
  5. Slide the lock ring back down into place. Double check the lock ring is securely in its original place.

Remember – the lock ring is the only thing holding the valve body onto the shank and prevents the valve from popping off when the water supply is On.

Fill Valve Critical Level – 1 inch Above Overflow Pipe

Toilet Flush Test and Leak Check

Turn on the water supply and check for leaks as the tank fills with water. Gently tighten any connections if you find a leak. The new toilet fill valve and water level in the toilet tank should look like this:

Toilet Repair: Fill Valve, Flapper and Flush Arm Mechanism

Toilet Repair: Fill Valve, Flapper and Flush Arm Mechanism

Flush the toilet to verify the cycle works correctly. Water exits the fill valve near the bottom of the toilet tank and the refill tube fills the bowl.

Toilet Repair: Fill Valve Refilling the Tank and Bowl

Toilet Repair: Fill Valve Refilling the Tank and Bowl

Adjust the Toilet Fill Valve Water Level

The water level line should be marked by the toilet manufacturer on the back of the tank. If not, the water level should be about 1 inch below the top of the overflow pipe.

Toilet Repair: Water Level Marked on Back of Toilet Tank

Toilet Repair: Water Level Marked on Back of Toilet Tank

To raise or lower the water level in the toilet tank, turn the adjustment screw on the toilet fill valve. The screw and rod controls the distance between the valve arm and the float cup. Flush the toilet to verify the final water level.

Install a Toilet Fill Valve: Water Level Adjustment Screw and Rod

Install a Toilet Fill Valve: Water Level Adjustment Screw and Rod

An alternate perspective of the finished job:

Install a New Toilet Fill Valve

Install a New Toilet Fill Valve

Check the connections again and after one hour to be certain there are no leaks. Tighten any leaking connections as needed. Toilet paper is an excellent leak detector because the slightest amount of water will show on the paper.

Take care,

Bob Jackson

Copyright © 2014 HandymanHowTo.com   Reproduction strictly prohibited.

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7 Responses to How to Replace a Toilet Fill Valve – Part 5

  1. Donna Hill May 11, 2011 at 6:37 pm #

    I found your instructions very helpful, but I have a leak at the connection of the water hose and the bottom of the toilet. I hand tightened the lock nut. And the instructions in the box said to “use the existing cone washer” because I have metal spiral tubing. Then I put on the new coupling nut and attached it. Nothing tells me how tight to tighten the coupling nut. I think everything works, but I have a leak under the coupling nut. What do I do about this leaking problem?

    Thanks,

    Donna

    • Bob Jackson May 11, 2011 at 7:01 pm #

      > the instructions in the box said to “use the existing cone washer” because I have metal spiral tubing.
      You should always use new washers when replacing a fill valve or toilet connector hose because the old washers may be crushed or aged. I recommend replacing the connector hose with a new one that includes the cone washer such as the Brasscraft hose as illustrated in Part 3 and Part 4 of the project. Part 3 has a closeup of the cone washer. These are available for Lowes, Home Depot, etc. for several dollars.

      Did you replace the fill valve and install a new shank washer? It could be leaking where the shank washer seals against the inside of the toilet tank. Be sure to clean any sediment deposits on the inside of the tank around the fill valve hose opening.

    • Bob Jackson May 11, 2011 at 7:13 pm #

      > Then I put on the new coupling nut and attached it. Nothing tells me how tight to tighten the coupling nut.
      Sorry, I missed this question in my first reply. Tighten the coupling nut (wing nut) until it’s makes makes contact and seats against the cone washer, then tighten another 3/4 turn. It should be firm and snug, but you don’t want to crank down the nut and crush the cone washer. Overall it’s pretty forgiving, so do what feels right, check for a leak after 10 to 15 mins, then give it another 1/2 turn if there’s a drip.

  2. Rick September 11, 2012 at 9:34 pm #

    Thank you for the great instructions.Helped me allot.
    Next question though. My toilet is very noisy filling with water.
    Is there away of fixing this and how please.

    • Bob Jackson September 13, 2012 at 5:28 am #

      If you installed a “Whisper” or “Quiet” toilet fill valve and filling the tank is still noisy, try partially closing the water supply shutoff valve to reduce the water pressure. Experiment to find a balance between the noise level and tank refill rate.

  3. Lisa August 10, 2013 at 10:16 am #

    Hello. your website is so helpful and clear pics, thanks!
    I have a question Re: Critical Level Mark (under the third picture on this page)

    …Do you think water will keep filling up the tank
    *IF* the critical level (I call it the grey ring) is LOWER than the very top of overflow pipe?
    We got a new valve (Fluidmaster uk400) replaced a while ago by a plumber. water fills in the tank as usual, but after 3-5 hours it reaches to the overflow pipe. we’ll get him soon to adjust it but i just wanted to know before he comes..

    I haven’t checked the debris underneath the sealing washer though.

    Thanks in advance,
    Lisa

    • BobJackson August 10, 2013 at 6:36 pm #

      I’m glad you like my website.

      > Do you think water will keep filling up the tank
      > *IF* the critical level (I call it the grey ring) is LOWER
      > than the very top of overflow pipe?
      The vertical travel (or movement) of the float cup is limited to about 1/2 inch below the critical level mark. As the toilet tank fills with water after a flush, the float cup moves upward with the rising water level until the float arm will closes the water valve to stop filling the tank. The purpose of the critical level mark is to ensure the fill valve always remains above the water line; should the water level rise too high, it will spill into the overflow tube before the fill valve is submerged. (Also, the overflow tube must be below the level of the toilet handle or water could leak around the handle.) The reason for keeping the fill valve always above the water level in the tank is to avoid the possibility of water being siphoned from the toilet tank into the water supply line. Building/plumbing codes require modern toilet fill valves to be equipped with an anti-siphon mechanism (e.g. check valve) to prevent water siphoning. Water siphoning from the toilet tank through the fill valve into the water supply line could otherwise happen if water pressure is lost due because the city is working on the water lines or the water valve was shutoff at the meter to do plumbing work in the home.

      > We got a new valve (Fluidmaster uk400) replaced a while ago by a plumber.
      > Water fills in the tank as usual, but after 3-5 hours it reaches to the overflow pipe.
      It’s clear from your description the flush valve is improperly installed. The fill valve is not fully closing which allows water to fill the tank until it reaches the overflow tube and spills into the bowl. Given the incorrect adjustment of the critical level, the float cup is probably fully submerged at it’s maximum upward travel limit pressing hard against float cup arm which actuates the fill valve. I haven’t experimented with the Fluidmaster fill valve to see if this will cause the valve to leak, but it needs correcting first.

      > I haven’t checked the debris underneath the sealing washer though.
      Assuming the Fluidmaster toilet fill valve is installed and adjusted correctly, see the TOILET SYMPTOM: Valve Runs Non Stop troubleshooting steps at the Fluidmaster Fix It Zone to clear debris or replace the seal. Pay special attention to “holding a cup upside down” over the fill valve so water doesn’t squirt all over the bathroom.

      If the fill valve seal is bad or blocked by debris I’d replace the entire unit because fill valves aren’t expensive. I replace mine every 5 to 7 years on average, water quality is big factor for fill valve longevity… minerals and such.

      Last recommendation is to hire a different plumber because he made a bonehead mistake on the critical level adjustment.

      Hope this solves your leak.

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