If you have a fill valve on your toilet that is not shutting off and is wasting water or, not refilling the tank properly, or making noises in many cases the Fluidmaster 400A is the ideal replacement choice. The 400A fits into more applications, is less expensive, and works better than many other fill valves, making it the ideal replacement choice in many toilet makes and models.
The first thing you need to do is lift off the tank lid and look inside the tank at the fill valve that is there. You need to look at it and make sure that the Fluidmaster 400A will fit in your toilet. The height is adjustable from 9” to 14” and it has a small diameter that usually does not conflict with other parts in the tank. There are some toilets that have proprietary fill valves that mount in the corner of the tank, incorporate parts of the flush valve with the fill valve, and some like the Toto G-Max have a special fill valve that has a higher bowl refill rate. Take a look at the two pictures below showing different fill valves to see how they compare with yours and see if the Fluidmaster 400A is compatible with your toilet. If you have a fill valve that is very complicated that usually goes along with expensive and I would seek the advice of a plumber. Some of the valves pictured below in the second picture down are in the $400 price range. A knowledgeable plumber may be able to rebuild them if parts are available.
Common Fill Valves
Most fill valves are quite common resembling the ones in the picture to the right which can be clicked on to enlarge. These fill valves or, ballcocks as we call them in the trade are stand alone devices and not tied to other components in the tank. The tank mounting hole is far enough out of the corner of the tank where the Fluidmaster 400A can be installed without interference from the tank or, other components. In some cases The Fluidmaster 400A will work with low profile toilets but in other cases the valve height cannot be adjusted low enough or the operational range is insufficient in which case a proprietary fill valve would be required.
Proprietary Fill Valves
On a few toilets there are designs which require the use of a special fill valve. Sometimes it is a low profile tank where the Fluidmaster 400A cannot be adjusted low enough or, be set to turn on and off in the right range. Other times the manufacturer just puts the hole in the tank to close to a corner or side so the float will hit against the tank not having the clearance it needs to operate. Sometimes they also have unusual tubes that flow water to the bowl at different times triggered by the water level in the tank or, different bowl water level replenishment rates. Many of the possible fill valves that would not be able to be replaced by a Fluidmaster 400A fill valve are pictured to the left in the picture which you can click on to enlarge.
How To Change A Fill Valve Step By Step
The following steps should be followed to replace the fill valve:
1.) Shut of the angle stop valve supplying the toilet. This is usually located under the tank on the left side where the supply comes out of the wall or, floor. Flush the toilet and hold the lever so the tank empties as much as possible. Open the tank lid and place it on the floor out of the way. Placing it on the floor ensures it does not fall and break. Tank lids can be quite expensive. Remove the rest of the water from the tank using a sponge, wet vac, or, just be ready to catch the rest of the water with a bucket when the fill valve nut is loosened. Verify that the water is off completely.
2.) Place a small tray to catch water under the angle stop valve if it comes out of the wall or, if it comes through the floor place rags around the pipe. Using a small adjustable wrench unscrew the nut on the supply line securing it to the angle stop valve. Then using channel lock pliers remove the nut securing the supply line to the old fill valve shank. A small amount of water will come out during this process.
3.) You are now ready to remove the nut on the old fill valve shank. This is what secures the old fill valve in place. Use channel locks to loosen it. If you have removed all the water nothing will leak but if you haven’t you will need to get a bucket in place to catch the water that is remaining in the tank. Once the nut is removed the old fill valve will lift out of the tank. Unclip the bowl refill tube from the overflow tube and discard the whole assembly.
4.) Remove the new fill valve and parts from the box. Cut the cone washer from inside of the shank washer. Place the shank washer on the fill valve shank with the smooth side facing up, the bottom of the shank washer has a ridge near the threads that helps the valve line up properly to the hole through the tank.
5.) Place the new fill valve in the tank to check its height. Look at the picture to the right which you may click on to enlarge and note the critical level mark on the ring of the valve. This ring must be at least 1” above the overflow tube for the valve to work properly. The proper operation of the anti siphon valve depends on this height to protect your drinking water from the toilet tank back-flowing into it. The valve body has 2 pieces that adjust the height by screwing the bottom shank while holding the top of the valve body still. Once the height is correct place the refill tube on the fill valve then place the valve in the tank in a manner that does not conflict with the other parts in the tank and the refill tube points towards the overflow tube. Secure the fill valve in place with the nut provided. Do not over tighten as the tank and or, plastic shank of the fill valve can crack and leak. Make sure that the float does not hit the walls of the tank or the trip lever.
6.) I recommend using a braided stainless steel supply line of the proper length to connect the water supply. They come in 9”, 12”, & 16” lengths. It is better to have one that is too long and loops rather than have it strained or, kinked. I do not recommend using the Watts Floodsafe closet connectors as I have seen some issues with them. I have seen them false trip and shut off the water supply to the toilet. But far worse I have seen a few that blew apart and caused a tremendous amount of water damage to the home. The connections on the braided stainless steel supplies are rubber gasketed and no Teflon tape or thread sealant is needed.
7.) At this point remove the cap of the overflow tube if there is one present. Insert the refill tube into the overflow tube and hold it in place with your right hand. While holding the overflow reach down with your left hand and turn on the water supply at the angle stop valve. The tank should fill to the water line marked on the tank or, overflow tube or, if there is no mark to 5/8” below the top of the overflow tube. Turn the water level adjustment screw until the water level is set properly. If the float hits the stops on the adjustment screw without the water level at the correct height the height of the valve is wrong. At this point the valve can no longer be turned to adjust height, so a different method is used. Turn the water back off at the angle stop valve. Pull the locking collar up towards the float. This releases the screw so the valve can be raised or lowered by pushing and pulling. When the correct height is reached push the locking collar back down to again secure the valve in place. Failure to do this will cause the top half of the valve to launch and a resulting geyser. Make sure the collar goes all the way back down into the locked position.
8.) Once the water level is set correctly pull the refill tube back out of the overflow tube. There are 2 ways to secure the refill tube to the overflow tube. The refill tube must fasten above the overflow tube and direct its flow into the tube. If the refill tube is down inside the overflow tube the water from the tank may siphon into the bowl causing the tank to keep refilling only to leak into the bowl again. The refill tube angle adapter can be used if there is room for the refill tube to feed it without stress or, kinking. Quite often I use the other method which is to remove the metal mounting clip from the angle adapter. The tube then goes over the round part of the metal clip and the clip secures to the overflow in the same manner. Trim the refill tube so it runs nicely without kinks of excessive loops.
9.) Check for leaks and proper flush. Place the lid back on the tank and cleanup!
As you can see this job is not difficult in most cases and if the fill valve was not shutting off can often save you hundreds of dollars on your water bill.
I had a flush valve leaking on my Mansfield toilet so that it would continually be filling up with water. So I replaced my toilet insides with a fluidmaster kit, flush valve and all. It works pretty good but I am having two problems:
1. It doesn’t seem to flush “all the way” – I sometimes have to hold down the lever for a while. I am working with the chain adjustment to correct his but haven’t yet got it right.
2. It fills back up VERY slowly. I cannot find an adjustment for this problem. Maybe I have a defective fill valve, even though it is new?
Any suggestions for correcting these two problems are appreciated.
Hi Dooley,
I’m sorry that you didn’t get in touch earlier about this toilet. Mansfield toilets use a unique flush tower design and normally it is a simple matter of snapping on a new rubber seal on the part of the flush tower that goes up and down or, a new seal ring that fits in a groove on the flush valve part that is stationary. Which one is needed depends on the model toilet you have.
Unfortunately many people these days are buying the Fluidmaster “Universal” toilet repair kit and replacing far more than they need to making a small project into a big one with bad results being the norm.
Depending on the age of your toilet it either flushes with 3.5 gallons or 1.6 gallons. I believe the kit you installed has an adjustable flapper where you can turn the rubber disc to change the amount of time it takes to close and the amount of water allowed into the bowl for the flush. This timing is influenced by the position of the hole on the side of the cone on the bottom of the rubber disc. Turning it to the side makes it slower and toward the front makes it fall faster.
The slow refill may be a defective fill valve but more likely it is some debris possibly part of the washer from the shut off valve lodged somewhere between the angle stop valve and the fill valve restricting flow. If the flapper is not closing properly it can also make a slow refill of the tank but you will see water going through the toilet.
I hope this helps you out.
In the future when you get into a plumbing project try researching it a bit first and you can probably save some time and money. A good place to go and ask questions is Terry Loves Forum. There are many Plumbing Pro’s and knowledgeable DIYer’s that will give you the information you need to avoid headaches.
I just replaced my fill valve with a new Fluidmaster fill valve. (I replaced our other toilet with one last week and it works great…this one is giving me issues.) I know that there is supposed to be some overflow trickle out the cap while the flushing/refilling is going on, but mine keeps leaking out after it is all finished. At first it was in 1-2 second spurts. I flushed the fill valve out really well for debris thinking that would help solve the problem. Now it’s a constant trickle after the flushing/refilling have ended. Do I need to replace the rubber washer in the cap? Or replace it with a complete new fill valve? Any suggestions would be wonderful!
Hi Becky,
Make sure that the valve parts under the top cap are locked in place properly.(with the water off of course)
Also check the height of the Fluidmaster 400A in relation to the top of the flush valve overflow tube.
This height allows proper function of the anti siphon valve.
I am a single mom trying to fix a toliet. Here is what happend I went to flush toliet. It would not flush. I pulled the cover off the tank and seen that there was only about 1/4 of the tank filled with water. The water was trinkling off the left side of the refill valve. Not where the water should come out. So I purchased a new refill valve. I shut the water off on the bottom of the tank when I went to unscrew the nut on the under side of the tank the whole refill valve would turn making it impossible to take off. So I decided I would do this another day. So when I went to turn the water back on the refill valve worked great it filled the toliet up. When I went to flush the toliet again, it did the same thing, would not fill up with water and just trinkled out of the left side of the refill valve. The only way the tank will fill up with water is when you shut the water off by the valve, then turn it back on, any suggestions very frustrated was told this was to be an easy job.
Hi Diane,
That is actually quite common thing for a Fluidmaster 400A to do when it needs replacing.
Each time you shut off the water and turn it back on you are good for one fill up.
I would replace the fill valve with another Fluidmaster 400 A, and when you do that also pick up a braided stainless steel supply line, and a new flapper as well. It will cost you less than $20 if you do it your self, and you should be in good shape for another 5 years or so.
Thanks for the comment.
Post back if you need any more help.
Redwood
I just installed my second fluidmaster 400A. They both flush and refill the tank but when flushing/refilling, one has water running out of the holes near the cap and the other one does not. Which one is working incorrectly and how can I fix it?
Hi Jeff,
That would be the Anti Siphon. I would check That the height or length of the 400A is set properly.
Thanks for posting hope this helps,
Redwood
I tried moving both of them up and down to see where the appropriate height was. Neither of them reacted differently. One contninued to have water come out of the holes and the other did not regardless of the height. Is the one with the water coming out defective? If I leave them both alone, will it cause any problems? Thanks for the help.
Hi Jeff,
It is normal for a small amount of water to come out from under the cap on the Fluidmaster 400A,
Make sure that the critical level mark is 1″ above the top of the overflow tube as shown in the bottom diagram in the above drawing.
Unsnap the cap on the top of the Fluidmaster 400A and make sure the valve mechanism is completely (turned) locked into place and snap the cap back on.
If these steps do not stop the water from coming out it is the “normal” dribble of water in my belief.
Redwood
Hi Jeff,
It sounds like it would be normal operation to me and should not be a problem.
Redwood
I have installed a fluidmaster 400 about 5 months ago it appears to be leaking from the fill valve below the locking collar. The critical level mark is 1 1/4 inches above the overflow tube, the tank fills from the refill tube until it is 1/2 inch below the overflow valve. The water stops flowing from the refill valve as the float rises but water continues to fill the tank from the shaft. I have taken this apart several times to check for debris and see noting wrong. Should I replace the fluidmaster I just installed?
Hi Ann
Yes I would replace it.
As inexpensive as they are if they don’t work right I replace them.
They actually do make a repair kit but fixing something that costs less than $10???
I hope this helps you out,
Redwood
I have an American Standard Lexington one-piece toilet that was installed around 1990. The inside tank height is about 10 inches. I installed the Fluidmaster 400A but I cannot place the Critical Level (C.L.) at least 1 inch above the overflow tube without the tank lid hitting the black top of the valve – it appears that the C.L. is barely above the overflow. Then I tinkered with the flexible hose angle to keep it from siphoning water from the tank. That did not work – even though the fill valve stops at 5/8 inches below the overflow tube, within 15-20 minutes the water level rises and trickles into the overflow tube. Does Fluidmaster or other manufacturer make a lower profile fill valve that can handle the short tank height withiout the siphoning problem?
Hi Jim,
Some of those low profile toilets like the American Standard Lexington & Hamilton are a real bear to get a Fluidmaster 400A fill valve working in.
It sounds like your 400A is not shutting off fully.
Try adjusting the height just shy of hitting the lid then adjust the water level by adjusting the float,
Using the clip that comes with the 400A for the bowl refill tube should stop the siphoning from the tank to the overflow by the fill tube but to me it sounds like the 400a isn’t shutting off properly.
If you can’t get it going properly the Am. Std. OEM fill valve part number is 738103-007A
Hope this helps,
Redwood