Fluidmaster 400 instructions

Check with Fluidmaster and see if they can help you.

https://www.fluidmaster.com/toilet/part-type/flappers/

First is the water overflowing the overflow tube? This would indicate that the ballcock or flow master needs a seal or that it is rubbing the side of the tank (if it is rubbing the side of the tank twist it slightly). If the water level is always below the top of the tube but the flow master keeps on filling in bursts then you need to replace the flapper. Flappers will decompose slowly and black residue will come off to the touch. Wear gloves because this black will be on your hands for days. The flapper gets a slight ripple or curve that allows water to get by.

Hi turtlerose07...

Sounds like you have one or two problems with the fluidmaster 400.
1...The float is set too high allowing the water to overflow into the overflow pipe and allowing your pump to run too much.
2...Flapper valve inside at the bottom of the tank is not sealing properly, thus allowing water to leak and causing the fluidmaster to keep trying to fill the tank with water and causing the pump to run too much.
Please take time to rate me

Flapper not seating properly,either get new flapper or try a old trick i've used shut off water to tank and drain tank then add hot water to tank and let set for a while sometimes that will soften and seat flapper it's worth a try it's free.

Hello- If you replaced old ball and rod set with new fluidmasters they will most likely need to be adjusted, not all toilet tanks are of equal height. You will have to adjust water height,meaning you must keep water level below fill tube located in center of the toilet tank. Adjustment is done from bottom of the fluidmaster, they screw in and out to adjust height. You will notice threads along the bottom part of the fluid master, on the inside of the tank,they adjust up & down! Goodluck!

if no leaks in tank. push down on flapper when it fills up. if water stops draining then it is the seal under flapper that is bad. you can lift up flapper and put patrolium jelly on bottom of flapper. this may just seal it. or it needs a certain type of flapper.

This indicated that there is dirt of corrosion in the flush valve assembly that get jarred loose and flushed out when turning on the supply valve below. My recommendation is replacing the flush valve assembly with a Fluidmaster flush valve. Be sure to follow the instructions when removing the old valve and installing the new one. If you need step by step instructions, please message me and I will provide them.

it is time to replace the flapper. turn water off, remove old flapper, wipe port off with rag where flapper seals, adjust chain to same length as old flapper, install new flapper. fluidmaster is the best brand.

Does it leak from the overflow? If so then the washer at the top of the Fluidmaster needs to be replaced. If it is not going over the overflow then you will need to replace the flapper on the flush valve.