Why my 300 fluidmaster won't let the toilet tank fill unless you slap the side of tank or turn a tap on

replace the inlet rubber washer

First shut water off at stop than flush all the water out of the tank next take a sponge and get all the water out of tank next unsrew the supply line from the valve under tank than move out of the way next unsrew the nut on the valve of fluidmaster than pull the fluidmaster out of tank stick the new fluidmaster in tighten nut srew the supply line back on turn on stop and let the tank fill up thats it if the fluidmaster dont shut off press the handle let some water out and adjust the fluidmaster screw Tip the water should stop a 1/4 inch below the flush valve tube in center of toilet

Use a fluid master universal fill valve, if it fits the tank. It will work as long as no part of the unit rests agains the side of the tank, if it does it will keep the float from rising.

Give it a slight turn to stop it from rubbing on the side

Plastic pieces inthere that give up after a while. I would go ahead and replace the assembly. But try this first,disassemble the top of the valve assembly and remove any debris. It could be the problem. There are rubber and

Hi!please kindly check your fill valve if it is working correctly.I thought the problem is in your fill valve.Kindly adjust the floater of your fill valve.

hiya:) This is a result of a very minor design error (i am a big fan of FluidMaster products) combined w/a slightly higher than normal water pressure situation or foreign matter stuck in the valve somewhere. try turning down the water pressure via the shuttoff under the toilet tank:)

The amount of water in any toilet bowl is determined by its construction and no tank adjustment will ever change that. American Standard has a history of having small water surface areas in their low or ultra low flush toilets. Take a large container of water and pour directly into the bowl. If the ending level remains the same, then that is the manufactured level for your toilet.

Not all tanks completely discharge all of the water when flushed. Measure 1.5 gallons of water into a container. Turn off your water supply to the toilet then flush normally. Replace the water in the tank with your premeasured amount and observe this new water level. You might be surprised to find it is at the same level it always is. Since water weighs more than 8 pounds per gallon, one concept used in todays toilets is to have more than 1.5 gallons of water in the tank and use the extra weight push the water past the flapper at a faster rate while designing the flapper to drop after only 1.5 gallons have passed through.

First thing to do is figure out if the problem is with the fluidmaster or with the shutoff valve. If the water doesn't run at all after flushing, then instead of cycling the shutoff valve, just loosen the nut where the supply tube attaches to the fluidmaster (under the tank). If the problem is in the fluidmaster, it will start to squirt out at you, otherwise it won't. Then you know what to disassemble and attempt to repair, or replace.