Toilet problems are concerning for several reasons. First, running water problems can cause a water bill to rise dramatically. Second, toilet tanks are noisy and distracting. Third, a broken toilet is not usable. Fortunately, following a series of refill valve inspections will fix many tank problems. The Fluidmaster refill valve, like most other refill valves, may appear intimidating, but is actually simple to restore to working condition.
Inspect the flapper if your toilet is continuously refilling without turning off. The flapper is the round rubber plug that lifts up and allows tank water to escape when you pull the toilet handle. A broken flapper will allow water to seep through and prevent the tank from filling to its proper level. Feel the flapper to see if it is damaged at all (e.g., cracks or large fissures that prevent the flapper from forming a tight seal). Also feel for calcium deposits that may prevent the flapper from resting in the proper position. Remove the flapper, clean under warm water and reattach.
Check the overflow pipe for cracks or leaks if the toilet continues to run after you have inspected the flapper. This is the white tube that stands directly above the flapper. Cracks in this tube will prevent the tank from filling properly and will cause intermittent refilling. If you find any damage, you must replace the overflow pipe.
Check the water adjustment clip in front of the float if Steps 1 and 2 do not stop the water from running. The water adjustment clip sets the water level in the tank. If set too high, the tank will continuously fill and reach the overflow pipe. Lower the adjustment clip to lower the tank water level.
Open the water valve to which your toilet is connected if the refill cycle is excessively noisy. A limited water supply from the valve can cause this problem, not the Fluidmaster.
Reposition the angle adaptor if the refill cycle is still noisy after opening the water valve. The angle adaptor is the plastic arm that rests above the overflow pipe. Sometimes the angle adaptor can obstruct water feeding into the pipe. Slightly tilting the adaptor so water flows down the entire surface of the overflow pipe will solve this problem.
Remove the top cap. Simply twist it counterclockwise if the refill valve does not operate at all. The Fluidmaster will not operate if the cap is not locked properly into place. Place the cap back on and twist clockwise until it is firmly in place. The Fluidmaster will turn on when the cap is properly positioned.