The fill valve in a toilet is the mechanism that allows water to flow back into the tank to prepare for subsequent flushes. Through regular use, these valves will eventually breakdown. Here are three things to look for that may indicate the fill valve is bad.
1 – Toilet Runs Constantly
This is a common signal that a toilet’s fill valve is broken. However, there are a few other things besides the fill valve that could cause the toilet to run so, first, look inside the tank. If the water is running over the fill valve and into the overflow hole, the float could be set incorrectly. Simply bend the arm of the float downwards so that the float will trigger the water shut off at a lower level. If this works, the fill valve is working fine. Next, look carefully at the chain that runs from the handle down to the flapper.
Occasionally this chain will become kinked and won’t extend far enough to allow the flapper to seal properly. This would mean the fill valve would run constantly since the water is escaping out of the tank as soon as it is pumped in. Finally, check the flapper. Much like the when the chain gets caught, if the flapper is the wrong size or will not sit correctly over the drainage hole, then the fill valve will continually try to fill up the tank. Try holding the flapper down to ensure the drainage hole is sealed and watch the water rise up to the proper height. If the float reaches its shut off point and the tank keeps filling, then the fill valve has gone bad.
2 – Toilet Won’t Flush or the Flush is Weak
A weak flush or no flush at all when the handle is depressed may mean that the toilet tank is not being filled with water properly. A weak flush may also be caused by a float shut-off that is set too low, so try bending the float arm upwards to confirm it is the fill valve first. No flush probably means the fill valve is broken or blocked and not sending any water to the tank.
3 – It Takes a Long Time For the Tank to Refill
If the toilet is taking an extraordinarily long time to fill after flushing, it may be because water is having trouble passing through the fill valve. Check for an easy to remove blockage in the valve before buying and replacing the whole thing.