Flush Tank Problems
Several problems can develop:
-Tank continues to run after tank fills
-Tank doesn’t fill but water continues to run
-Tank partly empties
-Water leaks on the floor
-Nothing happens when you push the flush handle
-No water pressure available
1. Procedure if water continues to run after tank
The problem is the water inlet valve is not seating
tight enough to shut the water off.
To isolate the problem, remove the tank lid. Grab the
float and lift:
a. If the water stops running the problem is in the float
mechanism. If the float is over halfway submerged look for a
leak in the float. Check the float and repair or replace.
If the float is okay, adjust the float downward. This can
be done by: (a) adjustment screw on top of the ball cock or
(b) bending the rod supporting the float. The
recommended water level is often marked on the tank wall.
If not, the water level should be about 1″ below the
b. If you cannot stop the water flow by raising the
float, the problem is probably the inlet valve in the
Shut off the water to the tank by turning the valve
below the tank or by closing the valve in the main supply
to the house. Remove the float assembly by unscrewing
two thumb screws. This will allow you to lift the valve.
In other ball cocks, unscrew the two thumb screws on
either side of the top assembly and lift it off. The
valve assembly should drop out.
c. Replace the rubber washer in the bottom of the valve.
If you do not have a new washer turn the old one over as
a temporary repair until you can get a new replacement.
Check the size before you reassemble.
Also, check the gasket or “O” ring toward the top of
the valve. This should be pliable so it will prevent the
incoming water from squirting out around the top of the
Reassemble the valve and turn on the water.
2. Procedure if tank doesn’t fill but water continues to
a. The problem is most likely that the tank ball is not
seating. Check to see if the linkage is binding or
hooked so it does not let the ball go completely down.
Or the tank ball might be so old it is wrinkled or
cracked so water is running through the tank ball.
b. The solution is to buy a new rubber tank ball and/or a
new linkage and replace the old worn parts. You might
consider replacing the entire tank ball and linkage with
a flapper valve.
c. Due to use, water, and salt deposits, the flush
handle might bind and not let the tank ball reseat. Put a
few drops of penetrating oil on the handle just inside
the tank and wiggle it back and forth. If the handle is
rusted so badly it cannot be loosened with the oil a new
one will have to be installed. To do this, remove the nut
inside the tank. This is usually a left hand thread so to
loosen you would turn clockwise.
3. Procedure if water leaks on the floor: water on
the floor underneath the toilet tank may be
caused by one of the following:
a. Condensation on the outside of the tank due to cold
temperature of the water. This will almost always happen
in the summer, when the temperature and humidity are
high. In the winter it will not occur.
A solution to the problem might be:
– Buy or sew a jacket for the outside of the tank which
acts as an insulator. Wash it frequently, to keep it
– Kits of insulation material can be purchased to
install on the inside of the tank. These require
considerable effort because the inside of the tank must
be dry and clean. The insulation must be installed so
water cannot seep between the insulation and the tank
– A valve can be purchased which will proportion a
fixed amount of hot and cold water into the tank to make
the water temperature high enough to prevent
condensation. This requires an alteration to the plumbing
system but is very effective. It will “waste” heated
– Buy a tray which hangs under the tank, usually hooked
to the top of the tank with thin metal strips. Put
sponges on the tray to soak up the water dripping on to
b. A leak in the water pipe to the tank. The water
leaking from this source will usually be in a puddle
under the end of the tank where the water pipe connects
to the tank. Look under the tank and see if there is an
accumulation of salts around the pipe.
Often times a one quarter or one half turn on the
nut next to bottom of the tank or on either side of the
shut-off valve (if there is one) will stop the leak.
If tightening the nut does not stop the leak it is
probably the gasket at the bottom of the “ball cock”
where it goes through the tank.
To do this, disconnect the water pipe to the ball
cock after dipping out water. Loosen the big retainer nut
under the tank and remove the “ball cock” assemble.
Replace the rubber gasket and reassemble the unit.
c. The refill tube may be misdirected so it directs the
water against the top or side of the overflow pipe
causing it to splash against the top of the tank and
running down the outside of the tank. If this happens
when you take the top off, readjust to direct water down
the filler tube.
The packing or “O” ring on the inlet valve may be
worn so when the toilet is flushed and the valve is
opened the water squirts out the top of the “ball cock”
against the tank top and runs down the outside of the
The procedure for replacing this packing is the same
as for replacing the valve seat.
4. Procedure when tank partly empties: sometimes when
you pull the flush lever the tank
partly empties or the handle must be held down to
completely flush the toilet.
a. Check to see if the mechanism or chain connected to
the rubber tank ball is free and not kinked. If so,
adjust the length so the rubber tank ball is lifted
higher when the flush valve is released. This will allow
more time for water to enter the stool.
5. Procedure if nothing happens when flush handle is
pushed: after many years of use the linkage between the
handle and the float wears out and becomes disconnected.
a. Remove the tank top and find out which part is worn
out. Replace it with a new part which can be purchased at
most stores selling plumbing supplies.
Temporary repairs can be made with a wire or cord if a
new part cannot be obtained for several days.
6. Procedure if there is no water pressure:
when the water pressure is gone the flush tank will
not fill for the next flush. All that is needed to flush
the tank is a big rush of water in the stool so a pail of
water dumped into the stool will flush it. Then part of a
pail of water must be poured in for the next use.
Installing A Ball Cock
When installing a new ball cock, make sure it is an
anti-syphon ball cock to meet code requirements. This type
of ball cock guards against contamination of the fresh
New types of ball cocks:
1. Diaphragm ball cock
a. Install the ball cock in the same way as conventional
models. Follow the directions that come with your ball
b. If the water supply contains a high level of minerals,
the moving-parts of a diaphragm ball cock should be
c. After several years of use, the diaphragm and valve may
need to be replaced. These parts are available as a kit
from a plumbing-supply store.
2. Float-cup ball cock
a. To install the float-cup ball cock just follow the
procedure for a conventional ball cock. The float ball and
rod arm are eliminated on this ball cock.
b. An adjustable sliding clip permits setting of tank