mp is in good condition, the plunger does
its work and the water is forced through into the boiler.

A clear sharp click of the valves at each stroke of the plunger is
certain evidence that the pump is working well.

The small drain cock between the horizontal checks is placed there to
assist in starting the pump, to tell when the pump is working and to
drain the water off to prevent freezing. When the pump is started to
work and this drain cock is opened, and the hot water in the pipes
drained off, the globe valve is then opened, and after a few strokes of
the plunger, the water will begin to flow out through the drain cock,
which is then closed, and you may be reasonably certain that the pump is
working all right. If at any time you are in doubt as to whether the
pump is forcing the water through the pipes, you can easily ascertain by
opening this drain cock. It will always discharge cold water when the
pump is working. Another way to tell if the pump is working, is by
placing your hand on the first two check valves. If they are cold, the
pump is working all right, but if they are warm, the cold water is not
being forced through them.

A stop cock should be used next to boiler, as you ascertain whether it
is open or shut by merely looking at it, while the globe valve can be
closed by some meddlesome party and you would not discover it, and would
burst some part of your pump by forcing water against it.

PART THIRD _________

It is very important when the pump fails to work to ascertain what the
trouble is. If it should stop suddenly, examine the tank and ascertain
if you have any water. If you have sufficient water, it may be that
there is air in the pump chamber, and the only way that it can get in is
through the stuffing box around the plunger, if the pipes are all tight.
Give this stuffing nut a turn, and if the pump starts off all right, you
have found the trouble, and it would be well to re-pack the pump the
first chance you get.

If the trouble is not in the stuffing box, go to the tank and see if
there is anything over the screen or strainer at the end of the hose.
If there is not, take hold of the hose and you can tell if there is any
suction. Then ascertain if the water flows in and then out of the hose
again. You can tell this by holding your hand loosely over the end of
the hose. If you find that it draws the water in and then forces it out
again, the trouble is with the first check valve.