Installation Guide

PROBLEM POSSIBLE CAUSE OR CAUSES
1. Pressure creeps or builds up in system A. Thermal expansion of water as it is being heated.
above the setting of pressure reducing valve. B. Foreign matter on seating face of seal ring.
C. Cut, worn or chipped seal ring.
D. Cut or worn stem o-ring or worn o-ring groove.
SOLUTION
a. This is a natural consequence. It may happen each time that the heater runs. A pressure relief valve
or expansion tank must be installed. This will not prevent pressure rise but should limit it to a safe level.
b. Flush the reducing valve by opening one or two xture outlets wide. If this does not correct the problem,
remove seal ring for cleaning.
c. Replace with new seal ring. Temporary repairs may be made by turning the seal ring over.
d. Replace with new stem o-ring and/or cartridge.
2. Pressure and xture ow is unsteady. A. Low water supply pressure in mains caused possibly
by high area demand during certain periods of the day.
B. Heavy periodic demands by appliances in the house.
SOLUTION
a. This is a water department problem. It is due to the mains being inadequate for the demands made
on them.
b. House service lines may at times be inadequate for the load. Size of some pipelines may need to be
increased. Pressure setting of reducing valve may be too low.
c. Try increasing pressure before changing pipelines.
3. Small, inadequate ow from xtures. A. Pipelines to xtures may be too small or house main
supply may be inadequate for normal xture demand.
B. Heavy periodic demands by appliances in the house.
C. Screen clogged with debris.
SOLUTION
a. It may be necessary to increase pipe sizes only in some sections of the system leading to the
offending appliances or xtures. Increasing the house service mains might be necessary if small
supply is general at all xtures.
b. Raise pressure gradually by readjusting valve until this point is determined.
c. Clean screen.
4. Valve appears to be noisy; hums, whistles A. Hum or whistle is usually caused by a high velocity of ow
or chatters in pipelines causing vibration.
B. Chatter usually originates with worn seat washer or
loosely installed seal ring.
SOLUTION
a. Pipelines could be small or too light. Reducing valves could be too small. Pipes and valves being
small would accentuate this condition.
b. Inspect seal ring. If a deep channel appears on seal ring face, replace or use the opposite side.
c. Frequently noise appears in a faucet or appliance and seems to originate from the reducing valve.
There is a general tendency to use streamline piping of a relatively small size. Velocity is naturally
high and noise of fast moving water is not unusual.
Pipe lines in a water supply system must be of sufcient carrying capacity to maintain adequate pressure at the
most remote or highest xture. Under the maximum probable xture use, minimum adequate pressure is generally 8
to 15 lbs. but may be more, depending on the equipment being supplied. Relatively high service pressures which can
create high water velocities in pipe lines would allow use of smaller pipes to satisfy xture use. However, high velocity
tends to cause whistling and humming. Reduction of pressure by the use of a pressure reducing valve, in an attempt
to eliminate such a condition, may reduce pipe line capacities below that which is adequate for maximum probable
use. When high service pressures are in effect, either continuously or periodically, the application of a pressure reduc-
ing valve will be successful only when the installed pipe line is of adequate size to satisfy the system demand at the
lower pressure. When actual water demands are unknown, the valve size should be no less then the existing pipe size.
Troubleshooting
ISNR3XL (REV. E 7/17)
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
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