SERVICE INSTRUCTIONS
1. One way to determine if the Pressure Reducing Valve is
working is to carefully place your hand on the Reducing
Valve body. If the system is up to temperature but the
valve body feels cold to the touch, then it is passing
water. The problem may be an improper setting (see
action on Pressure Setting), a leak downstream, or a faulty
valve (which would need to be replaced).
2. If the relief valve discharges periodically, it is an indication
that the system may have lost its air cushion in the com-
pression or expansion tank. To determine if this is the
case, initiate the following test:
a. Bladder or diaphragm style pre-charged tanks: Shut off
boiler and allow system to cool to ambient tempera-
ture. Isolate the tank from the system, then bleed the
water from the tank. Place a tire-type pressure gauge
on the air valve on the tank. If the pressure is zero, the
cushion is lost. The absence of the cushion may be
from a leaking air valve. To check if this is the case,
add some air to the tank and place some liquid on the
valve stem area. If the liquid bubbles, the valve is leak-
ing and must be replaced (see Instruction Manual
A01500 for valve replacement). If the absence of the air
cushion was not caused by a leaking valve, then the
bladder or diaphragm is leaking, and the bladder must
either be replaced (for the “B” Series) or the tank must
be replaced (for the “D” Series). See Instruction Manual
A01500 for bladder replacement.
b. Conventional compression tanks: Shut off the boiler for
approximately 30 minutes. Record the pressure. Turn
the boiler on. If, within 8-9 minutes, the pressure gauge
at the boiler indicates a value within 10% of the relief
valve setting, then the tank is waterlogged and needs
to be drained and re-charged (see Instruction Manual
S10300 for drain and air-charge procedures).
3. If the Pressure Reducing Valve fails to fill to the set COLD
fill pressure, the strainer may be clogged. To service the
strainer, follow the following steps:
a. Verify that the city water or cold water shut-off valve is
closed.
b. Turn the boiler on-off switch to the “OFF” position.
c. Remove strainer nut located on bottom of reducing
valve.
d. Remove and clean or replace the strainer.
e. Reinstall the strainer nut with O-ring into the reducing
valve and tighten to a torque of 10 in-lbs. Min. – 100 in-
lbs. Max. Replace the strainer nut with O-ring if it is
damaged.
f. Close the boiler drain and open cold water shut-off valve
to refill system.
g. After system has been filled and vented, turn the boiler
on-off switch to the “ON” position and resume normal
boiler operation. Close the cold water shut-off valve.
Valve Repair
To service the valve using the repair kit, follow steps 1, 2 and
3 from above and these additional steps:
d. Remove the strainer.
e. Using a size 25 Torx screwdriver, unfasten the six
cover screws and remove the body cover. (A 1/8" Allen
wrench will work in an emergency, but stripping may
occur).
f. Remove the spring cap and spring.
g. Remove the hex nut by holding the stem assembly sta-
tionary while turning the nut counterclockwise. The
stem assembly may drop once the nut has been
removed.
h. Lift off the spring plate, diaphragm and valve plate.
i. Pull the rubber check valve from the valve body and
replace.
j. Insert new stem assembly into valve body through the
strainer opening in the housing. Hold in place.
k. Place the new valve plate, knob side down, on the
stem assembly.
l. Set new diaphragm on top of the stem, aligning holes
with those in the body.
m. Place spring plate over the diaphragm on top of the
stem assembly.
n. Thread the hex nut on the stem assembly. A dab of
Loctite (IMPORTANT! Any more than a dab will seize
the valve!) must be added to the hex nut before thread-
ing on the stem.
o. Place spring, spring cap and body cover on top.
p. Align body cover holes with those in the body and fas-
ten body cover screws.
q. Reinstall the strainer nut with O-ring into the reducing
valve and tighten to a torque of 10 in-lbs. Min. – 100 in-
lbs. Max. Replace the strainer nut with O-ring if it is
damaged.
r. Close the boiler drain and open cold water shut-off
valve to refill system.
s. After system has been filled and vented, turn the boiler
on/off switch to the “ON” position and resume normal
boiler operation. If pressure setting differs from previ-
ous setting, refer to section on pressure setting. Close
cold water shut-off valve.
WARNING: System fluid under pressure and/or at
high temperatures can be very hazardous. Before
servicing, reduce system pressure to zero or isolate the
pressure reducing valve from the system. Leave drain
valve open. Allow system to cool below 100°F. Failure to
follow these instructions could result in serious personal
injury or death and property damage.
WARNING: Do not use teflon tape when installing
the strainer nut with O-ring. The teflon tape provides
lubricity which can lead to overtightening and breakage.
Do not overtighten. Failure to follow these instructions
can result in moderate personal injury from hot water
and/or property damage.
WARNING: Corrosion or leakage are indications
that the Pressure Reducing Valve may be about to
cause serious damage from leakage or rupture. It must be
periodically inspected and if corrosion or leakage is noted,
the pressure reducing valve must be serviced or replaced.
Failure to follow these instructions could result in serious
personal injury or death and property damage.
3
WARNING: Do not use teflon tape when installing
the strainer nut with O-ring. The teflon tape provides
lubricity which can lead to overtightening and breakage.
Do not overtighten. Failure to follow these instructions
can result in moderate personal injury from hot water
and/or property damage.
