Specifications

43
SECTION IX: MAINTENANCE AND SERVICE INSTRUCTIONS
A. MAINTENANCE OF LOW WATER CUT-
OFF DEVICES (when installed)
See Section XIV Appendix for LWCO Installation
Instructions
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1. PROBE TYPE LOW WATER CUT-OFF
Although these devices are solid state in their
operation, the probe is exposed to possible
contamination in the boiler water and subject to
fouling.
Provisions have been made on the supply manifold
on the boiler. Sometimes the LWCO can be found
in the primary loop of the boiler system. Ideally,
shut off valves have been installed between the loop
containing the LWCO and the rest of the system, to
minimize the amount of system draining.
It is important to physically remove the probe from
the lwco tapping annually and inspect that probe for
accumulation of scale or sediment.
Follow these steps to inspect, clean and/or replace
the probe:
a. Turn off electric service to the boiler.
b. Drain boiler water to a level below the tapping
for the probe.
c. Disconnect wiring connections between the low
water cut-off control and the probe.
d. Remove the low water cut-off control from the
probe.
tenacious lime deposits. The most stubborn
deposits may be removed from the probe by
using a diluted amount, 3 parts of water to 1 part
of phosphoric acid (H
2
PO
4
).
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h. Clean the pipe threads of the probe to remove
old, hardened pipe dope and other foreign matter.
i. Apply a moderate amount of good quality pipe
dope to the pipe threads on the probe, leaving the
two end threads bare. Do not use PTFE (Tefl on)
tape.
j. Screw the probe into the LWCO tapping.
k. Mount the low water cut-off control on the
probe.
l. Reconnect the control to probe wiring.
m. Fill the system with water.
n. Add boiler water treatment compound as needed
(refer to Paragraph B.).
o. Restore electric service to the boiler.
p. Fire burner to bring the water in the boiler to a
boil to drive off free oxygen.
q. WARNING — BEFORE RETURNING
BOILER TO SERVICE: Follow the low water
cut-off check out procedure in Section IX,
Paragraph I, No. 4.
B. BOILER AND SYSTEM CLEANING
INSTRUCTIONS FOR TROUBLE FREE
OPERATION
1. Filling of Boiler and System — General —-In a hot
water heating system, the boiler and entire system
(other than the expansion tank) must be full of water
for satisfactory operation. Water should be added to
the system until the boiler pressure gauge registers
12 psi. To insure that the system is full, water should
come out of all air vents when opened.
2. Boiling Out of Boiler and System. The oil and grease
which accumulate in a new hot water boiler can be
washed out in the following manner.
a. Ideally, shut off valves have been installed
between the boiler return manifold and the rest
of the system, to minimize the amount of system
draining.
b. Drain the boiler to a level below the relief valve
tapping.
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e. Unscrew the probe from the LWCO tapping.
f. Inspect that portion of the probe that is exposed
to the water for a scale or sediment buildup.
g. Light deposits may be removed by wiping the
probe with a damp cloth. Wiping the probe with
a cloth soaked in vinegar will remove more