INSTALLATION, OPERATION AND MAINTENANCE MANUAL
Easco Boiler Corp 1175 Leggett Ave Bronx, NY 1047 T: 718.378.3000 F: 718.378.4560 [email protected] easco.com
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5.5 Water Level Controls
Water level controls are essential to the safe operation of a Boiler. Depending on the
application, they indicate water level (gauge glass), control the starting and stopping
of a boiler feed pump secure the burners if water level gets dangerously low. Though
often neglected, they need regular attention to ensure smooth and safe operation. They
should be blown down daily to ensure the float chamber remains free of foreign matter.
When blowing down, the level in the gauge glass should be observed and the feed
pump control function and low water cut-off function tested as well.
5.6 Maintenance of Low Water Cut-Off Devices
NOTE: Probe and float type low water cut-off devices require annual inspection and
maintenance.
5.6.1 PROBE TYPE LOW WATER CUTOFF – Although these devices are solid state in
the operations, the probe is exposed to possible contamination in the boiler water and
subject to fouling. It is important to physically remove the probe from the boiler tapping
annually and inspect that probe for accumulation of scale or sediment.
Follow these steps to inspect, clean and/or replace the probe:
1) Turn off electric service to the Boiler.
2) Drain boiler water to a level below the tapping for the probe.
3) Disconnect wiring connections between the low water cutoff control and the probe.
4) Dismount the low water cutoff control from the probe.
5) Unscrew the probe from the boiler tapping.
6) Inspect that portion of the probe that is exposed to the boiler water for scale or
sediment buildup.
7) 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 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 (H2 PO4).
CAUTION!
Exercise caution when handling phosphoric acid and follow the instruction
label on its container.
8) Wire bushing of the probe is not recommended.
9) Clean the pipe threads of the probe to remove old hardened pipe dope and other
foreign matter.
