DIMENSIONS
OPERATING INSTRUCTIONS
NOTE:
Hydrolevel recommends that the boiler
manufacturer’s procedures for skimming the boil-
er be performed prior to placing the control into
operation.
1
After installation, raise the boiler water level
until water is in contact with the upper probe.
Turn on power and set the thermostat to call for
heat. The burner should fire immediately.
2
Using the boiler drain, slowly lower the water
level to a point below the lower probe. The
burner should shut down immediately upon a
low water condition.
NOTE:
The water should not be lowered beyond
a visible point on the gauge glass.
IMPORTANT:
If the burner does not shut down in
a low water condition, turn off power immediately
and refer to troubleshooting instructions below.
TROUBLESHOOTING
1
If the burner does not shut down upon water
falling below the lower probe: Remove power to
the burner and check installation. Check wiring
and make sure that burner is connected to the
fourth terminal from left on terminal (P2). If
wiring is correct, check to make sure the
probes are not falsely grounded. Voltage
between the probes and chassis ground should
be 120-140 VAC with water beneath both
probes. A lower reading may indicate a shorted
probe. Remove probes and check for contami-
nation.
2
If the burner will not fire with water at the top
probe: With a voltmeter and power applied at
terminals 2 and 1: Check the voltage between
the upper probe and chassis ground. Reading
should be 0-10 VAC with water at the upper
probe. A higher reading may be the result of
poorly conductive water or probe contamina-
tion. Remove probes and check for contamina-
tion. If the burner will still not fire after cleaning
probes, contact factory for assistance.
SERVICE / MAINTENANCE
The 724 Series Control requires regular
maintenance to ensure continued, safe oper-
ation. During normal boiler function, sedi-
ment may accumulate in the low water cut-
off's probe housing. If left unchecked, this
sediment can build up, trap water in the
probe housing, and prevent the control from
detecting a low water condition in the boiler.
A regular blow down of the control is
required for proper operation.
To flush the sediment from the chamber, the
control must be blown down throughout the
heating season in accordance with the fol-
lowing schedule:
• Daily for first week following control
installation
• Prior to heating season startup in the fall
• Once per week during the heating season
Instructions:
Confirm water is visible in the
gauge glass. If not visible, shut the burner
off, allow the boiler to fully cool, then add
water until visible in the gauge glass. Once
water is visible, bring your boiler back up to
temperature. With the boiler running, place a
heat resistant pail directly beneath the con-
trol casting blow down valve. Open the valve
and allow the sediment and water to drain
into the pail. Continue to drain the water
until it runs clean (One to two gallons is gen-
erally sufficient). Close the valve when com-
pleted. Replenish the water in the boiler if
needed.
REGULAR MAINTENANCE
REQUIRED.
Failure to
properly maintain the control can lead to
severe damage to the boiler, other property,
personal injury, or death.
To prevent serious person-
al injury from steam and
hot water, make sure there is a discharge line
from the blowdown valve to a proper place of
disposal. Failure to follow this caution could
result in personal injury.
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