SERVICE / MAINTENANCE
The 711 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.
OPERATING INSTRUCTIONS
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 ter-
minal 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 contamination.
2
If the burner will not fire with water at the
top probe: With a voltmeter and power
applied at terminals G and H: 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 contamination.
Remove probes and check for contamina-
tion. If the burner will still not fire after
cleaning probes, contact factory for assis-
tance.
5
DIMENSIONS
NOTE:
Hydrolevel recommends that the boil-
er manufacturer’s procedures for skimming
the boiler 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 trou-
bleshooting instructions below.
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.
