CycleGard Intermittent Level Test Feature
To provide added protection to today’s smaller boilers, the CycleGard low water cut-off is equipped with
an Intermittent Level Test. This important feature adds protection against false signals that can be
caused by foam and volatile water conditions inside the boiler. The Intermittent Level Test removes
power from the burner at preset intervals. During the test, foam dissipates and the water level stabilizes
– allowing CycleGard to monitor the true water level in the boiler assuring safe and accurate operation.
The last four digits of the CycleGard model number determine the frequency and duration of the
Intermittent Level Test (ILT) as follows:
Last 4 digits Frequency Duration
of Model No. of ILT of ILT
1090 10 Minutes 90 Seconds
2090 20 Minutes 90 Seconds
When the optional SmartCycle feature is activated (see wiring instruction on previous page), the CycleGard’s test
time sequencing is restarted each time the burner fires. This feature enables a full burner run cycle (10 or 20 min-
utes, depending on model) prior to the first Intermittent Level Test.
OPERATING TEST PROCEDURE
1. After installation, bring the boiler water to a safe operating level, turn on
power and set the thermostat to call for heat. The amber LED lamp should be
off. The boiler will fire immediately.
2. Slowly lower the boiler water to a point below the probe. The amber LED
lamp on the control will light. The lamp may begin to flicker with the bounc-
ing water level. Stop draining the boiler when the lamp glows steadily. NOTE:
The water should not be lowered beyond a visible point in the gauge glass.
3. The boiler will shut down within 15 seconds.
IF BURNER DOES NOT SHUT DOWN IN LOW WATER
1. Check to see if a foaming condition in the boiler is preventing the control
from accurately detecting the water level. With power to the system on, and
water above the probe level, set the thermostat so there is no call for heat
and allow the burner to shut down. Then, slowly lower the water in the boiler
to a point below the probe. The amber LED lamp should turn on and the relay
will open after a 15 second delay. Once this has occurred, reestablish a call
for heat and the boiler should not fire. Now raise the water level to an operat-
ing level. The amber light should turn off and the control should reenergize
the burner circuit after a 30 second delay. If the control functions normally
during this test, but allows water to drop below the level of the probe when
the test is conducted with the burner on (as described in the Operating Test
Procedure above), the boiler is foaming. The CycleGard provides protection
for foaming boilers (see CycleGard Intermittent Level Test Feature above).
However, to provide optimal steaming performance, it is still recommended
that you clean the boiler in accordance with the manufacturer's instructions.
The foaming condition is caused by machining oils, elevated mineral content
from make-up water, grease and other contaminants in the boiler water.
Cleaning the boiler will eliminate foaming conditions in the boiler and provide
for optimal steaming performance.
2. Check terminal block wiring to insure that all connections are correct.
3. Check the probe installation to insure that there is 1/4" clearance from any
surface within the boiler or pipe. (Refer to Step 3 on page 1 of this instruction
sheet.
IF THE AMBER LED LAMP IS ON
The amber LED lamp indicates that the water is below the probe. If the gauge
glass shows that the water is at the correct operating level and the amber LED
is lit check the following:
1. Check for plugged gauge glass.
2. Make sure probe lead wire is properly secured to the terminal.
3. Check for proper ground between probe and boiler shell. Excessive use of
Teflon tape or sealing compound may isolate the probe from the boiler shell.
4. Remove probe and examine for oily residue. Clean probe with steel wool and
skim boiler.
IF THE GREEN LED LIGHT IS ON
The green LED lamp indicates that the control is conducting an Intermittent
Level Test. The burner does not fire during the test period. See Intermittent
Level Test Feature on this page for more details.
MAINTENANCE
To insure optimum performance, remove and inspect the probe annually. Clean any sediment or scale from the probe using a scouring pad or steel wool. Note: Do
not use caustic chemicals that could damage the probe. Reinstall the probe and perform the Operating Test Procedure described above.
OPERATING INSTRUCTIONS
NOTE: For proper low water cut-off operation, the boiler should be cleaned at initial installation and periodically thereafter. Refer to the boiler manufacturer’s
instructions for cleaning procedures.