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#2 Glycol Level Light, (plus #1) are ON
indicates.
A. LWCO switch (Fig. 21) is sensing sufficient glycol in
the reservoir and power is going through the switch.
B. There is no power going through the glycol flow switch
(Fig. 22). Check the following:
a. Is the pump (Fig. 6) still running? If not; Check
for 120 volts to the pump. If power is present but the
pump isn’t running, replace the pump.
b. Are all glycol circuit valves still open?
c. Are at least 1 fancoil or 2 ground thaw loops still
hooked up?
d. Check Y-strainer (Fig. 33) and clean if necessary.
e. Check all hoses for kinks or other restrictions.
f. Check that all quick couplers are fully engaged
and have snapped into position.
g. Check, with a multi-meter, for 120V in and out of
glycol flow switch (Fig. 22). If there is power in but not
out, replace the flow switch.
#3 Glycol Flow Light, (plus #1 & #2) are ON
indicates.
A. Glycol flow switch (Fig. 22) is sensing sufficient flow
and power is going through the switch.
B. There is no power going through the high temperature
limit switch (Fig. 23).
a. Check the setpoints on the high temperature
limit switch (Fig. 23) and digital operator (Fig. 10). If
these 2 set points are too close to the same, the high
limit temperature setting may have been reached and
the switch will be locked out. It will be necessary to
push the manual reset button on the front of the high
temperature limit switch and check the setpoints of
both the high limit switch (maximum 210ºF) and the
digital operator (maximum 10ºF lower than the high
limit).
b. With the high limit re-set and actual fluid
temperature well below the setpoint of both controls,
check, with a multi-meter, for 120V in and out of the
high temperature limit switch (Fig. 23). If there is
power in but not out, replace the limit switch.
#4 High Temp. Limit Light, (plus #1, #2 & #3) are ON
indicates.
A. Actual supply fluid temperature has not reached the
high temperature limit setpoint and power is going through
the switch.
B. There is no power going through the NC contacts of
the high pressure switch (Fig. 24). Blockage may have
occurred in the flue gas passage way.
a. Check the chimney pipe and rain cap for blockage.
b. Check the air tube connection to the pressure
switch and clean if necessary.
c. Clean the flue gas passages in the combustion
chamber (see Maintenance Section 6.1 G for
instructions)
d. Push the manual reset button on the pressure
switch and the circuit should be restored. If not
replace the switch.
#5 High Pressure Switch Light, (plus #1, #2, #3 & #4)
are ON
indicates.
A. Pressure in the combustion chamber and flue pipe
has not risen above the high limit cutoff point. power is
going through the NC contacts of the high pressure switch
(Fig. 24). Indicates no blockage in any of the flue gas
passages.
B. There is no power going through the digital operator
switch contacts (Fig. 10).
a. The actual supply fluid temperature may have
risen high enough that the Operator has cycled off. A
call-for-heat will be re-established once the Supply fluid
temperature has dropped to 5ºF below setpoint.
b. If the actual supply fluid temperature is well below
the setpoint of the operator (at least 10ºF lower),
check, with a multi-meter, for 120V in and out of the
operator. If there is power in but not out, replace the
operator and it’s sensor.
#6 Stat Light, (plus #1, #2, #3, #4 & #5) are ON
indicates.
A. The digital operator (Fig. 10) is calling for heat. The
burner should be engaged.
B. If the burner is not functioning, a fault lies within the
burner.
7.2 Burner Internal Faults
Diesel/Light Oil Burner
Below is a list of scenarios and possible causes for burner
failure.
A. The burner goes through the prepurge period normally.
The flame ignites, but the burner goes to lockout within
five seconds.
a. The phase/neutral lines are reversed. Correct
polarity is critical.
b. The wiring to ground is absent or ineffective.
c. The electric eye, light-sensing switch is dirty or
defective. Try cleaning the eye. If it still fails, replace
it.