Specifications
Installation and Operation Manual
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Legacy™ Model LRZM Pool/Spa Heater
• Correct type of gas supplied
• Correct gas supply pressure
• Correct gas burner pressure
• Correct orice size
• Air in the gas line
If the main burners will not stay lit after checking
the items listed above, the gas valve may be causing
the fault. Replace the gas valve.
The pilot generator generates a 700-750mVDC
signal when heated by the pilot ame. When the pilot
generator is connected to the heater's control compo-
nents, there will be some voltage drop in the circuit so
that the measured voltage will be less than 750mVDC.
But the measured voltage should never be below
500mVDC when the ON/OFF switch is in the "OFF"
position or 220mVDC when the ON/OFF switch is in
the "ON" position.
With the pilot generator connected to the gas
valve and the ON/OFF switch in the OFF position,
place the red lead of the voltmeter on the TPP termi-
nal (test point 1) of the gas valve. Place the black lead
of the meter on the TPP/TH terminal (test point 2) of
the gas valve. The meter should show a minimum of
500mVDC. If the meter show less than 500mV, check
for partial shorts, loose or corroded connections or
partially broken wires between the pilot generator and
the gas valve.
If the wires and connections are sound, check the
pilot generator output. You will need alligator clips
to do this. Disconnect the pilot generator from the
gas valve. The pilot will go out. Light the pilot while
pressing down on the gas valve control knob. Continue
holding the knob for at least one (1) minute. Immedi-
ately measure the voltage between the two (2) wires of
the pilot generator. If the meter does not show at least
700mV, replace the pilot generator.
Check the voltage going to the safety circuit. Be
sure that the pilot generator is correctly wired to the
gas valve, the pilot is lit and the control knob on the
gas valve is in the "PILOT" position. Leave the red
voltmeter lead in place at test point 1. Touch the black
lead of the meter to the terminal of the roll-out switch
(fusible link) where the white wire from the gas valve
is connected (test point 3).
If no voltage is detected at test point 3, the wire
between the gas valve and the roll-out switch (fusible
link) is broken. Replace the wire.
If there is a minimum of 220mV at test point 3,
move the black meter lead to the other terminal of the
roll-out switch (fusible link) (test point 4).
If no voltage is detected at test point 4, the
roll-out switch (fusible link) has failed. This indicates
higher than normal temperatures in the component
compartment (vestibule). Normal component compart-
ment temperature is well below 148.9°C (300
o
F).
The roll-out switch (fusible link) is designed to fail
at temperatures above 151.7°C (305°F). Excessive
temperature might be due to a blocked ue or heat
exchanger. Clean the heat exchanger and clear the
ue and vent of any restrictions. Sometimes the roll-
out switch (fusible link) fails due to ame roll-out.
Flame roll-out may be caused by delayed ignition or
downdrafting in windy areas. Thoroughly investigate
the causes for ame roll-out and correct the problem
when replacing the roll-out switch (fusible link).
Check the voltage going to the vent temperature
limit. Leave the red voltmeter lead in place at test
point 1. Touch the black lead of the meter to the termi-
nal of the vent temperature limit where the white wire
from the roll-out switch (fusible link) is connected
(test point 5).
If no voltage is detected at test point 5, the wire
between the roll-out switch (fusible link) and the vent
temperature limit is broken. Replace the wire.
If there is a minimum of 220mV at test point 5,
move the black meter lead to the other terminal of the
vent temperature limit (test point 6).
If no voltage is detected at test point 6, the vent
temperature limit has failed. The vent temperature
limit will fail due to abnormal temperatures in the vent
system. Excessive temperatures will cause the switch
to open.
The vent temperature limit is designed to fail
at temperatures above 464°F (240°C). Excessive
temperatures can be cause by inadequate water ow
or a damaged heat exchanger. Thoroughly investigate
the causes for vent temperature limit switch failure and
correct the problem when replacing the vent tempera-
ture limit.
Check the voltage going to the external device.
Touch the black lead of the meter to the reman switch
terminal strip where the white wire from the roll-out
switch (fusible link) is connected (test point 7). The
meter should read at least 220mV. If the voltage is
less than 220mV, there may be a bad connection or
wire between the roll-out switch (fusible link) and the
terminal strip. The wire may need to be replaced. If
voltage of 220mV or more is detected at test point 7,
move the black lead of the meter to the reman switch
terminal strip connection where the white wire from
the high limit is connected (test point 8). The meter
should read at least 220mV. If there is no voltage, the
time clock switch or other external interlock may be
mis-adjusted, mis-connected or defective. Correct this
external problem.