Model LJ Pool and Spa Heater
Page 43
Switch”. If there is no problem with the pool system or
pressure switch adjustment, replace the pressure
switch.
If test point E shows 24V, move the free lead of
the meter to the safety circuit of the six pin connector
where the black wire is attached at the lower right
corner of the connector (test point 8). If there is no
voltage at test point 8, then the connection from the
pressure switch to the power distribution board is bad.
Replace the six pin connector.
10.4.3.7 Gas Valve Voltage
Check the voltage going to the gas valve. Leave
the black voltmeter lead in place at test point 2. Touch
the free lead of the meter to the gas valve terminal
where the brown wire is attached at the center
position of the right side of the connector (test point 9).
This test point will have voltage present only during a
trial for ignition or during normal operation. The meter
should read 20-28 volts. If there is no voltage, there
may be a bad connection on the power distribution
board and the board may need to be replaced.
Listen closely to the gas valve when it is first
energized (24V first appears at test point 9 during the
trial for ignition). There should an audible "click" when
the valve opens.
If there is voltage at test point 9, but the gas
valve does not open, replace the valve.
WARNING
The igniter and some terminals of the power
distribution board utilize 115V or 230V power
and require appropriate servicing precautions.
Note that wires and terminals of these
components may be “hot” or "live" even when
the component is not operating.
AVERTISSEMENT
Le dispositif d’allumage, le circuit d’alimentation
électrique et certaines bornes de la commande
d’allumage utilisent une tension de 115 V ou de
230 V et exigent des précautions appropriées
lors du service d’entretien et de réparation.
Notez que les fils et les bornes de ces
composants peuvent être sous tension
même si le composant ne fonctionne pas.
10.4.3.8 Igniter/Ignition Control
With the igniter leads connected to the terminals
on the power distribution board there will be voltage of
98-126 VAC between test point 10 and test point 11 if
the heater is connected to a 115V supply. When the
supply is 230V, a regular voltmeter will read only 49-
64 VAC because of the way that voltage is reduced
by the power distribution board. However, a true
reading can be obtained by using an RMS voltmeter if
one is available. When using an RMS voltmeter, a
reading of 98-126VAC is expected. This voltage will
be applied only when there is an attempt to ignite the
burner or when the ignition control’s flame sensing
system has determined that it is OK to allow burner
operation. Even if voltage has been confirmed at the
end of the safety circuit, the “trial for ignition” se-
quence is imposed by the ignition control. This se-
quence consists of a 15 second period of pre-purge, a
10 second period for heat-up of the igniter and a 12
second trial for ignition. During this last 22 seconds
there is voltage between test point 10 and test point
11. If satisfactory ignition is not achieved, the igniter is
turned off and the system waits for a 45 second post-
purge period. The system may go through this cycle as
many as three times, but thereafter it is “locked out”
by the ignition control. Additional attempts will be
made only if the call for heat is interrupted by turning
off electrical power or setting the LJ controller to
'OFF' and then back to 'POOL' or 'SPA'.
To troubleshoot the ignition control, connect the
voltmeter leads at test points 10 and 11, and set the LJ
controller to call for heat. Observe that the normal
ignition sequence takes place. After the 15 second
prepurge, note the voltage between test points 10 and
11. Then look for the glow of the igniter by placing a
mirror on the bottom of the burner tray. If voltage does
not appear between points 10 and 11 during the trial
for ignition, replace the power distribution board.
If the correct voltage is detected between points
10 and 11 during the trial for ignition but the igniter
does not glow, check the connections to the igniter.
Disconnect the igniter wires from the in-line fuse
harnesses and the fuse harnesses from the power
distribution board. Using an ohmmeter, check each
fuse and harness for continuity. If the ohmmeter reads
an open circuit, the fuse has failed. The fuses are in
place to protect the power distribution board in the
event of an igniter short circuit. If either of the fuses
has failed, replace the igniter before replacing the
fuse.
If the fuses are intact, check the igniter with the
ohmmeter. Place one lead of the meter on each wire
of the igniter. The resistance should read between 25
and 300 Ohms, depending on the temperature of the
igniter. If the meter reads outside of this range or
shows an open or short circuit, replace the igniter.
To Next Page
Loading...
Need help?
General
