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Page 36
ENGLISH
Jandy
®
LXi
™
Model Pool and Spa Heater by Zodiac
®
|
Installation and Operation Manual
6. Slowly turn the pressure switch adjustment
sprocket
counterclockwise
one-quarter turn. The
heater should come back on.
7. Check the adjustment by turning the filter pump
OFF. The burners should shut off immediately.
If they do not, restart the filter pump and repeat
Steps 6 and 7. Check the adjustment again.
8. Return the pool temperature control to the desired
temperature.
It may be necessary to repeat these steps to get a
proper setting. The switch must be set so that the heater
will not fire unless the pump is running. If a proper
setting cannot be reached, contact the factory service
department.
7.8
Temperature Rise
The LXi pool and spa heaters have an internal by-
pass which accommodates a wide range of water flow.
The bypass is easily adjustable to change the tempera-
ture rise for optimum performance and length of heater
life. The bypass assures constant heat exchanger flow
even though flow through the filter system will vary
depending on how dirty the filter is.
For most installations, an external bypass valve
is not needed in the heater water piping. This is due to
the large size of the heater's internal bypass valve. If the
pump flow rate is known to exceed 125 gpm
(7.9 lps), an external bypass may be needed to assure
proper heater operation.
Water flow should be confirmed upon start-up of
the heater and in most servicing situations. If the flow
is not normal, corrections must be made to the pool
Figure 34. Temperature Rise Measurement
BYPASS
ADJUSTMENT
SCREW
THERMOMETER WITH
PETE'S PLUG
®
system. Flow is evaluated by determining the water
temperature rise through the heat exchanger.
Before checking the temperature rise, make sure
that the pool filter is clean and that gas supply and
manifold pressures are correct. If necessary, clean all
components of the filter system. Temperature rise is
measured in the return header of the LXi. To mea-
sure the temperature rise, turn off the filter pump and
remove the plastic plug protruding through the cabi-
net on the return header side of the heater, see Figure
34. With the plug removed, install the special thread
adapter and Pete’s Plug
®
fitting and insert a pocket
thermometer. A temperature rise measurement kit is
available through your Zodiac distributor. See
Section
11
of this manual for the correct kit number.
The internal bypass can be adjusted by means of
a screw on the right-hand side of the header. To adjust
the temperature rise to within the ranges specified in
Table 8, proceed as follows:
1. If the piping system has an external bypass valve,
close it.
2. Set the heater's control panel to the "OFF" posi-
tion.
3. Start the filter pump.
4. After three minutes, note and record the ther-
mometer reading. This is the pool water tempera-
ture.
5. Start the heater by setting the control panel to
either
POOL
or
SPA
. Allow the heater to operate
for 5 minutes or more. Note and record the ther-
mometer reading. Subtract pool water tempera-
ture from this reading. This difference is the tem-
perature rise. Refer to Table 8. If your measured
temperature rise is within the range designated for
your heater, skip steps 6 through 8.
Figure 33. Adjustment of Pressure Switch
SLOWLY TURN ADJUSTMENT
SPROCKET CLOCKWISE
UNTIL HEATER GOES OFF.