Jandy LRZ Electronic - 7.8 Temperature Rise

Page 31
ENGLISH
Installation and Operation Manual
|
Jandy
®
Legacy™ Model LRZE Pool/Spa Heater by Zodiac
®
Make sure the pool lter is clean before making
any pressure switch adjustment. A dirty lter will
restrict the water ow and the pressure switch cannot
be adjusted properly.
To adjust the pressure switch, see Figure 22 and
proceed as follows:
1. Set the heater control to the "OFF" mode.
2. Remove the side panel above the front header to
access the water pressure switch.
3. Start the lter pump and conrm by means of a
voltmeter that the pressure switch closes (if the
switch fails to close, replace it with a switch that
has a lower minimum setting).
4. Set the heater control to either "POOL" or "SPA".
Heater should start.
5. With your ngers, turn the adjustment sprocket
very slowly clockwise until the heater goes off.
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 lter pump
OFF. The burners should shut off immediately.
If they do not, restart the lter 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 re unless the pump is running. If a
proper setting cannot be reached, contact the factory
service department.
 
 Atemperaturerisemeasurementkitisneeded
toperformthistest.orderpartnumber
R0336000.
The Legacy pool and spa heaters have an
internal bypass which accommodates a wide range of
water ow. The bypass is easily adjustable to change
the temperature rise for optimum performance and
length of heater life. The bypass assures constant heat
exchanger ow even though ow through the lter
system will vary depending on how dirty the lter 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 ow rate is known to exceed 125 gpm
(7.9 lps), an external bypass may be needed to assure
proper heater operation.
Water ow should be conrmed upon start-up of
the heater and in most servicing situations. If the ow
is not normal, corrections must be made to the pool
system. Flow is evaluated by determining the water
temperature rise through the heat exchanger.
Before checking the temperature rise, make sure
that the pool lter is clean and that gas supply and
manifold pressures are correct. If necessary, clean
all components of the lter system. Temperature rise
is measured in the return header of the Legacy. To
measure the temperature rise, turn off the lter pump
and remove the plastic plug protruding through the
cabinet on the return header side of the heater. See
Figure 23. With the plug removed, install the special
thread adapter and Pete’s Plug
®
tting and insert a
pocket thermometer. A temperature rise measurement
kit is available through your Jandy 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 specied in
Table 6, proceed as follows:
1. If the piping system has an external bypass valve,
close it.

SLOWLY TURN ADJUSTMENT
SPROCKET CLOCKWISE
UNTIL HEATER GOES OFF.

BYPASS
ADJUSTMENT
SCREW
THERMOMETERWITH
PETE'SPLUG
®