Water Pressure Switch Adjustment; Temperature Rise - Jandy Lite2 Installation And Operation Manual

Model LD Pool and Spa Heater
Figure 18. Pressure switch adjustment.

7.5 Water Pressure Switch Adjustment

CAUTION
The water pressure switch should be adjusted to turn
the heater off when the pump is off. Setting the
switch to close at too low of a flow can damage the
appliance. Adjust the switch to turn the heater off,
not on.
ATTENTION
Le manocontact de pression d'eau doit être réglé de
façon à ce que l'appareil cesse de fonctionner si la
pompe s'arrête. Si le manocontact est réglé pour se
fermer lorsque le débit d'eau est trop faible, l'appareil
risque de s'endommager. Réglez le manocontact
pour qu'il arrête l'appareil, et non pour qu'il le mette
en marche.
The pressure switch is preset at the factory for
activation at 2 psi (14 kPa). Adjust the pressure switch
only if any part of the filter system piping is 3 feet
(0.91 m) or more above the top of the heater jacket.
Do not adjust the pressure switch if the heater is
installed more than 15 feet (4.57 m) below or 6 feet
(1.83 m) above the pool surface. Consult your local
Jandy representative for recommendations.
On some installations, the piping from the heater
to the pool is very short. The back pressure could be
too low to trigger the pressure switch. If this happens,
it may be necessary to install a directional fitting or
elbows where the return line enters the pool. This will
increase back pressure enough for the heater to
operate properly.
Make sure the pool filter is clean before making
any pressure switch adjustment. A dirty filter will
restrict the water flow and the pressure switch cannot
be adjusted properly. To adjust the pressure switch:
1. Set the control panel rotary switch to the OFF
position (see Figure 17).
2. Set the POOL and SPA temperature controls to
the Max position.
3. Turn filter pump on. If a two-speed pump is
used, make sure it is at high speed.
NOTE: If using a two-speed pump, the heater should
not be allowed to fire on low speed.
4. Set the rotary switch to either POOL or SPA.
The heater should start.
5. Pry out the top rubber dust plug on the top of the
pressure switch.
6. Use a 7/32 inch (5.55 mm) Allen wrench to turn
the adjustment screw very slowly clockwise until
the heater goes off (see Figure 18).
7. Slowly turn the pressure switch adjustment
screw counterclockwise one-quarter turn. The
heater should come back on.
8. Check the adjustment by turning the filter pump
OFF. The heater should shut off immediately. If
it does not, restart the filter pump and repeat
Steps 6 and 7. Check the adjustment again.
9. Return the pool temperature control to the
desired temperature.

7.6 Temperature Rise

The automatic flow control valve (see Section
5.2) maintains the proper flow through the heater at
rates up to approximately 125 gallons per minute
(GPM) (475 liters per minute [LPM]).
A temperature rise test confirms proper water
flow through the heater. The temperature rise is the
difference between the temperature of the pool or spa
water before and after heating, as measured in the
header. Perform the following temperature rise test
when the installation is complete:
1. Make sure the pool filter is clean.
2. Set the rotary switch on the temperature control
panel (see Figure 17) to OFF.
3. Turn the filter pump OFF.
4. Remove the drain plug located on the inlet/outlet
header of the heater and replace it with a Pete's
plug (see Figure 14).
5. Insert a pocket thermometer (see Figure 14)
through the Pete's plug into the header.
6. Turn the filter pump ON and wait 3 minutes. The
heater remains OFF. This allows water from the
pool to reach the heater.
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