The pressure switch is preset at the factory for activation
at 2 psi (14 kPa). Do not adjust the pressure switch if
the heater is installed more than 15 feet (4.57 m) below
the pool surface. Consult your local Jandy Pro Series
representative for recommendations.
Figure 34. Temperature Rise Measurement
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.