Jacuzzi Z Builder Series Mechanics And Repair page 49

#1 and #2 CLICK and Pumps Come ON but no HEAT.
First step to isolate the problem is the pressure switch. To check, turn off power.
Identify the heater and the pressure switch screwed into the heater. It has 2 wires
coming out of the switch.
Take a short piece of wire and strip the ends of the wire. Disconnect the 2 wires
and place the wires in an accessible locale. Turn on power. Once the pump
automatically comes on, place the short piece of wire into both ends of the
pressure switch wire. This is going to tell the board there is water movement and
it can turn the pump on.
If you here a CLICK, the heater light or Icon should be ON. If so, you have
focused the problem as the pressure switch.
Now you might think, "I'll just leave this short in and bypass the switch altogether.
I probably don't even need it." Good thought; won't work. What the board will do
is catch your short. When the water reaches temp and turns the #1 pump off, it
immediately looks at the switch to make sure it's now open (your wire has made it
constantly closed). If it's not open, it will go into failure mode and either give you a
solid FL or FLO or the heater light will flash (depending on model of spa). The
spa will not start until it resets and you usually have to manually power up the
spa.
Real Solution:
a. You can try to adjust the pressure switch. This will work sometime. FIRST, turn
off main spa power. On most brands of pressure switches you can adjust them.
Again, usually you can turn the adjustment wheel. Some models have a metal clip
or piece of tape holding the wheel in place. Others use a gate you slide up and
then you can adjust. Usually once the adjustment wheel is free you turn the wheel
one full turn clockwise. That may solve the problem. If you turn it too far, the
result will be the pump will come on but the heater will not. So try turning only one
turn.