Jacuzzi Z Builder Series Mechanics And Repair page 32

Chap Seven: Topside Control
There are several types of topside controls used on the Jacuzzi electronic spa.
One style uses a combination of jet button and temperature dial. More common
are topsides with digital readouts and various buttons.
HOW THEY WORK:
Topsides with a dial temp control simply work by resistance. Turning the dial up
or down changes the resistance that the board reads and either turns the heater
on or off.
The buttons on electronic topsides operate with piezo switches. They are simply a
crystal that when press creates a small voltage that travels down the wire to the
board. The board sees this impulse from the topside and responds. On some
models it's a step process; each time you press on the switch the board responds
going to the next step. On other models its simply an on/off response. (Example:
Press the air blower button on the topside and it turns the air blower on. Press
again and it goes off)
Topsides with a digital readout will have either a Liquid Quartz or Light Emitting
readout. They operate the same. The Liquid Quartz displays a quartz style
readout. The light emitting has light legs. Typically the higher end systems use
the Liquid Quartz.
The Platinum Series topsides are a liquid quartz readout with a light backlight. It's
the only topside Jacuzzi used with a liquid quartz. The remainder use a light
emitting diode or LED. Some have more function buttons than others. Jacuzzi
also used a topside with a Dial temperature control and a single jet button on
many of their Z series spas.