Chap FIVE: Pressure/Flow Switches
PRESSURE SWITCH
How It Works: The lower chamber of the switch is physically attached to the water
flow of the plumbing system. The pressure internal to the plumbing is also
manifested in this chamber. This chamber expands to push a post toward a
microswitch. When the chamber is not pressurized (pump off) the post pulls back
and the microswitch opens. When the pump is turned on the post pushes out and
closes the microswitch. The distance between the post and microswitch can be
adjusted on most switches. Typically turning the adjustment wheel clockwise
moves the post closer to the chamber and further from the microswitch. Turning
the wheel counterclockwise gives the opposite result.
What it Does: The purpose of the pressure switch is to notify the board whether
enough water is moving past the heater element. If sufficient pressure closes the
microswitch, the board turns the heater on. Otherwise it does not . Due to the low
pressure of Jacuzzi pumps 2 speed pumps should use a 1lb pressure switch. 2
pump, single speed pumps should use a 2 lb pressure switch. Overtime the
microswitch can fail, the post is less responsive, or doesn’t withdraw fast enough.
Any of these failures will cause the board to fail.
REPLACEMENT:
F106/7, F108/9, H136/276
Replacement of the pressure switch is easy. The pressure switch screws into the
heater assembly. Looking at the control box and heater (the steel tube), on the
left backside is where the pressure switch is.
You can change with water in the spa. You must work fast. First, put Teflon tape
or plumber’s putty on the threads of the new switch.
Turn off main power. Unplug the 2 wires from the old switch. Take an open end
½” wrench. Note on the top of the threads a ½” socket is available for your ½”
wrench. Loosen. Switch old with new. Tighten to snug. There is no direction to
end at. Plug the wires into the switch.
Summary of Contents for Z Builder Series
Page 43: ...balanced and not using too much or too little chemicals...
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