|The ONLY active component in
this spa side control is the thermostat. The light indicators, air
push-buttons, and thermostat have nothing to do with each other; it is simply a
conglomeration of 3 different functions in 1 box. Meaning, that if your
indicator lights fail, and the thermostat gives out, the air buttons will still
continue to activate the air switches in the spa control box.
(If your side control has an
electronic thermostat, then the blower indicator (orange wire) will not be used
for a blower light. See the electronic version of this control online for
details (-available soon-)
1. The air push
buttons. They send air pressure through the tubes to activate and
deactivate the air switches in the spa control. These air buttons simply
allow for electrical isolation between the user in the hot-tub or spa, and the
control system. They do NOT affect the thermostat's operation or the
2. The indicator
lights. The indicator lights are simply neon bulbs. These
can be found at Radio Shack, or techamerica.com. Usually, when you
disassemble one of these control boxes, the "Ready" indicator will be
very black, and the "Heat" indicator will be running a close
second. Since neon bulbs effectively "short-out" when power is
applied to them, current limiting resistors are used in series with them.
This is the primary difference between a 115V version of a spa side control
versus a 230V type. The resistors will be a higher rating on a 230V
control, to prevent burning out the neon bulbs.
The way that the indicator
lights work is that the air switch, or relay in the control box, sends
power back to the side control, to either the jets or the blower
indicator lines. This will be the yellow wire for jets, and orange
wire for the blower. This is the de-facto standard in this
thermostat. The thermostat is a single pole, double throw switch
(SPDT), activated by pressure effects in the sensing bulb. When the
pressure in the bulb is reduced (a cooler condition), the switch activates,
sending power to the N.O. or "normally open" terminal on the
switch. This will have 2 effects on the control.
When the temperature gets to its
high point, the switch in the thermostat will revert to the N.C. or
"normally closed" position. This, is the opposite condition.
What happens is that the thermostat will...
- It will send a voltage signal
to the spa control, (usually 115 or 230V), telling the spa control that it's
time to get the heater turned on. Using relays, this also turns on the
low-speed pump, or the main pump in low speed mode. (Not all control
systems use the same method).
- It will also send voltage to
the "Heat" light on the spa side control, telling the user that the
heater has been told to get the spa warmer. (But this does NOT mean that the
spa is actually doing this!)
- Remove the "call for
heat" signal to the spa control system, which turns off the heater, and if
not in the filter mode, it will turn off the spa pump motor if it is operating
in low-speed mode.
- Revert to sending voltage to
the "Ready" indicator on the spa side control, telling the user that
the set temperature has been reached.
The spa heats up to 98 degrees
(F), but won't go higher. I used to be able to get it up to 104 or 105
cases, this can be resolved by resetting the set screw in the thermostat
itself. Here are some ideas
on solving this problem. This usually occurs because the capillary
tube and the copper sensor has weakened over time and has expanded a small
amount, causing the "top end" of the thermostat's setting to be lower
than what was originally set by the factory.