P/N 472091
6
Rev. B 4-16-02
Knob Stopper
Screw A
D.
OPERATION
Dual Temperature Control System
For convenience and economy all MiniMax NT heaters are
equipped with two thermostats on the front of the heater
control panel; see Figure 1.
THERMOSTAT KNOB STOPPER
Each thermostat is equipped with a mechanical stop that can be
locked or unlocked with use of a screwdriver to prevent
temperatures in excess of that desired by the user; see Figure 4.
The maximum setting can be adjusted by loosening the screw "A"
and turning the stopper dial to desired maximum setting. Lock the
setting by tightening the screw. The Mechanical stop is under the
knob. Ensure that the knob is stopping at the correct position when
the knob is rotated clockwise from a lower temperature position.
(See Thermostat Adjustment.)
NOTE
To eliminate error due to piping heat losses,
measure pool temperature with an accurate
thermometer directly at the pool or spa.
THERMOSTAT ADJUSTMENT
The knob with locking feature eliminates the need for constant
thermostat adjustments. Set the knob pointer to the desired pool
or spa temperature.
If further adjustment is needed, rotate the knob until the desired
temperature is obtained. This knob position corresponding to
your desired maximum pool or spa temperature may now be
preset (locked) by the knob stopper which prevents the knob
from being turned beyond the maximum temperature you set.
Figure 4.
INDICATOR LIGHT DESCRIPTION
The MiniMax Pool Heater provides nine status indicator lights, six can be seen from the front of the control panel which help you
understand the operation of the heater. If something should go wrong, the lights will aid in troubleshooting the problem. Three
additional lights can be seen after opening the control panel. These three lights give the service technician advanced troubleshooting
capability. All the LED lights are green with the exception of the red service LED.
POWER LIGHT (POWER)
The light is on at all times, in any switch position, indicating 24
VAC power is being supplied to the control circuit. If it fails to
light, no other light will be on. Possible causes are: a) external
power to the heater is disconnected, check service panel circuit
breaker or fuses; b) local circuit breaker inside the transformer
has tripped -- investigate cause before resetting; c) transformer
has failed.
THERMOSTAT (TSTAT)
This light is on when the thermostat contacts close, signaled by
the water temperature falling below the setpoint, calling for the
heater to fire to maintain the desired water temperature.
AUXILIARY (AUX)
This light is on when it indicates the remote switch contacts are
closed. This allows you to observe if your remote switch is
properly closing the heater control circuit. When shipped from
the factory a jumper is installed to maintain closed circuit in the
absence of a remote switch.
PRESSURE (PRESS)
This light is on when Spa/Pool Selector switch is on, indicates
the circulation pump is running properly. If pressure light fails
to light, the pump may have lost its prime or water flow may be
restricted by an inadvertently closed valve or clogged filter or
pump basket. If you have determined that there is no water
flow restriction to the heater, you should call a qualified
serviceman.
POWER (THERMOSTAT SELECT) SWITCH
The Pool/Off/Spa switch allows the heater to be turned off
when heating is not desired.
1. “Pool” position - Maintains selected pool temperature.
2. “Off” position - Heater will not come on regardless
of drop in pool or spa temperature.
3. “Spa” position - This allows separate control of spa
water temperature.
