Pentair MiniMax NT Troubleshooting Manual for Electric Heater Operation

Section IV. Operation 26

SET UP

The MiniMax NT LN Heater comes from the factory preset with a pool temperature setting of 78° F. and a preset spa temperature of 100° F., and in the off mode setting. Once the power is turned on, the DDTC board will do a self diagnostic internal check, during this time the display will first read “888”, then the display will switch to three dashes “- - -“, this process takes approximately ten (10) seconds. The DDTC will then illuminate the “Power” LED and “Off” LED, see Figure 27.

1.Turn on the power to the heater; the switch is on the bottom of the electrical junction box located inter- nally on the right side of the cabinet. The DDTC will now go through the self-diagnostic’s test as stated above.

2.Turn on the circulating system pump and make sure that adequate water is being delivered to the heater, The “PRESSURE SW” LED will now illuminate.

3.If you are using the heater with a remote control system, open the right door of the heater to access the rear portion of the DDTC. Locate the three terminals marked “Pool” (J5), “Spa” (J6) and “Com” (J8). If the remote system is a three-wire remote unit, connect the pool lead to the “pool” terminal J5, connect the spa lead to the “spa” J6 terminal and connect the common wire to the “com” terminal J8. If the remote system is a two-wire remote, the remote system will be used to turn the heater on for a selected body of water, Pool or Spa, select which application you are working with and connect one wire to the common terminal J8 and the other wire to either “Pool J5” or “Spa J6”. Close and latch the door.

LED INDICATORS

There are nine lights that can be seen from the front of the control panel, (five are system indicators and four are mode indicators), which helps you understand the operation of the heater, see Figure 26. If something should go wrong, the lights will aid in troubleshooting the problem. An additional four lights can be seen after opening the control panel. These four lights are diagnostic indicators for the service technician to troubleshoot the system.

On the right front of the DDTC board there are four Buttons and corresponding LED lights, see Figure 26. Using the buttons allows you to select one of the four modes and the lights indicate which operational mode that the heater is in, Off, Spa mode, Pool mode or Remote mode. If the heater is not connected to a remote system then the remote mode will not be used.

The following are descriptions of the five system indicators:

• 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:

1.External power to the heater is disconnected; check service panel circuit breaker or fuses;

2.Transformer has failed.

• PRESSURE SW (WATER PRESSURE SWITCH)

This light is on when Spa/Pool Selector switch is on, indicates the circulating 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 technician.

• THERMOSTAT

This light is on when the thermostat contacts close, signaled by the water temperature falling below the set-point, calling for the heater to fire to maintain the desired water temperature.

P/N 472089 Rev. E 4-19-05