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P/N 472089

Rev. B  4-5-02

14

Installation (Gas Line)

GAS CONNECTIONS

GAS LINE INSTALLATIONS

Before installing the gas line, be sure to check
which gas the heater has been designed to burn.
This is important because different types of gas
require different gas pipe sizes. The rating plate on
the heater will indicate which gas the heater is
designed to burn. Table 1, shows which size pipe is
required for the distance from the gas meter to the
heater. The table is for natural gas at a specific
gravity of .65.

When sizing gas lines, calculate three (3) additional
feet of straight pipe for every elbow used.

When installing the gas line, avoid getting dirt,
grease or other foreign material in the pipe as this
may cause damage to the gas valve, which may
result in heater failure.

The gas meter should be checked to make sure that
it will supply enough gas to the heater and any other
appliances that may be used on the same meter.

The gas line from the meter will usually be of a
larger size than the gas valve supplied with the
heater. Therefore a reduction of the connecting gas
pipe will be necessary. Make this reduction as close
to the heater as possible.

The heater and any other gas appliances must be
disconnected from the gas supply piping system
during any pressure testing on that system, (greater
that ½ PSIG).

The heater and its gas connection must be leak
tested before placing the heater in operation. 

Do not

use flame to test the gas line.

 Use soapy water or

another nonflammable method.

A manual main shut-off valve must be installed
externally to the heater.

Pipe Sized For Length Of Run In Equivalent Feet

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REGULATED MANIFOLD PRESSURE TEST

1. Attach the manometer to the heater jacket.
2. Shut off the main gas valve.
3. Remove 1/8 in. NPT plug on the outlet side of the

valve and screw in the fitting from the manometer kit.

4. Connect the manometer hose to the fitting.
5. Turn on the heater.
6. The manometer must read 4 in. WC for natural gas,

while

 operating.

7. For adjustment, remove the Regulator Adjustment

Cap and using a screwdriver turn the screw clock-
wise to increase - counterclockwise to decrease gas
pressure.

Table 1.

Natural

Maximum inlet gas pressure

10 in. WC

Minimum inlet gas pressure

**5 in. WC

Normal manifold pressure

  4 in. WC

*All  Readings are taken with the heater fired.  Any adjustments
or readings made with heater off will give incorrect readings.

** 6 WC for 400 model

OFF

ON

Regulator Adjustment Cap

1/8" NPT Plug
(Manifold Press)

1/8" NPT Plug
(Inlet Press)

Figure 11.

CAUTION

The use of Flexible Connectors (FLEX) is 

NOT

recommended as they cause high gas pressure drops.

MINIMAX NT LOW NOx GAS PRESSURE REQUIREMENTS*

WARNING

Do not install the gas line union inside the heater
cabinet. This will void your warranty.

Summary of Contents for MiniMax NT Low NOx 200

Page 1: ...ation and service must be performed by a licensed qualified installer service agency or the gas supplier MiniMax NT Low NOx Series POOL SPA HEATERS OPERATION INSTALLATION MANUAL WARNING WHAT TO DO IF...

Page 2: ...stallation Water Connections 13 Installation Plumbing 13 Installation Gas Line 14 Pipe Sizing Chart Gas Pressure Requirements 14 Regulated Manifold Pressure Test 14 Venting Indoor Installations 15 18...

Page 3: ...the MiniMax NT Low NOx pool and spa heater The manufacturer s warranty may be void if for any reason the heater is improperly installed and or operated Be sure to follow the instructions set forth in...

Page 4: ...e with an accurate thermometer Spa or hot tub thermostats may err in regulating water temperatures by as much as 4 F 5 Persons with a medical history of heart disease circulatory problems diabetes or...

Page 5: ...G OPERATION NATURAL GAS 1 STOP Read the safety information above 2 Set the thermostat to the lowest setting 3 Turn off electric power to the heater 4 This heater is equipped with an ignition device wh...

Page 6: ...state be sure your contractor bears the appropriate license SPECIFICATIONS 24 05 2 in SOCKET A DIM 8 84 6 64 30 63 LEG LEG 14 50 3 50 4 875 MODEL 200 250 24 63 21 63 A DIM 15 50 300 400 34 13 27 63 7...

Page 7: ...supplied with this heater must be replaced installer must supply No 18 AWG 600V 105 C U L approved AWM low energy stranded copper wire or it s equivalent Thermal fuse wiring must be replaced with 18...

Page 8: ...NITION MOD EXT SWITCH THERMOSTAT CIRCUIT BOARD JUMPER REQUIRED IF NO 2 WIRE REMOTE SWITCH POOL OFF SPA FRONT PANEL THERMOSTAT SELECT SWITCH TFUSE VALVE REMOTE POOL OFF SPA THERMOSTAT SELECT SWITCH PRE...

Page 9: ...ture 3 Spa position This allows separate control of spa water temperature INDICATOR LIGHT DESCRIPTION The MiniMax NT Heater provides nine status indicator lights six can be seen from the front of the...

Page 10: ...CUIT BLOCK CURRENT SWITCH OR DEVICE CLOSED CIRCUIT PASS CURRENT THERM AUX PRESS HEAT POWER SERVICE FRONT PANEL LEDS FRONT PANEL LEDS HEAT PRESS AUX THERM SERVICE POWER OR POOL OFF SPA THERMOSTAT SELEC...

Page 11: ...ERM INCOMING LINE VOLTAGE THERMOSTAT PWR BREAKER CIRCUIT TSTAT RELAY RMT REMOTE THERMOSTAT CIRCUIT BOARD NO MV CLOSE IF IGNITION MODULE SRVE HI TEMP LIMIT SWITCHES HI TEMP TFUSE MV IND TFUSE GND THERM...

Page 12: ...WHT LOW GAS F1 F2 24 VAC WHT POOL JUMPER REQUIRED J6 PROBE TEMP VLV TPROBE J5 J8 24V J4 J7 IGN MODULE J10 J11 IND PRESSURE SW IF ORIGINAL FACTORY WIRING MUST BE REPLACED INSTALLER MUST SUPPLY UL CSA...

Page 13: ...perature sensing bulb from the inlet outlet header Note If needed you may cut the wire ties holding them together 5 Remove the 16 bolts holding the main inlet outlet head and return head in place exch...

Page 14: ...n must be leak tested before placing the heater in operation Do not use flame to test the gas line Use soapy water or another nonflammable method A manual main shut off valve must be installed externa...

Page 15: ...ombustible materials must be maintained in accordance with type of vent pipe employed in the absence of a clearance recommendation by the vent pipe manufacturer the requirements of the Uniform Mechani...

Page 16: ...on combustible floor or on a non combustible base and in an area where leakage from heat exchanger or water connections will not result in damage to the area adjacent to the heater or the structure Wh...

Page 17: ...be contaminated by corrosive chemical fumes which can void the warranty NOTE The openings listed in Table 2 are free open vent area if the vents incorporate restrictive louvers the vent openings must...

Page 18: ...walkways must be at least 3 ft above any outside air intake located within a 10 ft radius must NOT be within 3 ft of an inside corner of the structure must be at least 1 ft above grade must be located...

Page 19: ...drainage Maintain minimum clearances as indicated below Install a minimum of 4 feet below and 4 feet horizontally from any opening to a building see Figure 18 IMPORTANT When locating the heater consid...

Page 20: ...is running and is primed to close water pressure switch and supply power to heater 2 Set thermostat to lowest setting 3 Set the thermostat rocker switch to the center OFF position 4 Open the access do...

Page 21: ...re than a 3 ft elevation difference between the heater heat exchanger and the pool water line if this is the case the water pressure switch must be reset to maintain open switch contacts with no water...

Page 22: ...r is activated for a heat up period followed by energization of the gas valve for the trial for ignition period When flame is detected during the trial for ignition the ignitor is deactivated and the...

Page 23: ...thermostat knob stopper 5 Set time clock to start circulation system no earlier than daybreak The swimming pool loses less heat at this time 6 For pools that are only used on the weekends it is not ne...

Page 24: ...Then test only once every month or so to be sure it is being maintained See your local pool dealer for help in properly balancing the water chemistry 7 2 6 8 7 0 7 4 7 6 7 8 8 0 8 2 8 4 Add Soda Ash...

Page 25: ...ter operating after pump has shut off Shut off gas supply and call serviceperson Heater exchanger scaled Shut off gas supply and call serviceperson Troubleshooting General SERVICE CHECKS IGNITION MODU...

Page 26: ...X NT LOW NOx HEATER Dual Voltage 1 4 3 5 7 8 9 11 28 30 35 36 38 51 50 48 46 44 45 40 39 17 16 15 14 23 13 34 41 26 27 2 6 10 24 25 22 18 31 33 32 37 47 43 42 12 29 19 20 21 MiniMAX NT Low NOx Heater...

Page 27: ...old Assy 1 472004 472003 472002 472001 32 Burner 4 5 6 8 200 250 300 400 33 Face Plate 1 472069 472068 472067 472052 34 Jacket Upper Panel Left 1 35 Jacket Corner 4 36 Jacket Divider 1 471827 471651 4...

Page 28: ...dent negligence alteration abuse misapplication or misuse The above warranty applies only if the heater is installed and operated in complete compliance with the installation and operation manual prov...

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