1 MiniMax NT ® LN Series Pool & Spa Heaters OPERATION & INSTALLATION MANUAL To Consumer Retain For Future Reference U.S. Patent Numbers 6,295,980 5,318,007 - 5,228,618 5,201,307 - 4,595,825 WARNING FOR YOUR SAFETY - READ BEFORE OPERATING • If you do not follow these instructions exactly, a fire or explosion may result, causing property damage, personal injury or loss of life. • Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or death.
Customer Service If you have questions about ordering Pentair Water Pool and Spa replacement parts, and pool products, please use the following contact information. Customer Service (8 A.M. to 5 P.M. Pacific Time) Phone: (800) 831-7133 (press 3 in voice mail) Fax: (800) 284-4151 Technical Support for Pentair Water Pool and Spa, Inc. Sanford, North Carolina (8 A.M. to 5 P.M. Eastern Time) Phone: (919) 566-8000 Fax: (919) 776-0562 Moorpark, California (8 A.M. to 5 P.M.
Table of Contents Section I. Heater Identification Information ........................................................... 4 Section II. Introduction ............................................................................................ 5 Important Notices ...................................................................................................................................................................... 5 Warranty Information ..................................................
Section I. Heater Identification Information 4 Heater Identification Information To identify the heater, see rating plate on the inner front panel of the heater. There are two designators for each heater, one is the Model Number and the other is the Heater Identification Number (HIN). a.
Section II. Introduction 5 Introduction MiniMax NT ® LN Series Pool and Spa Heaters Congratulations on your purchase of a MiniMax NT LN high performance heating system. Proper installation and service of your new heating system and correct chemical maintenance of the water will ensure years enjoyment. The MiniMax NT LN is a compact, lightweight, efficient, induced-draft, gas fired high performance pool and spa heater that can be directly connected to schedule 40 PVC pipe.
Section II. Introduction 6 CODE REQUIREMENTS The installation must conform with local codes or, in the absence of local codes, with the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CSA B149.1, Natural Gas and Propane Installation Codes. The heater, when installed, must be electrically grounded and bonded in accordance with local codes or, in the absence of local codes, in the USA, with the National Electrical Code, ANSI/NFPA 7; in Canada, with Canadian Electric Code, CSA C22.1.
Section III. Installation 7 Installation Instructions SPECIFICATIONS These installation instructions are designed for use by qualified personnel only, trained especially for installation of this type of heating equipment and related components. Some states require installation and repair by licensed personnel. If this applies in your state, be sure your contractor bears the appropriate license. See Figure 1 for Outdoor and Indoor Installations. DIMENSIONS IN INCHES 24.05 Heater Depth 3.
Section III. Installation 8 MANUAL BY-PASS POOL HEATER TO POOL CHECK VALVE PUMP FILTER MANUAL BY-PASS GATE VALVE Model CHECK VALVE Figure 2. Where the flow rate exceeds the maximum 120 GPM, a manual bypass should be installed and adjusted. After adjustments are made, the valve handle should be removed to avoid tampering. See Figure 2. FROM POOL PLUMBING CONNECTIONS The MiniMax NT LN heater has the unique capability of direct schedule 40 PVC plumbing connections.
Section III. Installation 9 WATER CONNECTIONS Reversing Headers — Reversible Inlet/Outlet Connection The MiniMax NT LN Series heater is factory assembled with right side inlet/outlet water connections. The inlet/outlet header can be reversed for left side water connections without removing the heat exchanger. Reversing Water Connections Tools required: Phillips Screw Driver 9/16 in. Socket and Wrench 1/2 in. & 9/16 in.
Section III. Installation 10 Reversible Inlet/Outlet Connection, cont’d. On the MiniMax NT LN Series heater there is insulation installed by the factory on the return head side of the heaters. This insulation is there so that if the heads are reversed in the field, during initial installation of the heater, the high limits will be insulated from the heat radiating from the flue collector. 6. Return head in position before removal. This view shows the insulation installed by the factory.
Section III. Installation 11 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. The tables, shown on page 12, show 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.
Section III. Installation 12 GAS PIPE SIZING Table 2. PIPE SIZING FOR GAS LINE CONNECTIONS MAXIMUM EQUIVALENT PIPE LENGTH (Ft.) Natural Gas at 1000 B.T.U.
Section III. Installation 13 TESTING GAS PRESSURE Inlet Manifold 1. Push the power switch to “OFF”. 2. Turn the gas valve knob to “OFF”. 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 the gas valve knob to “ON”. 6. Turn on the heater and read the Manometer. 7. The Manometer must read per the values of the Gas Pressure Requirement Table, on manifold side of the gas valve, while operating. 8.
Section III. Installation 14 INDOOR VENTING — General Requirements The vent pipe must be the same size or larger. The MiniMax NT LN heaters are capable of a 360-degree discharge rotation and operate with a positive vent static pressure and with a vent gas temperature less than 400° F. The total length of the horizontal run must not exceed the length that is listed below in the tables. NOTE The allowable vent runs for each vent pipe diameter are different and can not be exceeded.
Section III. Installation 15 INDOOR INSTALLATION (USA ONLY) OUTDOOR SHELTER INSTALLATION (CANADA) Chimney or Gas Vent Vent Cap and Riser Furnished by Installer See page 16 for Vent Adaptors All products of combustion and vent gases must be completely removed to the outside atmosphere through a vent pipe which is connected to the stack adaptor.
Section III. Installation 16 COMBUSTION AIR SUPPLY Air Supply Requirements Guide for MiniMax NT LN Heaters For indoor installation, the heater location must provide sufficient air supply for proper combustion and ventilation of the surrounding area.
Rev. E 4-19-05 Roof Jack Roof Thimble 3 ft. min. Chimney/Gas Vent 2 ft. min. Vent Cap may use a single wall vent pipe with permanently sealed seams, joints and proper insulating materials. must be suitable for use with category III appliances with flue gas temperature ratings less than 400 deg. F. must be the same diameter as the vent connector. Vent pipe extension: must terminate with an approved (listed) roof jack, storm collar, and vent/weather cap.
Section III. Installation 18 OUTDOOR INSTALLATION (Outdoor Shelter Installation in Canada, see page 15) For outdoor installation with an exhaust grill, the heater must be placed in a suitable area on a level, noncombustible surface. Do not install the heater under an overhang with clearances less than 3 feet from the top of the heater. The area under an overhang must be open on three sides.
Section III. Installation 19 ELECTRICAL CONNECTIONS Electrical Rating 60 Hz 120 / 240 Volts AC, single phase CAUTION This heater is designed to operate at 120 or 240 VAC. It is not recommended to be connected to OR operate on a 208 VAC. NOTE • The MiniMax NT LN heater is prewired for 240-volt AC connection using the “RED” connector and the “BEIGE” common connector; see below, Figure 16. For 120-volt AC supply, remove the “BEIGE” common connector and plug it into the “BLUE” common connector.
BLOWER AIR PRESSURE SW.
Section IV. Operation 21 Operation Instruction BASIC SYSTEM OPERATION 1. Start pump, make sure the pump is running and is primed, to close the water pressure switch and supply power to heater. Be sure the pool and/or spa is properly filled with water. Follow the Lighting/Operating instructions below.
Section IV. Operation 22 SAFETY CONTROLS Figure 20. VACUUM AIR PRESSURE (FAN) SWITCH The air pressure switch, (see Figure 20), is a safety device used to insure that the combustion air blower (fan) is operating and has been designed to monitor the vacuum (negative) pressure within the blower housing. The air pressures switch is factory set and is connected upstream of the ignition module. The ignition module does not operate unless the air pressure switch and all safety switches are closed.
Section IV. Operation SAFETY CONTROLS, (cont’d.) 23 Flame Current Check Point HIGH LIMITS A “High Limit”, is a safety device that opens the electrical circuit and shuts off the heater based on a water temperature set point within the “High Limit Device”. The MiniMax NT LN series of heaters contains two (2) high limit devices which are located on the main inlet / outlet header, one sensing the inlet water temperature and one sensing the outlet water temperature.
Section IV. Operation 24 DIGITAL DISPLAY TEMPERATURE CONTROLLER (DDTC) REMOTE BUTTON POWER REMOTE PRESSURE SW POOL SPA SYSTEM INDICATOR LIGHTS THERMOSTAT POOL BUTTON SPA BUTTON OFF HEATING SERVICE TEMPERATURE SETTING POOL OFF BUTTON SPA TEMP. UP PRESS ANY ARROW ONCE TO CHECK SET TEMPERATURE Figure 26. SPA AND POOL TEMPERATURE SET BUTTONS TEMP.
Section IV. Operation 25 Figure 27. Rev.
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.
Section IV. Operation 27 • HEATING The heating light is on any time the thermostat has signaled a call for heat which initializes the ignition safety circuit — the light comes on indicating successful firing of the main burners and stays on until the pool/spa reach the water temperature setting. • SERVICE The service light is off during normal operation of heater. The light only comes on if a problem with a control has occurred or when the heater is first firing.
Section V. Troubleshooting 28 Troubleshooting Instruction TROUBLESHOOTING (DDTC) The DDTC temperature display contains three LED’s with a decimal point between the first and second, this display is also used to display an error code if for some reason there is a failure within the heater control system or a DDTC internal fault. The DDTC will display the actual temperature or set-point temperature or OFF, as selected by the user.
Section V. Troubleshooting 29 TROUBLESHOOTING (GENERAL) Possible Cause Heater will not come on Remedy Check if electrical connections are Automatic ignition system fails correct and securely fastened – If YES, call serviceperson.
Section VI. Maintenance 30 Maintenance Instruction It is recommended that you check the following items at least every six months and at the beginning of every swimming season. 1. Examine the venting system. Make sure there are no obstructions in the flow of combustion and ventilation air. 2. Visually inspect the main burner and the hot surface ignitor. The normal color of the flame is blue. When flame appears yellow, burners should be inspected and cleaned. Check ignitor for damage. 3.
Section VI. Maintenance 31 SPRING AND FALL OPERATION If the pool is being used occasionally, do not turn the heater completely off. Set the thermostat down to 65° F. This will keep the pool and the surrounding ground warm enough to bring the pool up to a comfortable swimming temperature in a shorter period of time. WINTER OPERATION CAUTION • Operating this heater continuously at water temperatures below 68° F. will cause harmful condensation and will damage the heater and void the warranty.
Section VI. Maintenance 32 CHEMICAL BALANCE RULE: 7.4 to 7.6 is a desirable pH range. It is essential to maintain correct pH, see Table 13. POOL AND SPA WATER If pH becomes too high (over alkaline), it has these effects: Your Pentair Pool Products pool heater was designed specifically for your spa or pool and will give you many years of trouble-free service, provided you keep your water chemistry in proper condition.
REPLACEMENT PARTS — NT LN w/DDTC Rev.
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NOTES Rev.
40 36 SAVE THESE INSTRUCTIONS Pentair Water Pool and Spa, Inc. 1620 Hawkins Ave., Sanford, NC 27330 • (919) 566-8000 10951 W. Los Angeles Ave., Moorpark, CA 93021 • (805) 523-2400 P/N 472089 Rev.
