Pentair Purex Triton Minimax 300 User Manual

MiniMax® NT Low NOx Series

POOL & SPA HEATERS

OPERATION & INSTALLATION MANUAL

WARNING

FOR YOUR SAFETY - READ BEFORE OPERATING

Warning:

If you do not follow these instructions exactly, a fire or explosion may
result, causing property damage, personal injury or loss of life.
For additional free copies of this manual; call [phone].

1

1

1

U.S. Patent Numbers
5,318,007 - 5,228,618
5,201,307 - 4,595,825

WARNING

Warning: Improper installation, adjustment, alteration, service or maintenance can

cause property damage, personal injury or death. Installation and service must be
performed by a qualified installer, service agency or the gas supplier.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

For Your
Safety

• Do not touch any electrical switch; do not use any phone in your building.

• Immediately call your gas supplier from a neighbor's phone.
Follow the gas supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

To
Consumer
Retain For

Future

Reference

Do not store or use gasoline or other flammable vapors and

liquids in the vicinity of this or other appliances.

Pentair Pool Products, Inc.

1620 Hawkins Ave., Sanford, NC 27330 • [phone]

10951 W. Los Angeles Ave., Moorpark, CA 93021

Rev. C 11-1-01 P/N 471593

• [phone]

Table of Contents

Introduction ............................................................................................................... 3

Important Notices ...................................................................................................................................................................... 3

Code Requirements ................................................................................................................................................................... 3

Warranty Information ................................................................................................................................................................. 4

Operation .................................................................................................................... 4

Safety Rules .............................................................................................................................................................................. 4

HSI (Hot-Surface Ignition) Lighting/Operation - Natural Gas ..................................................................................................... 5

Installation Instructions—Specifications................................................................. 6

Installation — Electrical ............................................................................................................................................................. 7

Installation — Remotes (2 and 3 Wire) ...................................................................................................................................... 8 - 9

Installation — Wiring Diagram ................................................................................................................................................... 10 - 12

Installation — Water Connections.............................................................................................................................................. 13

Installation — Plumbing ............................................................................................................................................................. 13

Installation — Gas Line ............................................................................................................................................................. 14

2

Pipe Sizing Chart/Gas Pressure Requirements ......................................................................................................................... 14

Regulated Manifold Pressure Test ............................................................................................................................................. 14

Venting — Indoor Installations ................................................................................................................................................... 15 - 18

Venting — Outdoor Installations ................................................................................................................................................ 19

Basic Operation — General Description .................................................................................................................................... 20

Basic Operation — Safety Controls ...........................................................................................................................................21 - 22

Basic Operation — HSI Ignition Module .................................................................................................................................... 22

Thermostat (Programming & Layout) ........................................................................................................................................ 23

Temperature & Time Setting (Programming) ............................................................................................................................. 24 - 25

Maintenance ............................................................................................................................ 26

Maintenance Instructions ........................................................................................................................................................... 26

Pressure Relief Valve ................................................................................................................................................................ 26

Maintenance (Water Treatment) ................................................................................................................................................ 27

Trouble Shooting ....................................................................................................... 28

Normal Operation Sequence ..................................................................................................................................................... 28 - 29

Troubleshooting & Service......................................................................................................................................................... 30 - 31

Troubleshooting (General) ......................................................................................................................................................... 32

MiniMax NT Low NOx Parts List & Exploded View (Single Voltage)......................................... 33-34

MiniMax NT Low NOx Parts List & Exploded View (Dual Voltage)............................................ 35-36

Warranty Information ................................................................................................. Back Cover

P/N 471593 Rev. C 11-1-01

3

Introduction

MiniMax NT Low NOx

Pool and Spa Heaters

Congratulations on your purchase of a MiniMax NT Low NOx high performance heating system. Proper
installation and service of your new heating system and correct chemical maintenance of the water will
ensure years of enjoyment. The MiniMax NT Low NOx 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. The
MiniMax NT Low NOx, also comes equipped with the Pentair multifunction temperature controller 7800
which shows, at a glance, the proper functioning of the heater. All HSI (hot-surface ignition) MiniMax NT
Low NOx heaters are designed with a direct ignition device (HSI) which eliminates the need for a standing
pilot. The MiniMax NT Low NOx requires an external power source (120/240 VAC 50/60 Hz) to operate.

IMPORTANT NOTICES

...For the installer and operator of 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 this manual. If you need any more information, or if you have any questions
regarding to this pool heater, please contact Pentair Pool Products, Inc. at [phone].

These heaters are designed for the heating of swimming pools and spas, and should never be employed for
use as space heating boilers, general purpose water heaters, in non-stationary installations, or for the heating
of salt water.

Do not use the heater to protect pools or spas from freezing if the final maintenance temperature desired is
below 60° F. as this will cause condensation related problems.

CODE REQUIREMENTS

The installation must conform with local codes or in the absence of local codes with the latest National Fuel
Gas Code, ANSI Z223.1, and the latest edition of the National Electrical Code, NFPA 70.

Installation in Canada to be made in accordance with the latest CAN/CGA-B149.1 or .2 and CSA C22.1
Canadian Electric Code, part 1.

Rev. C 11-1-01 P/N 471593

Operation

4

This instruction manual provides operating
instructions, installation and service information
for the MiniMax NT Low NOx high performance
heater. The information in this manual applies to
the MiniMax NT Low NOx 200, 250, 300, and
400 natural gas models.

It is very important that the owner/installer read
and understand the section covering installation
instructions, and recognize the local and state codes
before installing the MiniMax NT Low NOx.
History and experience has shown that most heater
damage is caused by improper installation practices.

Operation

WARRANTY INFORMATION

The MiniMax NT Low NOx pool heater is sold
with a limited factory warranty. Specific details are

described on the back cover of this manual and a
copy of the warranty and warranty registration
card are included with the product. Return the

warranty registration card after filling in the serial
number from the rating plate inside the heater.

Pentair Pool Products’ high standards of excellence
include a policy of continuous product improvement
resulting in your state-of-the-art heater. We reserve
the right to make improvements which change the
specifications of the heater without incurring an
obligation to update the current heater equipment.

SAFETY RULES

1. Spa or hot tub water temperatures should never
exceed 104° F. A temperature of 100° F. is
considered safe for a healthy adult. Special
caution is suggested for young children.

2. Drinking of alcoholic beverages before or during
spa or hot tub use can cause drowsiness which
could lead to unconsciousness and subsequently
result in drowning.

3. Pregnant women beware! Soaking in water
above 100° F. can cause fetal damage during the
first three months of pregnancy (resulting in the
birth of a brain-damaged or deformed child).
Pregnant women should stick to the 100° F.
maximum rule.

WARNING

4. Before entering the spa or hot tub, the user
should check the water temperature 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 blood pressure
problems should obtain their physician's advice
before using spas or hot tubs.

6. Persons taking medication which induce
drowsiness, such as tranquilizers, antihistamines
or anticoagulants should not use spas or hot
tubs.

Should overheating occur or the gas supply fail to shut off, turn off the manual gas control valve to the
appliance. Do not use this heater if any part has been under water. Immediately call a qualified service
technician to inspect the heater and to replace any part of control system and gas control which has been
under water.

P/N 471593 Rev. C 11-1-01

Operation (Lighting)

5

MINIMAX NT LOW NOx HSI ELECTRONIC IGNITION LIGHTING/OPERATION -

FOR YOUR SAFETY: READ BEFORE LIGHTING

WARNING

If you do not follow these instructions exactly, a fire or explosion may result causing personal injury, loss of life
and property damage.

Do not attempt to light the heater if you suspect a natural gas leak. Lighting the heater can result in a fire or
explosion which can cause personal injury, death, and property damage.

A. This heater is equipped with an ignition device

which automatically lights the main burners.
Do not try to light the burners by hand.

B. BEFORE OPERATING, smell all around

the heater area for gas. Be sure to smell next
to the floor because some gas is heavier than
air and will settle on the floor.

WHAT TO DO IF YOU SMELL GAS

- Do not try to light any heater.

- Do not touch any electrical switch; do not use
any phone in your building.

- Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's
instructions.

- If you cannot reach your gas supplier, call the
Fire Department.

C. Use only your hand to push in or turn the gas

control knob. Never use tools. If the knob will
not push in or turn by hand, don't try to repair it.
Call a qualified service technician. Forced or
attempted repair may result in a fire or explosion.

D. Do not use this heater if any part has been under

water. Immediately call a qualified service
technician to inspect the heater and to replace
any part of the control system and any gas
control which has been under water.

E. The MiniMax NT Low NOx incorporates the

Pentair temperature controller 7800 to aid you
in the operation of the heater, and to assist in
diagnosing a failure in the heater’s function.

NATURAL GAS

OPERATING INSTRUCTIONS

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

which automatically lights main burners. Do
not try to light the burners by hand.

5. Remove the control access door.

6. Push in gas control knob slightly and turn clock-

wise to “OFF”. (If not on “OFF” position.)

7. Wait five (5) minutes to clear out any gas. If you

then smell gas, STOP! Follow "B" in the safety
information above. If you don't smell gas, go to the
next step.

8. Turn knob on gas control counterclockwise

to “ON”; see Figure 1.

TO TURN OFF GAS TO APPLIANCE

1. Set the thermostat to lowest setting.

2. Turn off all electric power to the heater if
service is to be performed.

3. Remove control access door.

9. Replace the control access door.

10. Turn on the electrical power to the heater.

11. Set the thermostat to the desired setting.

12. If the heater will not operate, follow the instruc­tions "To Turn Off Gas To Heater" and call your
service technician or gas supplier.

Gas

Inlet

Figure 1.

Gas control knob shown in “ON” position.

ON

OFF

4. Push in gas control knob slightly and turn
clockwise to "OFF". Do not force.

5. Replace control access door.

Rev. C 11-1-01 P/N 471593

Installation Instructions

SPECIFICATIONS

IMPORTANT NOTICE: 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.

OUTDOOR VENTILATION

15.50

7.35
2 in. SOCKET

24.05

30.63

6

Figure 2.

LEG

4 in. Kit

P/N 460506

5 in. Kit

P/N 460507

3.50

14.50

6.64

8.84

"A" DIM.

4.875

INDOOR VENTILATION

15.50

7.35

Ø4.88
Ø5.88

3.50

24.05

MODEL

200
250 24.63
300
400 34.13

"A" DIM.

21.63

27.63

INDOOR VENT ADAPTOR

P/N 460506

P/N 460507

4 in. Kit

5 in. Kit

LEG

2.00

30.63

LEG

Figure 3.

LEG

6.64
"A" DIM.

8.84

14.50

4.875

MODEL

"A" DIM.
200
250 24.63
300
400 34.13

21.63

27.63

P/N 471593 Rev. C 11-1-01

Installation (Electrical)

7

ELECTRICAL, ALL HSI UNITS

Electrical Rating 50/60 Hz 120 V.A.C. ONLY

NOTE

The transformer is pre-wired at the factory for 120 VAC operation ,connect line
supply to the line terminal block inside junction box. Use caution in con­necting supply to proper Line (L), Neutral (N), and Ground (GND) terminals;
see below, Figure 5.

NOTE

If any of the original wiring supplied with this heater must be replaced, installer must supply

(No. 18 AWG 105° C. U.L. approved AWM low energy stranded) copper wire or it’s equivalent.

In Canada: wires must be CSA approved.

WARNING

The heater must be electrically grounded and bonded in accordance with local codes or, in the absence
of local codes, with the latest national electrical codes ANSI/NFPA No. 70.

In Canada: CSA standard C22.1 Canada Electrical Code Part 1 and/or local codes.

Always use crimp type connectors when connecting two wires.

LINE TERMINAL BLOCK

GROUND
CONNECTION

NEUTRAL / WHITE 120 VAC

GREEN WIRE

WHITE WIRE

N

POSITIVE LINE FOR 120 VOLTS AC

L

BLACK WIRE

INTERNAL
FA CT OR Y WIRES

Figure 5.

Rev. C 11-1-01 P/N 471593

Installation (Remotes)

TWO-WIRE OR THREE-WIRE REMOTE HOOK-UP

Before connecting the remote control system please read the following:

1. First turn the gas valve to the "OFF" position and power up the
heater, now using the front buttons on the temperature controller,
set the "SPA" and "POOL" temperature to the maximum setting,
see Page 24.

2. Now turn the heater to the "OFF" mode by using the "OFF" button
on the temperature controller, see Page 24 or by using the main
power switch located on the bottom of the junction box.

3. With the heater in the "OFF" mode, locate the three tabs on the back
of the temperature controller as viewed from the backside,
see Figure 6.

4. • Two-wire remote with temperature control:

a) Using 3/16" female quick disconnect connectors, connect one

wire to the "GND" tab of the temperature controller, then the
second wire to either the "SPA" or "POOL" tab.

Figure 6.

8

123

POOL

SPA

GND

b) Now return power to the heater but leaving the temperature controller in the "OFF" position,

see Page 24. (Note: If you used the main power switch to turn off the heater, now turn the main power
switch on.) At this time the remote system has control over the heater, and will turn it on and off when
called for by the remote system thermostat thus keep the pool and spa at the desired temperature.

2 WIRE REMOTE

5 A FUSE
FOR AUX2 (PILOT DUTY ONLY)

AUX2

J2

246

REMOTE

(AUX1)

1

2

POOL

SPA

SPA

PUMP/AUX2

BLOWER

3

GND

GND

10 A

25O V

RELAY

10 A

25O V

RELAY

4

A.C LOAD (PUMP/AUX2)
(PILOT DUTY ONLY)

3

BLOWER (POWER) LINE
BLOWER (POWER) LINE

}

NOT USED

TEMPERATURE
DISPLAY MODE

5 A

25O V

RELAY

2

1

3

C

F

3

1234 123 123456 12

2
1

MV

C
A

24 V

PV/MV

PV

MV

PV/MV

V
P

E
S

T FU

H LIMIT

PRESS

PUMP

PURGE

MODE

135

531

J1

642

TPROBE

POWERLIMITSG VALVEIGN MODULE

12

24 VAC

AIR PRESS

REMOTE SWITCH CONTROLLER

Figure 7.

Three-Wire continued on next page.

P/N 471593 Rev. C 11-1-01

Installation (Remotes)

TWO-WIRE OR THREE-WIRE REMOTE HOOK-UP, (cont’d.)

• Three-wire remote:

a) Using 3/16" female quick disconnect connectors, connect the common wire to the "GND" tab of the

temperature controller, then connect the two remaining wires to the temperature controller
corresponding to the remote control device, pool wire to "POOL" tab, spa wire to "SPA" tab.

b) Now return power to the heater. (Note: If you used the main power switch to turn off the heater, now

turn the main power switch on.) At this time, the remote system has control over the heater and if pool
or spa temperature is below the temperature controller setting, then the heater will try to come on.

c) If you desire to reset the temperature settings of the temperature controller, the remote has to be in the

desired mode for you to change the particular setting. Example: You wish to raise or lower the pool
temperature from the factory setting, you must have the remote system in the pool mode, if you wish to
change the spa temperature, you must have the remote system in the spa mode.

5. Now turn on the gas valve to "OPEN" position, the heater is now ready to
operate.

NOTE

The heater factory settings are 78° F. for the pool and 104° F. for the spa.
When connecting a remote control to the MiniMax, you must install the low
voltage thermostat wires in separate conduit from ANY line voltage wires.
Failure to follow these instructions will cause the thermostat relay to react
erratically. A Remote hook-up deactivates the selector keys on the front

thermostat display panel and gives selection control to the remote.

3 WIRE REMOTE

This icon is not a fault icon
but instead indicates a remote
switching device is connected
to the Pentair Temperature
Controller 7800, and has
overriding selection control
of Pentair Temperature
Controller 7800.

9

5 A FUSE
FOR AUX2 (PILOT DUTY ONLY)

531

246

REMOTE

(AUX1)

1

POOL

POOL

J2

2

SPA

SPA

PUMP/AUX2

BLOWER

3

GND

GND

AUX2

10 A

25O V

RELAY

10 A

25O V

RELAY

4

A.C LOAD (PUMP/AUX2)
(PILOT DUTY ONLY)

3

BLOWER (POWER) LINE
BLOWER (POWER) LINE

Figure 8.

}

NOT USED

TEMPERATURE
DISPLAY MODE

25O V

RELAY

2

1

3

C

F

3
2
1

REMOTE POOL/OFF/SPA

THERMOSTAT SELECT SWITCH

POOL

SPA

COMMON

5 A

1234 123 123456 12

MV

C
A

24 V

PV/MV

PV

MV

PV/MV

E

V

S

P

T FU

H LIMIT

PRESS

PUMP

PURGE

MODE

135

J1

642

POWERLIMITSG VALVEIGN MODULE

TPROBE

12

24 VAC

AIR PRESS

Rev. C 11-1-01 P/N 471593

Installation (Single Voltage Wiring)

MiniMax NT Low NOx 400 HSI Electronic Ignition Wiring Diagram

(SINGLE VOLTAGE)

(ONLY)

BLOCK

BLOCK

GRN

1

1

SUPPLY 120 VAC

HOT

NEU

3

2

2

3

GAS VALVE

4

(HOT)

BLK

GRN

DUAL

FAN

SPEED

LOW SPEED

(NEU)

WHT

5

(HOT)

WHT

HI SPEED

BLK

IGNITOR

HOT SURFACE

HOT SURFACE

IGNITOR

BLK

BURNER

COM

WHT

ORG

WHT

BLK

IGN MODULE

GRN

VAL

TH

S2

L2

L1

S1

N

A

TERM

B

TERM

10

F2

RED

THERMAL FUSE

F1

WHT

WHT

RED

MiniMax NT 400 LOW NOx WIRING DIAGRAM

IF ORIGINAL FACTORY WIRING MUST BE REPLACED, INSTALLER MUST SUPPLY

UL OR CSA (IF CANADA) APPROVED WIRE, 18 GAUGE, 600V, 105 C TEMPERATURE RATING.

THERMAL FUSE WIRING MUST BE REPLACED WITH UL OR CSA (IF CANADA) APPROVED

WIRE, 18 GAUGE, 600V, 125 C TEMPERATURE RATING.

INTERCONNECTING WIRING TO APPLIANCE MUST CONFORM TO THE NATIONAL ELECTRICAL

CODE OR SUPERCEDING LOCAL (WIRING) CODES.

EXHAUST HIGH LIMIT

SHEET METAL

CHASSIS

TERMINATE SUPPLY SAFETY GROUND WIRE (GREEN) HERE

GROUND SCREW WITH PAINT CUTTING WASHER

RED

THERMAL SWITCHES

HIGH LIMIT

THERMAL SWITCHES

RED

WHT

BLU

WHT

W1

WHT

W2

24VAC

FCFLFHPCPL

WHT

RED

RET

FAN CON. BOARD

PH

ORG

BLK

ORG

ORG

ORG

WHT

GRN

SWITCH

WATER PRESSURE

WHT

RED

PROBE

TEMPERATURE

BLU

BLK

ORG

1
2

3
4

1
2
3

1
2
3
4
5
6

1
2

ORG

BLK

2

1

P11P10P7P4

4 32112312345612

LIMITS G VALVE IGN MODULEPOWERTPROBE

AIR PR SW.

REMOTE

BLOWER

3

FC

POOL
SPA
COM

ORG

BLU

WHT

RED

ORG

123

5A

250V

RELAY

10A

250V

RELAY

1

2

AUX2

RELAY

250V

10A

BOND LUG

EXTERNAL

HOT

TERM

FROM

B

BLOCK

120 VAC

(ONLY)

NEU

TERM

FROM

B

BLOCK

ORG

SWITCH

LOW AIR PRES.

ORG

SWITCH

HI AIR PRES.

ORG

SWITCH

LOW GAS PRES.

WHT

ORG

P/N 471593 Rev. C 11-1-01

Installation (Single Voltage Wiring)

MiniMax NT Low NOx 250 HSI Electronic Ignition Wiring Diagram

(SINGLE VOLTAGE)

(ONLY)

SUPPLY 120 VAC

GRN

1

1

WHT

WHT

NEU

2

2

HOT

(HOT)

3

BLK

BLK

BLK

(NEU)

3

4

5

WHTBLK

WHT

FAN

A

TERM

B

TERM

BLOCK

BLOCK

11

BLK

IGNITOR

HOT SURFACE

GRN

GAS VALVE

WHT

(HOT)

N

F2

BLU

RED

WHT

THERMAL FUSE

F1

RED

GRN

WHT

PROBE

TEMPERATURE

WHT

WHT

MiniMax NT 250 LOW NOx WIRING DIAGRAM

IF ORIGINAL FACTORY WIRING MUST BE REPLACED, INSTALLER MUST SUPPLY

UL OR CSA (IF CANADA) APPROVED WIRE, 18 GAUGE, 600V, 105 C TEMPERATURE RATING.

THERMAL FUSE WIRING MUST BE REPLACED WITH UL OR CSA (IF CANADA) APPROVED

WIRE, 18 GAUGE, 600V, 125 C TEMPERATURE RATING.

INTERCONNECTING WIRING TO APPLIANCE MUST CONFORM TO THE NATIONAL ELECTRICAL

CODE OR SUPERCEDING LOCAL (WIRING) CODES.

RED

RED

WHT

THERMAL SWITCHES

EXHAUST HIGH LIMIT

RED

WHT

W2

WATER PRESSURE

ORG

SWITCH

WHT

BLU

ORG

IGN MODULE

BURNER

FC

2

1

3

1
2

3

P11

4
1

2
3

1
2
3
4
5
6

1
2

4 32112312345612

IGN MODULE

PI0

P7

LIMITS G VALVE

P4

POWERTPROBEREMOTE

AIR PR SW.

BLOWER

S2

L2

L1

S1

123

5A

250V

RELAY

POOL
SPA
COM

10A

250V

RELAY

GRN

VAL

TH

BLU

RED

WHT

ORG

AUX2

RELAY

250V

10A

1

2

SWITCH

HI AIR PRES.

ORG

WHT

ORG

SWITCH

LOW GAS PRES.

HIGH LIMIT

SHEET METAL

CHASSIS

TERMINATE SUPPLY SAFETY GROUND WIRE (GREEN) HERE

GROUND SCREW WITH PAINT CUTTING WASHER

BOND LUG

EXTERNAL

THERMAL SWITCHES

RED

W1

HOT

FROM

B

TERM

BLOCK

120 VAC

(ONLY)

NEU

FROM

B

TERM

BLOCK

BLK

BLK

ORG

Rev. C 11-1-01 P/N 471593

Installation (Dual Voltage Wiring)

MiniMax NT Low NOx (ALL MODELS) HSI Electronic Ignition Wiring Diagram

(DUAL VOLTAGE)

OR

240 VAC

120 VAC

BLK

WHT

GRN

A

3

2

1

BLOCK

TERM

BLK

WHT

GRN

WHT

FOR 120 VAC

B

BLOCK

TERM

(BLU)

CON-2F

BLK

1

2

345

BLK

WHT

BLK

(BRN)

CON-2F

BLK

WHT

WHT

FOR 240 VAC

PUR

ORG

BLK

YEL

BLOWER

WHT

12

GRN

(WHT)

CON-2M

GAS VALVE

BLK/WHT

BLK

RED/WHT

RED

MiniMax NT LOW NOx ALL MODELS WIRING DIAGRAM

IF ORIGINAL FACTORY WIRING MUST BE REPLACED, INSTALLER MUST SUPPLY

UL OR CSA (IF CANADA) APPROVED WIRE, 18 GAUGE, 600V, 105˚ C TEMPERATURE RATING.

THERMAL FUSE WIRING MUST BE REPLACED WITH UL OR CSA (IF CANADA) APPROVED

WIRE, 18 GAUGE, 600V, 200˚ C TEMPERATURE RATING.

INTERCONNECTING WIRING TO APPLIANCE MUST CONFORM TO THE NATIONAL ELECTRICAL

CODE OR SUPERCEDING LOCAL (WIRING) CODES.

SHEET METAL

CHASSIS

TERMINATE SUPPLY SAFETY GROUND WIRE (GREEN) HERE

GROUND SCREW WITH PAINT CUTTING WASHER

F2

RED

THERMAL FUSE

F1

WHT

WHT

RED

RED

THERMAL SWITCHES

EXHAUST HIGH LIMIT

RED

HIGH LIMIT

THERMAL SWITCHES

RED

WHT

WHT

BLU

WHT

YEL

WHT

BLK

WHT

ORG

SWITCH

WATER PRESSURE

BLU

WHT

GRN

IGNITOR

HOT SURFACE

BLU

WHT

RED

PROBE

TEMPERATURE

BURNER

WHT

ORG

1

2

3

P11

4

1

2

P10

3

1

2

3

P7

4

5

6

1

2

P4

WHT

WHT

GAS PRESSURE SW.

WHT

ORG

TFUSE GAS IGN

AIR

PRESS SW.

BLOWER

LIMITS VALVE MODULEPOWERTPROBE

REMOTE

S1/120

FC

2

1

3

4 32112312345612

POOL
SPA
COM

RELAY

PUMP RELAY

GRN

12
3

1

10A

250V

2

5A

RELAY

250V

RELAY

LO/FS

ORG

RELAY

250V

10A

AIR PRESSURE SW.

TH

S2L2L1

S1/240

ORG

IGN MODULE

GND

MV1

WHT

BLU

RED

AUX2

BOND LUG

EXTERNAL

P/N 471593 Rev. C 11-1-01

Installation (Plumbing)

PUMP

FILTER

POOL
HEATER

CHECK
VALVE

MANUAL
BY-PASS

TO
POOL

GATE
VALVE

CHECK

VALVE
FROM
POOL

WATER CONNECTIONS

Reversible Inlet/Outlet Connection

The MiniMax NT Low NOx 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.

13

Reversing Water Connections

Tools required:

Figure 9.

1/4 in. Screw Driver
9/16 in. Socket and Wrench

PLUMBING CONNECTIONS

1/2 in. & 9/16 in. Open Wrench

1. Remove the right and left large inspection plates.

2. Disconnect all wires from the high-limit
switches except the short jumper wire.

3. Disconnect the pressure switch wiring.

4. Remove the temperature sensing bulb from the
inlet/outlet header. Note: If needed, you may cut

The MiniMax NT Low NOx heater has the unique
capability of direct schedule 40 PVC plumbing
connections. A set of bulkhead fittings is included with
the MiniMax NT Low NOx to insure conformity with
Pentair’s recommended PVC plumbing procedure.
Other plumbing connections can be used.

the wire ties holding them together.

5. Remove the 16 bolts holding the main inlet/
outlet head and return head in place, exchange
the heads, using the new tube seals supplied
with the heater, re-install the 16 bolts using
moderate torque.

6. Install the temperature sensing probe by passing
the wires through the hole provided on the left
side of the brace panel. Route wires through the

Before operating the heater on a new installation,
turn on the circulation pump and bleed all the air
from the filter using the air relief valve on top of the
filter. Water should flow freely through the heater.

Do not operate the heater unless water in the pool/
spa is at the proper level.

CAUTION

support bracket.

7. Reconnect all the high limit wires and the
pressure switch wiring, routing the wires
through the same hole as the thermostat sensor
wires.

8. Re-install the two large inspection plates on the
appropriate side.

PLUMBING

VALVES

MANUAL BY-PASS

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.

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When any equipment is located below the surface of
the pool or spa, valves should be placed in the
circulation piping system to isolate the equipment

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from the pool or spa.
Check valves are recommended to prevent back

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siphon.

BELOW POOL INSTALLATION

CAUTION

Exercise care when installing chemical feeders so
as to not allow back siphoning of chemical into the
heater, filters or pump.

Rev. C 11-1-01 P/N 471593

If the heater is below water level, the pressure
switch must be adjusted. This adjustment must be
done by a qualified service technician. See Page 22,
Figure 20.

Installation (Gas Line)

14

GAS CONNECTIONS

Pipe Sized For Length Of Run In Equivalent Feet

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.

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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 clock­wise to increase - counterclockwise to decrease gas
pressure.

Regulator Adjustment Cap

1/8" NPT Plug
(Inlet Press)

ON

OFF

1/8" NPT Plug
(Manifold Press)

Figure 10.

CAUTION

The use of Flexible Connectors (FLEX) is NOT
recommended as they cause high gas pressure drops.

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

WARNING

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

P/N 471593 Rev. C 11-1-01

MINIMAX NT LOW NOx GAS PRESSURE REQUIREMENTS*

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

Installation (Indoor)

15

INDOOR VENTING—General Requirements

The vent pipe must be the same size or larger. The MiniMax NT Low NOx 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.

Please note the allowable vent runs for each stack pipe diameter are different and can not be exceeded.

Note that each 90-degree elbow reduces the maximum horizontal vent run by 8 feet and each 45-degree elbow
in the vent run reduces the maximum vent run by 4 feet. See the tables below for the maximum vent lengths
using a 90-degree and 45-degree elbows. The MiniMax NT Low NOx induced-draft pool and spa heater uses
positive pressure to push flue gases through the vent pipe to the outside. This requires a completely sealed vent
system—single wall vent pipe with sealed-seams and joints may be used. Flue gases under positive pressure

may escape into the dwelling with any cracks or loose joints in the vent pipe, or improper vent installation.

The vent pipe must be of a sealed-seam construction such as those listed for use with category III appliances.
Alternately, single wall or double-wall type B duct which has had duct seams and joints permanently sealed
using cements or other suitable means which are rated for use at the flue gas temperatures of 325° F. and are
permanent are acceptable. The use of listed thimbles, roof jacks and/or side vent terminals are required; and the
proper clearances to combustible 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
Mechanical Code should be met. The ventilation air requirements for the MiniMax NT Low NOx heater and
can be found on page 17. It is recommended that vent runs over 18 feet be insulated to reduce condensation
related problems and/or the use of a condensate trap in the vent run close to the heater may be necessary in
certain installations such as cold climates. The MiniMax NT Low NOx is suitable for through-the-wall venting.

Recommended sources for Side-wall vent hood terminals include: The Field Controls Co. (2308 Airport Road,
Kingston, NC 28501, [phone]) and Tjernlund Products Inc. (1601 Ninth Street, White Bear Lake, MN
55110, [phone])—consult manufacturer for model information and availability.

CAUTION

Do NOT combine exhaust vent pipes to a common exhaust vent in multiple unit installations. Run separate vent pipes.

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Installation (Indoor)

INDOOR INSTALLATION (USA ONLY)
OUTDOOR SHELTER INSTALLATION (CANADA)

See page 17 for (Indoor) 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. A
vent pipe extension of the same size must be connected
to the indoor stack adaptor and extended at least 2 feet
higher than highest point of the roof within a 10 foot
horizontal radius, and at least 3 ft. higher than the point
at which it passes through the roof, or as permitted by
local code; see Figures 11 and 12. The vent should
terminate with an approved vent cap (weather cap) for
protection against rain or blockage by snow. Double­wall vent pipe and an approved roof jack shall be
employed through the roof penetration.

The heater must be located as close as practical to a
chimney or gas vent.

Ridge

10 ft.

2 ft. min.

Chimney

3 ft. min.

VENT CAP AND
RISER FURNISHED
BY INSTALLER

Vent
Cap

Roof
Jack

AIR SUPPLY
VENTILATION

16

Figure 11.

CAUTION

The heater should be installed at least 5 feet away
from the pool or spa.

The heater must be placed in a suitable room on a non­combustible 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. When such
locations cannot be avoided, it is recommended that a
suitable drain pan with adequate drainage, be installed
under the heater. The pan must not restrict air flow.

Installations in basements, garages, or underground
structures where flammable liquids may be stored must
have the heater elevated 18 inches from the floor using
a non-combustible base. The following minimum
clearances from combustible materials must be

provided.

Side Front Back Top

Water Connection 18 in. 24 in. - -

AIR SUPPLY
GAS COMBUSTION

OPTIONAL SIDE WALL VENT NT

Figure 12.

The heater should not be installed closer than 6 inches to
any fences, walls or shrubs at any side or back, nor
closer than 18 inches at the plumbing side. A minimum
clearance of 24 inches must be maintained at the front of
the heater.

6"

DOOR

6"

24"

Remaining 6 in. - 6 in. -

Ceiling Clearance - - - 18 in.*

*To ceiling or roof.

Figure 13.

P/N 471593 Rev. C 11-1-01

18"

Installation (Indoor)

BASE FOR USE ON COMBUSTIBLE FLOORS

24 GA. (MIN.) GALVANIZED SHEET METAL.

FOR AIR CIRCULATION). COVER BLOCKS WITH

(LAID WITH ENDS UNSEALED AND JOINTS MATCHED

HOLLOW MASONARY BLOCKS, NOT LESS THAN 4" THICK

SHEET METAL

BLOCKS

6" Min.

6" Min.

17

NOTE

The heater requires two uninterrupted air supply
openings; one for ventilation and one to supply

oxygen for proper gas combustion. The air supply
openings should be sized according to Table 2.

Air supply requirements below apply to all

MiniMax NT Low NOx heaters*.

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Table 2.

*NOTE

The openings listed in Table 2 are free open vent
area—if the vents incorporate restrictive louvers,
the vent openings must be increased to
compensate for the area blocked by the louvers (or
grills).

I

NSTALLATION ON FLOORS CONSTRUCTED

OF COMBUSTIBLE MATERIALS

The heater may be placed on a “combustible floor”
using either of the two methods listed below:

b) Construct a non-combustible base from masonry

blocks as illustrated, see Figure 14.

Figure 14.

CAUTION

Chemicals should not be stored near the heater
installation. Combustion air can be contaminated by
corrosive chemical fumes which can void the warranty.

INDOOR VENT ADAPTORS

(FITS ALL MODELS)

The proper draft hood and adapter must be installed on
the heater as shown below and on pages 15 and 16:

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a) Use Listed Factory Non-combustible Base Kit

Rev. C 11-1-01 P/N 471593

for use on combustible floors.

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705064.ni5

Indoor Vent
Adaptor

Figure 15.

Installation (Indoor)

1' min.

F

Vent Hood

1' min.

F

18

C

1' min.

above grade

B

3'

Recommended sources for

side wall Vent Hood; see page 15,

Section Venting.

Vent Hood

Figure 16.

D

4'

H

INDOOR INSTALLATIONS

MINIMAX NT LOW NOx VENTING GUIDELINES

Vent

Cap

10 ft.

J

3 ft. min.

G

Air Supply

Combustion

Air Supply

Ventilation

4'

E

Vent Hood

L

K

Chimney

A

G

7'

4 ft. below

4 ft. horizontally

1 ft. above

must be not less than 7 ft. above public 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.
C

must be located the following distances away from any door, window, or gravity air inlet:

D

E

Walkway

Vent termination for side wall installations:

B

A

Air Supply

See Air Supply Requirements Table.

F

(Table 2 on page 17.)

G

2 ft. min.

vent terminated at

least 24" above

any object within 10 ft.

Vent pipe extension:

Detail H

Ridge

P/N 471593 Rev. C 11-1-01

must extend at least 3 ft. higher than the

point at which it passes through the roof,

or as permitted by local code.

must use a double-wall vent pipe through

the roof penetration.

must terminate with an approved (listed)

roof jack, storm collar, and vent/weather cap.

J

K

L

Vent for roof penetration installations:

must be the same diameter as the

vent connector.

must be suitable for use with category III

appliances which have flue gas temperatures

of less than 400 deg. F.

may use a single wall vent pipe with

permanently sealed seams and joints.

Installation (Outdoor)

19

VENTILATION

OUTDOOR INSTALLATION ONLY (Outdoor Shelter Installation in Canada, see page 16)

For outdoor installation with built in vent, 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.

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 17.

IMPORTANT!

When locating the heater, consider that high winds can roll over or deflect off adjacent buildings
and walls. Normally, placing the heater at least three feet from any wall will minimize downdraft.

NOTE

This unit shall not be operated outdoors at temperatures below -20o F. for natural gas.

OUTDOOR INSTALLATION

MINIMAX NT VENTING GUIDELINES

D

Walkway

1'

4'

C

Figure 17.

A

4'

3'

B

4'

Property Line

E

Check local building codes

E

for setback requirements.

Vent T ermination:

Must be not less than 7 ft. above public walkways.
Must be at least 3 ft. above any forced

A

air inlet located within a 10 ft. radius.

Must be located the following distances away
from any door, window, or gravity air inlet:

4 ft. below, or

B

4 ft. horizontally, or

C

1 ft. above

D

Rev. C 11-1-01 P/N 471593

Basic Operation

20

GENERAL DESCRIPTION

The MiniMax NT Low NOx Pool and Spa Heater is a fan-assisted induced draft appliance. The MiniMax
NT Low NOx is available in 200,000, 250,000, 300,000 and 400,000 btu/hr. capacities and are certified for
both indoor and outdoor installations. The MiniMax NT Low NOx version natural gas pool heater must be
used for installations in the South Coast Air Quality Management District (SCAQMD)—these heaters are
certified to comply with SCAQMD Rule 1146.2 and also meet Ventura Co. APCD Rule 74.11.1.

The MiniMax NT Low NOx is designed to operate both in stackless outdoor installations and in indoor
stack vent installations—the indoor installation may be made using Kit 460506 or 460507; see pages 6 and
17, vertical vent pipe or with a horizontal vent pipe and a Listed side-wall vent.

BASIC SYSTEM OPERATION

TO OPERATE HEATER

1. Start pump, make sure the pump is running and is primed, to close water pressure switch and

supply power to heater.

2. Set thermostat to lowest setting by using up/down arrow keys. See page 24.

3. Push the off key on the Pentair temperature controller 7800 (the amber “off “ led will illuminate).
See page 24.

4. Open the access doors.

5. Push in the gas control knob slightly and turn the knob clockwise to “OFF”. See page 5 Natural Gas

Instructions.

6. Wait (5) minutes to clear out any gas. If you then smell gas STOP. Follow the safety information
(stated earlier in the lighting instructions section). If you don’t smell gas, go to the next step. See

page 5 Natural Gas Instructions.

7. Turn the knob on the gas control counter clockwise to the “ON” position. See page 5 Natural Gas
Instructions.

8. Replace the doors.

9. Push either the “Pool” or “Spa” key to start the heater. NOTE: “Pool” key is Factory set at 78° and
“Spa” key is set at 104°.

10. Set the thermostat if needed by using the up/down arrows to set the desired temperature.

a. Fan motor starts, which closes draft proving switch.

b. Ignition module is energized after fan prepurge cycle is completed approximately 2 minutes.

c. Check for powering up the (glow coil) hot-surface ignitor by viewing through the sight glass.

11. The ignitor will warm up and then gas valve opens to ignite the main burners.

12. Heater will operate until desired temperature is reached.

P/N 471593 Rev. C 11-1-01

Basic Operation

SAFETY CONTROLS

AIR PRESSURE (FAN) SWITCH

The air pressure switch is a safety device used to insure
that the 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 in the ignition module circuit—
the ignition module does not operate unless the air
pressure switch and all safety switches are closed.

NOTE

Some models of MiniMax NT Low NOx heaters,
manufactured before 10-15-01, used both a HIGH
and LOW air pressure switch.

WATER PRESSURE SWITCH

Figure 18.

21

AIR PRESSURE SWITCH

The water pressure safety switch closes when there is
a sufficient flow of water to the heat exchanger to
safely operate the heater. The switch operation must
be verified during initial operation of the heater after
installation—the switch is set at 1 PSIG and the switch
contacts must not be closed in the absence of water
flow. NOTE: See, Below Pool Level Installation
instructions on page 13. The switch may remain closed
with no water flow if there is more 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 flow.

NOTE

If the pool is more than one floor above or one floor
below the heater, the pressure switch may have to
be replaced with a flow switch.

LOW GAS PRESSURE SWITCH
(LOW NOx Versions Only)

The MiniMax NT Low NOx heater uses a low gas
supply pressure switch, ahead of the gas valve, to
prevent operation of the heater when the gas supply
pressure is below the minimum required for proper
operation of the burners. The switch is factory set. In
the event that the switch does not close and prevents
the firing of the heater, the cause of the low gas supply
pressure must be corrected. Typical causes are
undersized supply piping, undersized gas meter or low
gas regulator setting (gas supply regulator and gas
meter problems are typically corrected by your local
gas company).

Figure 19.

Adjustment Knob

Typical Water Pressure Switch

Figure 20.

Low Gas Pressure Switch

Rev. C 11-1-01 P/N 471593

Basic Operation

22

SAFETY CONTROLS, (cont’d.)

IGNITION MODULE

The Ignition Module is microprocessor based and operates on 24 VAC supplied by the transformer. The
control utilizes a microprocessor to continually and safely monitor, analyze, and control the proper operation
of the gas burners. The module with the presence of the flame sensor/ignitor or remote sensor, using flame
rectification, allows the heater to operate.

HIGH LIMITS

A “High Limit”, is a safety device that opens the electrical circuit and shuts off the heater based on a
temperature set point within the “High Limit Device”. The MiniMax NT Low NOx series of heaters
contains three (3) high limit devices, two (2) are located on the main inlet / outlet header, one sensing the
inlet water temperature and one sensing the outlet water temperature. The third high limit is located on the
exhaust outlet and senses the temperature of the flue gas.

OPERATION OF IGNITION MODULE

HEAT MODE

• When a call for heat is received from the thermostat supplying 24 VAC to the “W” module terminal, the
control will perform a self check routine, flash the diagnostic LED, on units manufactured prior to
10-15-01, (located on the module) for up to four seconds and begins the safety timing ignition sequence.
After the fan prepurge cycle, the hot surface ignitor 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 gas valve remains
energized. The thermostat and main burner flame are constantly monitored to assure the system
continues to operate properly. When the thermostat is satisfied and the demand for heat ends, the main
valve is de-energized immediately.

FAILURE TO LIGHT-LOCK OUT

Should the main burner fail to light, or flame is not detected during the trial for ignition period, the control
will go into lockout and the gas valve will be turned off immediately. The thermostat controller will display
a flame failure error (icon/service LED) and recovery from lockout requires a manual reset by either
resetting the 7800 Thermostat or removing 24 VAC from the system by turning off main power switch
(located on the junction box behind right door) for a period of 5 seconds.

FLAME FAILURE—RE-IGNITION

If the established flame signal is lost while the burner is operating, the control will respond within 1 second.
The gas valve is de-energized and the control starts a new ignition sequence in an attempt to relight the
burner. If the burner does not relight, the control will go into lockout, requiring a manual reset.

P/N 471593 Rev. C 11-1-01

Thermostat (Programming & Layout)

23

MINIMAX NT LOW NOx PENTAIR TEMPERATURE CONTROLLER 7800

(See Figure 21, for keypad and Pentair Temperature Controller layout details.)

GENERAL

The MiniMax NT Low NOx Pentair Temperature Controller 7800 is the heart of the
control system. It controls all functions of the heater after first verifying that all safety
controls are functioning normally. If a malfunction is detected, the Pentair Temperature
Controller 7800 will flag the error with both the RED “Service” LED lighting and a
corresponding LCD icon appearing on the Pentair Temperature Controller 7800, pin
pointing the affected safety control(s). NOTE: The exception is the AUX (REMOTE)
LCD icon which appears when a REMOTE Control (or Remote Switch) is connected to
the Pentair Temperature Controller 7800, which overrides the “POOL” and “SPA” keypads
on the control, giving “ON” selection control to the REMOTE.

BASIC THERMOSTAT OPERATION

The Pentair Temperature Controller 7800 comes pre-programmed for use with the spa
temperature set at 104° F. and the pool temperature set for 78° F.— and with default
display mode set to display degrees F. (this may be adjusted to display in degrees C. with jumper on back of board), see
Figure 21.

You need not do anything further to enjoy your heater other than set it in the pool or spa mode by depressing the key
located under the corresponding “POOL” or “SPA” LED light. The LED above the selection will light and the
corresponding “POOL” or “SPA” LCD icon on the display will appear.

This icon is not a fault icon
but instead indicates a remote
switching device is connected
to the Pentair Temperature
Controller 7800, and has
overriding selection control
of Pentair Temperature
Controller 7800.

NORMAL OPERATION (NO REMOTE)

Each temperature setting in either POOL or SPA mode is settable independently.
If the Factory’s presetting of 78° F. for “Pool” and 104° F. for “Spa” is not desirable, you may adjust these settings. See

page 24 for changing the Factory Temperature Settings. To set the temperature while in SPA mode press the TEMP UP
key (with UP arrow) to increase or TEMP DOWN (with DOWN arrow) to decrease the set temperature to that desired.
NOTE: The left hand display indicates the current real-time temperature. To set the temperature for POOL mode, first
switch to POOL mode by depressing the “POOL” key and repeat the temperature setting procedure in this example. The
Pentair Temperature Controller 7800 remembers the last set temperature for both the POOL and SPA mode and you may
cycle between the two settings with the POOL and SPA selector keys.

In NORMAL operation, pressing the MODE key allows you the cycle between the right-hand display showing the SET
TEMP for the currently active POOL or SPA or the TIME.

(Pentair Temperature Controller 7800 Layout)

OFF SPAPOOL

DAY ICON

DISPLAY IN TIME MODE ONLY

SET TEMP/TIME

STEP

TFUSEAUXFANPRESSH-LMTIGN

ALTERNATE DISPLAY

SYSTEM
NORMAL

HEAT

TEMP

TEMP

F = FAHRENHEIT
C = CELSIUS
P = P.M.
BLANK = A.M.

POOL OR SPA
(DISPLAY ALTERNATELY
ON LCD TO SHOW ACTIVE SELECTION)

FAULT CONDITION LCD ICONS

SET

MODE

POWER

SERVICE

FLASH IN PROGRAM MODE

ALTERNATE DISPLAY C or F.

F = FAHRENHEIT
C = CELSIUS

CURRENT TEMP

PROGRAM

Figure 21.

KEYPAD SWITCHES

Rev. C 11-1-01 P/N 471593

Temperature & Time Setting (Programming)

TO CHANGE THE FACTORY TEMPERATURE SETTINGS:

1. Before changing the temperature, make sure the “Temperature” is in the right window, see pages 24
and 25, if “Time” is displayed, press the MODE key to change to the “Temperature Mode”.

SET

PROGRAM

MODE

2. To change the Pool Temperature setting, press the POOL key.

OFF SPAPOOL

3. To Raise or Lower the Pool Temperature setting, press the proper TEMP key
until the desired setting is displayed.

STEP

NOTE: During Programming of the Pool Temperature, the two buttons on the
right are used to or the display setting numbers.

Increase

( )

Raise

Decrease

( )

Lower

24

TEMP

TEMP

NOTE: Pool Temperature is now set.

4. You can leave the right window displaying the set “Temperature” or by pressing
the MODE key, you can return to the “Time” Mode.

STEP

NOTE: To re-set the Spa Temperature, follow the above steps 1. through 4.
while in the “Spa Heating” Mode.

TIME SETTING

1. Make sure heater is turned “OFF” and not in the POOL or SPA “ON” Mode.

OFF SPAPOOL

2. Place the Controller in Programming Mode by depressing the SET and MODE buttons at the same time.

SET

PROGRAM

MODE

TEMP

TEMP

NOTE: During Programming of the Time Setting, the two buttons on the right

are used to or the display setting numbers.

P/N 471593 Rev. C 11-1-01

Increase

( )

Raise

Decrease

( )

Lower

STEP

TEMP

TEMP

Time Setting (Programming)

TIME SETTING, (cont’d.)

25

3. The first setting, once you enter the Programming Mode, will be the Day. The
Day icon will be flashing. Use the UP or DOWN arrow TEMP keys to locate
the appropriate day, then press the SET key. The Day is now set and the Hour
Time icon will start to flash.

SET

PROGRAM

MODE

4. With Hour Time icon flashing, use the UP/DOWN arrow TEMP keys. Set the
Hour to the proper time, “P” will show to the right for PM, and blank for AM.

Once the proper Hour is visable, press the SET key. The Minute icon’s will
now start flashing.

SET

PROGRAM

MODE

5. With the Minute icon’s flashing use the UP/DOWN arrow TEMP keys and
select the proper Minute setting, then press the SET key. The Day and Time are
now set and the Day icon will be flashing.

TEMP

STEP

TEMP

TEMP

STEP

TEMP

TEMP

STEP

TEMP

SET

PROGRAM

MODE

6. Press the SET and MODE keys at the same time to return to the Operational Mode.

SET

PROGRAM

MODE

NOTE

During the programming of the CLOCK/DAY function, you touch only the MODE key and a appears
in the upper left corner of the “Current Temperature Display Area”, this represents a delay function and
will be used for future functions and accessories to the MiniMax NT Low NOx. When the appears,
simply stop the programmaing, “do NOT touch any key for 30 seconds”, the controller will
automatically return to the operating mode, now by pressing the “SET & MODE keys” at the same time,
you will re-enter the programming function, and the icon will disappear.

D

D

D

Rev. C 11-1-01 P/N 471593

FOR PRV
INSTALLATION
DRILL THRU
THE NPT PORT

Maintenance

MAINTENANCE INSTRUCTIONS

26

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. Keep the heater area clear and free from
combustibles and flammable liquids.

Figure 22.

LOW-NOx

ENERGY SAVING TIPS

1. If possible, keep pool or spa covered when not in
use. This will not only cut heating costs, but also
keep dirt and debris from settling in the pool and
conserve chemicals.

2. Reduce the pool thermostat setting to 78° F. or
lower. This is accepted as being the most healthy
temperature for swimming by the American Red
Cross.

3. Use an accurate thermometer.

4. When the proper maximum thermostat settings have
been determined, tighten the thermostat knob
stopper.

Pressure Relief Valve

In some installations, a pressure relief valve (PVR) is
required on the
MiniMax NT Low
NOx. To install a
PRV, carefully drill
a 3/8 in. hole in
center of 3/4 in.
NPT port (on main
header) being
careful to drill
only thru wall at
bottom of 3/4 in.

Figure 23.

NPT port and no
deeper—now thread in the 3/4 NPT PRV. NOTE:
(A.S.M.E. version varies from illustration. It is of bronze
construction, and is supplied with the A.S.M.E. Section
IV, pressure relief valve pre-installed at factory.) Test the
relief valve at least once a year by lifting up lever.

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 necessary to leave the thermostat set at 78° F.
Lower the temperature to a range that can be
achieved easily in one day. Generally, this would be
10° F. to 15° F., if pool heater is sized properly.

7. During the winter or while on vacation, turn the
heater off.

8. Set up a regular program of preventative
maintenance for the heater each new swimming
season. Check heat exchanger, controls, burners,
operation, etc.

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

If the pool won't be used for a month or more, turn the
heater off at the main gas valve. For areas where there is
no danger of water freezing, water should circulate
through the heater all year long, even though you are not
heating your swimming pool. The MiniMax NT Low
NOx should not be operated outdoors at temperatures
below 0° F. for propane and -20° F. for natural gas.

P/N 471593 Rev. C 11-1-01

Where freezing is possible, it is necessary to drain the
water from the heater. This may be done by opening the
drain valve, located at the inlet/outlet header (see Figure

23.), allowing all water to drain out of the heater. It
would be a good practice to use compressed air to blow
the water out of the heat exchanger. (See additional

notes under Important Notices in Introduction.)

Maintenance (Water Treatment)

27

CHEMICAL BALANCE

POOL AND SPA WATER

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.

Three major items that can cause problems with your
pool heater are: improper pH, disinfectant residual, and
total alkalinity. These items, if not kept properly
balanced, can shorten the life of the heater and cause
permanent damage.

CAUTION

Heat exchanger damage resulting from chemical
imbalance is not covered by the warranty.

WHAT A DISINFECTANT DOES

Two pool guests you do not want are algae and bacteria.
To get rid of them and make pool water sanitary for
swimming - as well as to improve the water's taste, odor
and clarity - some sort of disinfectant must be used.

Chlorine and bromine are universally approved by health
authorities and are accepted disinfecting agents for
bacteria control.

RULE: 7.4 to 7.6 is a desirable pH range. It is essential
to maintain correct pH, see Table 4.

If pH becomes too high (over alkaline), it
has these effects:

1. Greatly lowers the ability of chlorine to destroy

bacteria and algae.

2. Water becomes cloudy.

3. There is more danger of scale formation on the

plaster or in the heat exchanger.

4. Filter elements may become blocked.

If pH is too low (over acid) the following
conditions may occur:

1. Excessive eye burn or skin irritation.

2. Etching of the plaster.

3. Corrosion of metal fixtures in the filtration and

recirculation system, which may create brown, blue,
green, or sometimes almost black stains on the
plaster.

4. Corrosion of copper in the heater, which may cause

leaks.

5. If you have a sand and gravel filter, the alum used as

a filter aid may dissolve and pass through the filter.

WHAT IS A DISINFECTANT
RESIDUAL?

When you add chlorine or bromine to the pool water, a
portion of the disinfectant will be consumed in the
process of destroying bacteria, algae and other oxidiz­able materials. The disinfectant remaining is called
chlorine residual or bromine residual. You can determine
the disinfectant residual of your pool water with a reliable
test kit, available from your local pool supply store.

You must maintain a disinfectant residual level adequate
enough to assure a continuous kill of bacteria or virus
introduced into pool water by swimmers, through the air,
from dust, rain or other sources.

It is wise to test pool water regularly. Never allow
chlorine residual to drop below 0.6 ppm (parts per
million). The minimum level for effective chlorine or
bromine residual is 1.4 ppm.

pH - The term pH refers to the acid/alkaline balance of
water expressed on a numerical scale from 0 to 14. A test
kit for measuring pH balance of your pool water is
available from your local pool supply store; see Table 3.

Table 3.

Strongly Acid Neutral Strongly Alkaline

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Muriatic Acid has a pH of about 0. Pure water is 7
(neutral). Weak Lye solution have a pH of 13-14.

pH Chart

CAUTION: Do not test for pH when the chlorine
residual is 3.0 ppm or higher, or bromine residual
is 6.0 ppm or higher. See your local pool supply
store for help in properly balancing your water
chemistry.

RULE: Chemicals that are acid lower pH. Chemicals
that are alkaline raise pH.

Table 4.

6.8 7.0

Add Soda, Ash or
Sodium Bicarbonate

pH Control Chart

7.4 7.6

7.2

7.8

8.0 8.2 8.4

Add AcidMarginalIdealMarginal

ALKALINITY High - Low:

"Total alkalinity" is a measurement of the total amount
of alkaline chemicals in the water, and control pH to a
great degree. (It is not the same as pH which refers
merely to the relative alkalinity/acidity balance.) Your
pool water's total alkalinity should be 100 - 140 ppm to
permit easier pH control.

A total alkalinity test is simple to perform with a reliable
test kit. You will need to test about once a week and
make proper adjustments until alkalinity is in the proper
range. 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.

Rev. C 11-1-01 P/N 471593

Troubleshooting—Normal Operation Sequence of Heater

28

NORMAL OPERATION SEQUENCE

(Refer to Figure 21 of Pentair Temperature Controller 7800 keyboard)

The heater features a fully automated firing start-up and shutdown sequence under the control of the
MiniMax NT Low NOx Pentair Temperature Controller 7800.

Now that the heater has been properly installed and wired for either remote operation or local operation, and
you have setup the Pentair Temperature Controller 7800 temperature setpoints as described earlier in manual
in Thermostat section, the following is the normal operating sequence when the heater turns on the and the
thermostat calls for heat for the pool or spa.

1. The fan will start beginning the heater’s safety prepurging cycle which lasts for 2 minutes. If at anytime
during the prepurge cycle the Pentair Temperature Controller 7800 detects that a safety control is not
working due to either a safety control malfunction or other unsafe condition the firing sequence will stop
until the unsafe condition is removed— “the fault icon related to the problem will illuminate”.

2. After proper completion of the prepurge cycle, the hot surface ignitor (glow coil) will turn on (preheat)
for 40 seconds. Once the 40 seconds is passed, the main gas valve will open. At this time, if flame is not
safely established and is dectected by the flame sensing curcuit, the ignition module and Pentair
Temperature Controller 7800 will shut down and will display an ignition fault and luminate the red
service light.
period of non-operation of the heater it is normal for the first ignition attempt to not complete. To clear
the fault condition power to the Pentair Temperature Controller 7800 must be cycled to reset system. If
heater continues to fail to light have heater inspected by a qualified service person before placing heater
back in service.

Please note that on initial firing of heater when gas supply piping is full of air or after long

Insufficient waterflow (pump icon displays), excessive water temperature (high limit icon) cause a
“soft-lockout” of the firing sequence—which means if the cause of the problem clears by itself (or with
human intervention ie., turning on pump, etc.) such as a slow to prime water pump finally pumping
adequate waterflow causing the water pressure (safety) switch to close, the ignition sequence
automatically restarts again.

The other category of fault conditions lead to a “hard lockout” of the firing sequence which require a
qualified service person to correct before the heater is returned to service. In “hard lockout” the heater
must be manually reset (by toggling power to Pentair Temperature Controller 7800) after correction of
the fault condition.

Examples of causes of “hard lockouts” include inadequate gas supply pressure and/or failure of fan or
fan pressure switches, which all appear as air/gas pressure faults illuminating “blower fan” fault icon and
RED “service required” LED.

P/N 471593 Rev. C 11-1-01

Troubleshooting—Normal Operation of Heater

29

3. After normal firing of the heater (main burners) the heater will continue to operate until the
temperature setpoint is reached (thermostat satisfied). As the pool/spa loses heat the heater will refire
and continue to operate cycling automatically to maintain the selected temperature setpoint for either
the pool or spa. If at anytime during the firing of the heater an unsafe condition is detected the

heater will stop firing and an automatic safe shutdown sequence will begin. Investigate and have
corrected the cause of the abnormal firing termination before placing heater back in operation.

Please Note: During the firing of the heater, you decide to change to the pool or spa selection by

depressing the selector key for “POOL” or “SPA”, the heater will first acknowledge the new selection by
flashing the new selection’s corresponding selection LED “POOL” or “SPA”, however, the heater will first
complete a safe shutdown sequence before automatically switching to the new selected setting and safely
initiating a new firing sequence using the the new temperature setpoint. During this automatic crossover
sequence the keyboard on the Pentair Temperature Controller 7800 will not accept any further keying until
the cycle completes—the exception is you may still stop the heater with the “OFF” key.

SYSTEM

NORMAL

HEAT

TEMP

TEMP

POOL OR SPA
(DISPLAY ALTERNATELY
ON LCD TO SHOW ACTIVE SELECTION)

FAULT CONDITION LCD ICONS

POWER

SERVICE

SET

MODE

CURRENT TEMP

PROGRAM

SET TEMP/TIME

TFUSEAUXFANPRESSH-LMTIGN

OFF SPAPOOL

STEP

Figure 24.

Illustration of Pentair Temperature Controller 7800 with all fault icons displayed for clarity.

Rev. C 11-1-01 P/N 471593

Troubleshooting & Service

LEGEND OF FAULT ICONS AND TYPE OF PROBLEMS FLAGGED

30

This fault icon displays whenever there is an unexpected loss of flame.
This condition may arise from air in gas supply line or malfunction of flame
detection circuit or related hardware.This is a hard lockout condition
requiring a manual reset to clear.

This fault icon displays whenever one or more of safety temperature limit
switches open to flag an excessive temperature condition. This is a soft
lockout condition and if the condition clears the fault icon will clear and
normal operation of heater will procede.

This fault icon displays whenever the thermal fuse has opened due to a flame
roll-out or other abnormal condition causing excessive temperatures in the
cabinet. The cause of the fault must be corrected and the one-shot fuse
replaced before icon can be cleared.

This fault icon displays whenever there is a failure of either the low gas
pressure switch (due to low pressure or switch failure) or additionally the fan
and/or air pressure switch circuit has failed resulting in an open safety circuit.
The nature of these faults are mission critical for the safe operation of the
heater and result in a hard lockout. The cause of the fault must be corrected
and the heater will require a manual reset by toggling the power supplied to
the 7800 Controller to clear the fault.

This fault icon displays whenever insufficient waterflow causes the water
pressure switch to fail to close. This is a soft lockout condition and will clear
by itself if the waterflow is restored. The icon will then clear and if the heater
was attempting to fire the cycle will restart and continue.

P/N 471593 Rev. C 11-1-01

Troubleshooting & Service

SERVICE CHECKS—IGNITION MODULE

skcehCecivreS

motpmySeruC/esuaC

daeD.1deriwsiM.A

noitingion—notatsomrehT.2deriwsiM.A

rotingion,noevlaV.3rotingievitcefeD.A

deriwsiM.B

evlavon,norotingI.4nepoliocevlaV.A

31

dabremrofsnarT.B

dabrekaerbtiucriC/esuF.C

)noydaetsrofDELkcehc(lortnocdaB.D

WlanimrettaegatlovontatsomrehtdaB.B

)rotingitaegatlovkcehc(lortnocdaB.C

eriwevlavnepO.B

)2V&1Vneewtebegatlovkcehc(lortnocdaB.C

,IFTgnirudyakoemalF.5

)IFTretfa(esnesemalfon

FLAME SENSOR CURRENT CHECK

MULTI-PURPOSE METER

USE MICROAMP SCALE

RED (+)

rotingidaB.A

eriw1SdaB.B

renrubtadnuorgrooP.C

)tnerrucemalfkcehc(emalfrooP.D

Figure 25.

BLACK (-)

2465H MODULE

SERVICE CHECKS

Flame current is the current which passes through the flame from the sensor to ground. The minimum flame current necessary to
keep the system from lockout is 0.7 microamps. To measure flame current, connect an analog DC microammeter to the FC1/FC2
terminals per figure. Meter should read 0.7 µA or higher. If meter reads below “0” on scale, meter leads are reversed. Disconnect
power and reconnect meter leads for proper polarity.

Rev. C 11-1-01 P/N 471593

Troubleshooting - General

Possible Cause Remedy

Heater will not come on

Automatic ignition system fails Check if electrical connections are

Pump not running Place pump in operation

Pump air locked Check for leaks

Filter dirty Clean filter

Pump strainer clogged Clean strainer

Defective wiring or connection Repair or replace wires

Defective pressure switch Replace switch

32

correct and securely fastened –
If YES, call serviceperson.

Defective gas controls Call serviceperson

On-Off switch in "OFF" position Turn switch to "ON"

Heater Short Cycling (Rapid On and Off Operation)

Insufficient water flow Clean filter and pump strainer

Defective wiring Repair or replace wiring

Defective flow valve or out of adjustment Call serviceperson

Defective hi-limit and/or thermostat Call serviceperson

Heater Makes Knocking Noises,
Make sure all valves on system are open

Heater operating after pump has shut off Shut off gas supply and call serviceperson

Heater exchanger scaled Shut off gas supply and call serviceperson

CAUTION

Please consult the latest edition of the “MiniMax NT Low NOx Service Manual” for complete service and
repair instructions. Repairs should only be attempted by properly trained service personnel.

P/N 471593 Rev. C 11-1-01

MINIMAX NT LOW NOx HEATER - (Single Voltage)

MiniMAX NT Low NOx, Single Voltage

(Manufactured Date Prior to October 15, 2001)

1
2

3
4

5

6

7

33

24
25

26

27

28
29
32

33
34

35

12

10
11

8

9

30

31

13
14

15

16

17

18

19

20

21

22

23

37
38

48

36

47 46

45

50

49

44

43

39

40

41

42

Rev. C 11-1-01 P/N 471593

p

y

y

y

y

g

g

y

g

g

y

p

g

y

pply

y

g

)

(

)

pp

pp

pp

g

y

(High)

g

p

g

y

p

(

)

(

)

)

)

(

)

ge(

)

p

MiniMax NT Low NOx Single Voltage Replacement parts

(

)

Manufactured Date Prior to October 15, 2001

ITEM DESCRIPTION QTY. 250 400

1 Exhaust Grill 1
2 Gasket, Exhaust Grill 1
3To
4 Exhaust Ass
5 Shut-off Safet

Cover 1 471692 471591

. 1 471995

Switch, Exhaust 1
6Blower 1
7 Gasket, Blower 1
8 Flue Collector Ass
9 Return Manifold Ass

10 Bolt, Heat Exchan
11 Washer, Heat Exchan
12 Fire box Ass
13 Heat Exchan
14 Baffle, Heat Exchan

. 1 472007 472005

.1

er 16

er 16

. 1 471835 471821

er Assy. 1 471785 471838

er 8 / 16 (250 / 400)471641 471640
15 Thermistor Probe 1
16 HI-Limit Thermostat-115° F. 1
17 Hi-Limit Thermostat-150° F. 1
18 Water Pressure Switch 1
19 Main Manifold Ass
20 Ada

ter, Bulkhead Rin

.1

2
21 Adapter, Bulkhead, 2 in. 2
22 Gasket, Fin Tube, Seal 18
23 Flow Valve Ass

.1
24 Gas Pressure Switch 1
25 Sub-Manifold, Gas Su

1
26 Gas Valve-Natural Gas 1
27 Burner Tra
28 I

niter 1 / 2 (250 / 400

Assy. 1 471836 471822

471592
471701

471996
471714
471741
471610

471991
471622
072184

471566
471587
471694
471672
471992
274440
471441
070951
471750
471506
471597
471601

471696

29 Gas Manifold Assy. 1 472003 472001
30 Burner 5 / 8

250 / 400

471668

31 Face Plate 1 471819 471820
32 Jacket, U

er Panel, Left 1

33 Jacket Corner 4

471575
471581

34 Jacket Divider 1 471651 471580
35 Jacket, Lower Panel, Left 1

471647

36 Base 1 471645 471573
37 Jacket Back 1 471669 471574
38 Bracket, Jacket Side 2
39 Jacket, U
40 Jacket, U
41 Jacket, Lower Panel, Ri

er Panel, Right 1
er Subplate 2

ht 1

471768
471576
471767
471577

42 Base Heat Shield 1 471646 471579
43 Control Box Ass

.1
44 Air Pressure Switch
45 Module, I
46 Tem
47 Ri

ht Door Assy.1
48 Left Door Ass
49 Fan S
50 Air Pressure Switch

NA Gas Orifice, 0-2000 Ft

nition Control 1

erature Controller 1

. 1 471659 471726

eed Cross-over Board 1 N/A 471859

Low

Not Shown
NA Thermal Cut-off (Not Shown
NA Transformer, 40 VA

Not Shown

NA Transformer, .5 KVA, Dual Volta

Not Shown

1

1 N/A 471428

5 / 8 (250 / 400

1
1
1

471994
471743
471562
471565
471727

471984
075173
471571
471887

34

Note: Some

P/N 471593 Rev. C 11-1-01

arts are not listed in above, please contact Customer Service Department for detail

MINIMAX NT LOW NOx HEATER - (Dual Voltage)

MiniMAX NT Low NOx, Dual Voltage

(Manufactured Date After October 15, 2001)

1
2

3
4

5

6

7

8

35

24
25

26

27

28
29
32

33

34

35

36

10
11

12

9

30

31

13
14

15

16

17

18

19

20

21

22

23

37
38

39

40

41

48

47

46

45

44

43

42

Rev. C 11-1-01 P/N 471593

p

y

y

y

y

g

g

y

g

g

y

p

g

p

y

pply

y

g

y

(

)

pp

pp

pp

g

y

g

p

g

y

(

)

)

(

)

p

MiniMax NT Low NOx Dual Voltage Replacement parts

(

)

Manufactured Date After October 15, 2001

ITEM DESCRIPTION QTY. 200 250 300 400

1 Exhaust Grill 1
2 Gasket, Exhaust Grill 1
3To
4 Exhaust Ass
5 Shut-off Safet

Cover 1 471885 471692 471886 471591

. 1 472013

Switch, Exhaust 1
6 Blower 1 471938 471884
7 Gasket, Blower 1
8 Flue Collector Ass
9 Return Manifold Ass

10 Bolt, Heat Exchan
11 Washer, Heat Exchan
12 Fire box Ass
13 Heat Exchan
14 Baffle, Heat Exchan

. 1 472008 472007 472006 472005

.Non-ASME 1

er, Non-ASME 16

er 16

. 1 471904 471835 471922 471821

er Assy. Non-ASME 1 471910 471785 471928 471838

er 8/16(200,250,300/400)471642 471641 471896 471640
15 Thermistor Probe 1
16 HI-Limit Thermostat-115° F. 1
17 Hi-Limit Thermostat-150° F. 1
18 Water Pressure Switch 1
19 Main Manifold Ass
20 Ada
21 Ada

ter, Bulkhead Rin
ter, Bulkhead, 2 in. 2

. Non-ASME 1

2

22 Gasket, Fin Tube, Seal 18
23 Flow Valve Ass

.1
24 Gas Pressure Switch 1
25 Sub-Manifold, Gas Su

1
26 Gas Valve-Natural Gas 1
27 Burner Tra
28 I

niter 1
29 Gas Manifold Ass
30 Burner 4/5/6/8

Assy. 1 471905 471836 471923 471981

. 1 472004 472003 472002 472001

200/250/300/400

471592
471701

472014

471714
471883
471610

471991
471622
072184

471566
471587
471694
471672
471992
274440
471441
070951
471750
471506
471597
471601

471696

471668
31 Face Plate 1 471871 471819 471873 471977
32 Jacket, U

er Panel, Left 1

33 Jacket Corner 4

471575

471581
34 Jacket Divider 1 471827 471651 471826 471580
35 Jacket, Lower Panel, Left 1

471647
36 Base 1 471829 471645 471828 471573
37 Jacket Back 1 471861 471669 471874 471574
38 Bracket, Jacket Side 2
39 Jacket, U
40 Jacket, U
41 Jacket, Lower Panel, Ri

er Panel, Right 1
er Subplate, Right 2

ht 1

471768

471576

471767

471577
42 Base Heat Shield 1 471831 471646 471830 471579
43 Control Box Ass

.1
44 Air Pressure Switch 1 471747 471569
45 Module, I
46 Tem
47 Ri

ht Door Assy.1

48 Left Door Ass

NA Gas Orifice, 0-2000 Ft
NA Thermal Cut-off (Not Shown
NA Transformer, 40 VA

nition Control 1

erature Controller 1

. 1 471900 471659 471918 471726

Not Shown)4/5/6/8(200/250/300/400

Not Shown

1
1

472015
471743
471893
471565
471985

471984
075173
471571

36

Note: Some

P/N 471593 Rev. C 11-1-01

arts are not listed in above, please contact Customer Service Department for detail

NOTES

37

Rev. C 11-1-01 P/N 471593

NOTES

38

P/N 471593 Rev. C 11-1-01

NOTES

39

Rev. C 11-1-01 P/N 471593

MiniMax NT Low NOx Heaters

Limited Warranty

Your MiniMax NT Low NOx pool heater is another quality product from Pentair Pool
Products, Inc. and is backed by the following warranty.

1. The following parts are warranted for 5 years from date of purchase:

The MiniMax NT Low NOx cabinet and combustion chamber, the main burners and
burner manifold, the inlet/outlet header and the return header. This warranty does not
cover rusting or corrosion on cabinets or burners that does not affect the heater's
operation.

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2. The following parts are covered for 2 years from date of purchase:

The automatic flow control valve, all controls, heat exchanger, pilot generator and the
pilot assembly.

This warranty only applies to the original purchaser.

3. This warranty shall not apply to any units or parts which have been subject to accident,
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 provided with each unit. Copies of
this manual are available by writing to Pentair Pool Products, Inc., at the address below.

Pentair Pool Products, Inc. assumes no liability except for the repair or replacements of
parts as specified above. Ship defective parts or equipment along with serial number and
purchase date, transportation prepaid to the address below. Purchaser shall be responsible
for freight charges for return of merchandise to purchaser. Some states do not allow
exclusion or limitation of incidental or consequential damages so the above may not apply
to you.

This warranty gives you specific legal rights, and you may also have other rights which
vary from state to state.

HEATER SERIAL NUMBER

(Please Fill In)

Pentair Pool Products, Inc.

1620 Hawkins Ave., Sanford, NC 27330 • [phone]

10951 W. Los Angeles Ave., Moorpark, CA 93021

P/N 471593 Rev. C 11-1-01

• [phone]