Pure Humidifier GX Series User manual

TM
READ AND SAVE THESE INSTRUCTIONS
Standard Water
GX Series
Gas Fired Exchanger Humidifier
Installation Instructions
Operation and Maintenance Manual
FOR YOUR SAFETY:
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
WARNING:
Improper installation, adjustment, alteration, service or maintenance can cause injury or property
damage. Refer to this manual. For assistance or additonal information consult a qualified installer,
service agency, or the gas supplier.
WARNING:
If the information in this manual is not followed exactly, a fire or explosion may result, causing property
damage, personal injury, or loss of life.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do not use any telephone in your building.
Immediately call your gas supplier from a neighbor’s telephone.
Follow the gas supplier’s instructions. If you cannot reach your gas supplier, call the fire department.
IMPORTANT: Read and save this guide for future reference. This
guide to be left with equipment owner.
ETL/ETLC Listed #43438 To “IAS 12-94 Gas Fired Humidifier”
Our results are comforting
PURE HUMIDIFIER® and INTAC® are registered trademarks of PURE Humidifier Co.
Form No: GXOM-6-2023

TM
To the User of PURE Humidifier Co.’s
GX Series Humidifiers
We at PURE Humidifier Co. thank you for choosing one of our quality products. PURE Humidifier Co. GX Series humidifiers
are models of simplicity to install, operate and maintain. However, they must be maintained to provide maximum operating
efficiency.
PLEASE READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY. PROPER OPERATION AND HUMIDITY CONTROL
IS POSSIBLE ONLY WITH PROPER INSTALLATION AND MAINTENANCE.
The GX Series Humidifier utilizes a Tri-Probe conductive type water control system, which is designed for use with standard
(hard or soft) tap water. Use of demineralized, deionized or reverse osmosis water will cause a failure of the water level
control system and void the warranty. PURE Humidifier Co.’s GXDDR Series should be installed on applications that require
demineralized, deionized or reverse osmosis water.
High chloride content in feed water can cause chloride stress cracking and chloride pitting in stainless components. Chloride
stress corrosion cracking (CSCC) and chloride pitting of stainless steel components is not covered by warranty. Do not use
hydrochloric acid descalers or bleach to clean the tank. Consult the factory if you are unsure about which chemical descaler
to use.
To ensure proper installation of this product, it must be installed by qualified HVAC and electrical contractors, and must be
in compliance with local, state, federal, and governing codes. If installed improperly this product may cause damage to
property, severe personal injury, or death as a result of electric shock, burns, and/or fire.
Do not adjust any components inside humidifier control box without consulting the factory.
For indoor installation in conditioned paces only unless supplied with an outdoor enclosure.

TM
Table of Contents
TM
Introduction
Warnings ……………………………………………………………………………………….....
Overview
Features ………………………………………………………………………………………......
Capacities, Electrical & Weights ………………………………………………………………..
GX-3, GX-4 Dimensions & Layout ……………………………………………………………...
GX-8 Dimensions & Layout …………………………………………………………................
GX-12 Dimensions & Layout ..…………………………………………………………………..
Installation
Installation & Location …………………………………………………………………….…......
Drain Pan Mounting ……………………………………………………………………….….....
Electrical, Combustion & Ventilation Air ……………………………………………………….
Gas Piping Installation ……………………………………………………………………….….
Venting …………………………………………………………………….................................
Sealed Combustion ………………………………………………………………….….............
GX-8 Exhaust Manifold ……………………………………………………………….…….......
GX-12 Exhaust Manifold …………………………………………………………………….…..
Water Supply & Drain Piping ……………………………………………………………………
Supply Piping Examples …………………………………………………………………….…..
Operation
Modulating Control Operation …..……..………………………………………………….…....
GX Pre-Startup Checklist …………………………………………………………………….….
GX Startup Procedure…..……..………………………………………………….….................
GX Burner Startup Procedure ……………………………………………………….……........
Troubleshooting ……………………………………………………………………………….....
Burner Troubleshooting & Maintenance …..……..…………………………………………….
Burner Flame Controller Troubleshooting …..……..…………………………………………..
Maintenance
Tool Requirements and Torque List ………………………………………….…………….......
GX Maintenance ………………………………………………………….………….................
Exchanger Gasket Replacement ………………………………….……….............................
Cover Gasket Replacement Instructions ……………………………………….…………......
Maintenance Notes ……………………………………………………………….…………......
Spare Parts
GX-3 & GX-4 Exploded Parts Drawing ……………………………………………….……….
GX-3 & GX-4 Parts List …………………………………………………………………….…...
GX-8 Exploded Parts Drawing ……………………………………………….………..............
GX-8 Parts List …………………………………………………………………….…................
GX-12 Exploded Parts Drawing ……………………………………………….………............
GX-12 Parts List …………………………………………………………………….…..............
Modulating Burner Exploded View ……………………………………………….………........
Modulating Burner Gun Assembly Exploded View …………………………………………...
Modulating Burner Parts List ..............................................................................................
On/OffBurner Exploded View ……………………………………………….………...............
On/OffBurner Gun Assembly Exploded View …………………………………………...........
On/OffBurner Parts List .....................................................................................................
Warranty ……………………………………………………………………………………….…………....
1-2
3
4
5
6
7
8
9
10
11-12
13-15
16
17
18
19
20
21-22
23
24
25-26
27
28
29
30
31
32
33
34-35
36
37
38
39
40
41
42
43
44
45
46
47
48

TM
Warnings
PLEASE READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY. PROPER OPERATION AND HUMIDITY CONTROL
IS POSSIBLE ONLY WITH PROPER INSTALLATION AND MAINTENANCE.
Improper installation, adjustment, alterations, service, maintenance, or use can cause carbon monoxide poisoning, an
explosion, fire, electrical shock, or other conditions which may cause property damage, personal injury or loss of life.
Consult a qualified installer, service agency, local gas supplier, or your distributor or branch for information or assistance.
The qualified installer or agency must use only factory authorized and listed kits or accessories when modifying this product.
A failure to follow this warning can cause electrical shock, fire, personal injury, or loss of life.
WARNINGS
RECEIVING
Inspect humidifier and accessories upon arrival for damaged, missing, or improper parts. If there is a problem, call PURE
Humidifier Co.
SERVICING
Disconnect main power before servicing or maintaining humidifier.
The humidifier system including the humidifier tank, steam supply piping, condensate piping and steam distribution grid can
be extremely hot and can cause burns if touched.
Do not use hydrochloric acid descalers or bleach to clean the tank. Consult the factory if you are unsure about which
chemical descaler to use.
ELECTRICAL
Electrical work should be done by qualified electrical contractors and must be in compliance with local, state, federal, and
governing codes.
PLUMBING
Plumbing and pressurized steam work should be done by qualified installers and must be in compliance with local, state,
federal, and governing codes.
Drain and overflow water can be 212°F (100°C). If you are not using a DCT-927 Drain Tempering Kit, allow the water to cool
before draining tank.
This humidifier produces steam at atmospheric pressure. Do not install any components between humidifier tank and steam
distribution grid which can block or restrict steam flow.
LOCATION
Do not mount on hot surfaces.
Do not mount on vibrating surfaces.
MAKEUP WATER
High chloride content in feed water can cause chloride stress cracking and chloride pitting in stainless components. Chloride
stress corrosion cracking (CSCC) and chloride pitting of stainless steel components is not covered by warranty.
Use of mineralized (hard or soft) tap water will cause fill valve failure and void the warranty. PURE Humidifier Co.’s GX
Series should be installed on applications that require tap water.
Do not adjust any components inside humidifier control box without consulting the factory.
For indoor use only unless supplied with an Outdoor Enclosure.
1

TM
GAS
Application of this humidifier should have special attention given to vent sizing and material, gas input rate, and unit sizing.
Improper installation or misapplication of the humidifier can require excessive servicing or cause permanent component
failure.
The installation must conform to the requirements of the authority having jurisdiction, or in the absence of such requirements,
to the National Fuel Gas Code, ANSI Z223.1 (latest edition). In Canada, the installation of this unit must comply with
local plumbing or waste water codes and other applicable codes and with the current code CAN/CGS-B149.1 “Installation
Code for Natural Gas Burning Appliances and Equipment or CAN/CGA-B149.2 “Installation Code for Propane Burning
Applications and equipment.”
Do not install in potentially explosive or flammable atmospheres laden with grain dust, sawdust, or similar airborne materials.
Installation of humidifier in high humidity or salt water atmospheres will cause accelerated corrosion, resulting in a reduction
of the normal lifespan of the unit.
Humidifier must be located in a conditioned space.
To prevent premature heat exchanger failure, do not locate ANY GX unit in areas where chlorinated, halogenated or acid
vapors are present in the atmosphere.
Locate the humidifier in an area clear of combustible materials, gasoline, and other flammable vapors and liquids.
When working on equipment, observe precautions in this literature, tags, and labels attached to or shipped with the unit,
and other safety precautions that may apply. Have fire extinguisher available during startup, adjustment procedures,
and service calls.
Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the
appliance and to replace any part of the control system and any gas control which has been under water.
Do not lift humidifier by gas controls or gas manifold.
Should overheating occur, or the gas supply fail to shut off, shut offthe manual gas valve to the appliance before shutting
offthe electrical supply.
Do not locate units in tightly sealed rooms or small compartments without provision for adequate combustion air and
venting. Combustion air must be supplied to the confined space through a minimum of two permanent openings in the
enclosure, with at least one near the bottom. They should provide a free area of one square inch per 1000 BTU per hour
input rating of the unit with a minimum of 100 square inches for each opening, whichever is greater. Refer to Venting
Installation information on pages 8 & 9.
Warnings (Con’t)
TM
2

TM
Features
1. Tri-Probe Sensor
2. 1/4”-NPT Water Inlet & Strainer
3. Over Temperature Cut-Out Switch
4. Flusher & Overflow Piping
5. 3/4” Motorized Drain Valve
6. Control Panel
7. INTAC®PLC Controller
8. Support Legs
9. Burner Assembly
10. Exhaust Connection
11. Steam Outlet Connection
FEATURES
1
2
3
4
5
6
7
8
9
10
11
3

TM
Capacities, Electrical & Weights
This humidifier is a forced combustion type that can be used with natural gas or liquid propane. The burner can be easily
removed to access the side entry exchanger(s) for cleaning. It is designed to work with low-pressure gas between 5” W.C.
up to 14” W.C.
Standard Water
Unit Model No.
Steam Capacity
lbs/hr (kg/hr)
No. of
Burners *BTU Input
#Exhaust
Manifold
Vent Size
(cm)
Shipping Weight Operating Weight
(kg)
120 Volt, 60 Hz
Full Load
Amps
GX-3 110 (49.9) 1 150,000 4” (10.2) 201 lbs (91.2) 420 lbs (190.5) 5.0
GX-4 300 (136.1) 1 400,000 4” (10.2) 390 lbs (176.9) 710 lbs (322.1) 5.0
GX-8 600 (272.2) 2 800,000 6” (15.2) 827 lbs (375.1) 1391 lbs (630.9) 10.0
GX-12 900 (408.2) 3 1,200,000 8” (20.3) 1125 lbs (510.3) 2072 lbs (939.9) 15.0
† Actual humidifier capacity may vary due to the heat loss from the humidifier reservoir. The ambient air temperature,
air velocity and injection tube system will affect the rate of heat loss from the reservoir.
* Altitude adjustment:
100% up to 2000’
Over 2000’, 4% de-rate per 1000’
# Vent Size is larger than connection size.
Standard Water
Unit Model No.
Water Volume in
Gallons (Liters)
GX-3 22 (83.3)
GX-4 48 (181.7)
GX-8 94 (355.8)
GX-12 143 (541.3)
Unit Capacities in Pounds per Hour (Kg/Hr) †
Weights in lbs (kg) and Electrical Specification
Reservoir Water Volume in Gallons (Liters)
4

TM
Dimensions
GX-3 & GX-4
Required Clearance:
For recommended service and maintenance purposes
the following clearances should be maintained:
Right side, see Top View for required clearance
Front side, NEC requires 36” clearance to
control cabinet
Left side, 6” for access
Rear, 6” for access
Top, 12” for cover and Tri-Probe removal
Heat exchangers have a top and bottom. There is a break (crease) on the bottom side of the heat exchanger. Do not install heat
exchanger upside-down.
All dimensions are approximate and subject to change at manufacturer’s discretion.
Standard Water
Unit Model No. Dim. “A” Dim. “B” Dim. “C” Dim. “D” Dim. “E” Dim. “F” Dim. “G” Dim. “H”
GX-3 34.18” (86.8) 20.46” (52.0) 13.84” (35.2) 24.0” (60.9) 45.9” (116.5) 3/4”-NPT 3.0” (7.62) 50.0” (127.0)
GX-4 54.0” (137.2) 30.1” (76.5) 13.84” (35.2) 24.0” (60.9) 54.7” (138.9) 3/4”-NPT 3.0” (7.62) 66” (167.6)
Unit Dimensions in Inches (cm)
7.8”
(19.8)
“A”
8.0”
(20.3)
“B”
“E”
“H”
Clearance required for
exchanger removal
“F”
Gas Inlet
“G”
Exhaust
Connection
2.8”
(7.1)
“C”
“D”
Steam Outlet Connection
(Size and Qty. will vary with
application)
Top View
Right Side ViewFront View
5

TM
Dimensions
GX-8
Required Clearance:
For recommended service and maintenance purposes
the following clearances should be maintained:
Right side, see Top View for required clearance
Front side, NEC requires 36” clearance to
control cabinet
Left side, 6” for access
Rear, 6” for access
Top, 12” for cover and Tri-Probe removal
Heat exchangers have a top and bottom. There is a break (crease) on the bottom side of the heat exchanger. Do not install heat
exchanger upside-down.
All dimensions are approximate and subject to change at manufacturer’s discretion.
Standard Water
Unit Model No. Dim. “A” Dim. “B” Dim. “C” Dim. “D” Dim. “E” Dim. “F” Dim. “G” Dim. “H”
GX-8 54.0” (137.2) 30.1” (76.5) 32.5” (82.6) 24.0” (60.9) 54.7” (138.9) 1”-NPT 3.0” (7.6) 66.0” (167.6)
Unit Dimensions in Inches (cm)
7.8”
(19.8)
“A”
9.0”
(22.9)
“H”
Clearance required for
exchanger removal Top View
“B”
“E”
“F”
Gas Inlet
“G”
Exhaust
Connection
Right Side View
5.6”
(14.2)
“C”
“D”
Steam Outlet Connection
(Size and Qty. will vary with
application)
Front View
6

TM
Dimensions
GX-12
Heat exchangers have a top and bottom. There is a break (crease) on the bottom side of the heat exchanger. Do not install heat
exchanger upside-down.
All dimensions are approximate and subject to change at manufacturer’s discretion.
Unit Dimensions in Inches (cm)
Standard Water
Unit Model No. Dim. “A” Dim. “B” Dim. “C” Dim. “D” Dim. “E” Dim. “F” Dim. “G” Dim. “H”
GX-12 54.0” (137.2) 30.1” (76.5) 43.5” (110.5) 24.0” (60.9) 55.8” (141.1) 1-1/4”-NPT 3.0” (7.6) 66.0” (167.6)
“D”
“C”
5.6”
(14.2)
Steam Outlet Connection
(Size and Qty. will vary with
application)
Front View
“F”
Gas Inlet
“G”
Exhaust
Connection
Right Side View
Required Clearance:
For recommended service and maintenance purposes
the following clearances should be maintained:
Right side, see Top View for required clearance
Front side, NEC requires 36” clearance to
control cabinet
Left side, 6” for access
Rear, 6” for access
Top, 12” for cover and Tri-Probe removal
7.8”
(19.8)
“A”
9.0”
(22.9)
“H”
Clearance required for
exchanger removal Top View
“B”
“E”
7