Armstrong Flo-Direct User manual

Flo-Direct®
Complete Thermal Exchange
Gas Fired Water Heater Product Manual
This Water Heater has been supplied for this application based upon information provided to Armstrong
at the time the order was accepted.
This Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater has been designed, fabricated
and configured specifically for this installation and as such there may be customized components which
are not specifically addressed within this document.
Supplemental Product Manual’s and Installation and Maintenance Guides specific to the peripheral
components supplied on/with Flo-Direct®Water Heaters are available online at:
http://www.armstronginternational.com/water-heaters-direct-contact-all-models
or by calling Armstrong Toll Free at 1-888-HOT-HOSE.
Model Number ________________________________
Serial Number_________________________________
Ship Date_____________________________________
Installation Guide 706

2
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
What to do if you smell gas.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from an off site telephone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency or the local gas supplier.
Customer Support:
Armstrong Hot Water Group
Phone: [phone]
Fax: [phone]
e-mail: [e-mail]
www.armstronginternational.com
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
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.
Please read and save this installation and maintenance manual. This guide is to be left with
the equipment owner.

3
Table of Contents
Installation Details Form (IDF).............................................................................................................................4
Installation Schematic..........................................................................................................................................5
Product Description Literature.............................................................................................................................7
Introduction ....................................................................................................................................................... 11
Safety Warnings ................................................................................................................................................ 11
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Operating Specifications...........................12
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Standard Materials of Construction ..........12
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Standard Dimensions and Weights ..........12
Armstrong Transfer Pump Component Parts ....................................................................................................13
Armstrong Transfer Pump Operating Specifications .........................................................................................13
Armstrong Transfer Pump Standard Dimensions..............................................................................................13
Armstrong Storage/Supplemental Heater Tank Operating Specifications .........................................................14
Armstrong Storage/Supplemental Heater Tank Standard Materials of Construction.........................................14
Armstrong Storage/Supplemental Heater Tank Standard Dimensions and Weights.........................................14
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater On-Site Commissioning............................15
Assembly & Installation...............................................................................................................................16
Utility Connection ........................................................................................................................................18
Start Up and Tuning ....................................................................................................................................24
Sequence of Operation......................................................................................................................................27
Programmable Logic Controller (PLC) ..............................................................................................................28
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Service & Maintenance.............................29
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Component Identification Diagrams..........31
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Spare Parts...............................................31
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater Fault Diagnosis.........................................35
Warranty Information .........................................................................................................................................40

4
Sample Installation Details Form (must be completed before order processing)
1. Model Number: ______________________ 2. Type of Storage (circle one): Integral or Remote
3. Entering Water Temperature: ____________________°F 4. Leaving Water Temperature: ____________________°F
5. Flow Rate: ____________________GPM 6. Installation Altitude: ____________________
7. Water Pressure: ____________________PSI 8. Gas Pressure: ____________________PSI
9. Inlet Water Train Material (cirlce one): Copper or 304L S.S. or Other: ____________________
10. Ultra Low NOX Burner: Yes _____ No_____ 11. Modulating Burner: Yes _____ No_____
12. Type of Fuel: ____________________ 13. System Voltage: ____________________
Product Technical Detail:
For Remote Storage:
2. Dual Pump: Yes_____ No_____
14. Control Voltage Transformer (circle one): Customer Supplied or Purchase from Armstrong
1. Pump Bypass Material (cirlce one): Copper or 304L S.S. or Other: ____________________
15. Electrical Disconnects (circle one): Customer Supplied or Purchase from Armstrong
3. Storage Tank Included: Yes_____ No_____

5
S5416
Transfer
Pump
Solenoid
Valve
Remote
Storage Tank
Hot
Water
Cold
Water
By-Pass
Figure 5-1.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
This product manual specifically addresses the following assembly components:
• Flo-Direct®CTE gas fired water heater Models 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000,
10000, 11000, 12000, 13000, 14000 and 15000.
• Transfer Pump Assemblies for all models listed above.
• Storage Tanks

6
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
This product manual DOES NOT specifically address the following assembly components:
• Burner Assembly
• Fan/Blower
• Variable Frequency Drive Pump Assembly
For the VFD Pump Assembly, reference Armstrong installation and operation manual, supplied separately.
Burner Assembly Installation and Maintenance, Service and Spare Parts handled directly by MAXON™
Corporation. Phone: [phone], Fax: [phone].
Blower Assembly Installation and Maintenance, Service and Spare Parts handled directly by Cincinnati
Corporation. Phone: [phone], Fax: [phone].
S5417
Fan / Blower
Burner Assembly
Flo-Direct
Remote
Storage Tank
Variable Frequency
Drive Pump Package
Figure 6-1.

7
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Armstrong Flo-Direct®CTE gas fired water heaters offer a complete range of high efficiency, compact, all
stainless steel water heaters which are remarkably dependable, simple in design and operation, and suitable for
a wide variety of hot-water applications.
With standard operating capacities between 1 million and 15 million BTU per hour and customized systems up to
25 million BTU per hour, Flo-Direct®often deliver fuel savings as high as 30-60% when compared to steam/water
heating systems.
With a small footprint, 99.7% or greater heat transfer efficiencies, remarkable dependability, ease of
maintenance, and the ability to operate well with poor water quality Armstrong Flo-Direct®CTE gas fired water
heaters are the product of choice for companies seeking to achieve Energy Conservation Measure (ECM) and
Reduced Carbon Footprint objectives.
Primary Markets include:
Hot Water
Food Process Industries
• Washdown
• Batch Production
• Vessel Filling
• Tank Cleaning
Concrete Plants
• Pre-Heated Water for batch production.
Space Heating
• Greenhouses
Re-Circulated HW for general space heating
• Light Manufacturing/Warehouses
Re-Circulated HW for general space heating
General Industry
• Boiler Make-Up Water
Customized Hot Water System Solutions are our specialty. Multiple orientations, configurations and options are
available.
Hot Water System Solutions which include transfer pumps, storage tanks variable frequency drive (VFD), pump
skid-packaged solutions, hose stations, circulating pumps, downstream digital water temperature controls/loops
with BAS/DDC interface along with a multitude of performance matched components can be application
engineered specifically to meet the projects requirements.
Additonally, where approportiate, Armstrong can integrate engineering services, turn key installation and project
management, system assessment and optimization along with energy conservation measure (ECM) capability
through Armstrong Service Incorporated.

8
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Ultra low Nox option available ≤ 9 ppm
Exhaust temperatures within a few degrees
of the incoming water allow for inexpensive
CPVC or single-wall stainless for ducting
materials.
Flo-Direct is U.S. Patent 5,924,391
Water pressure limit switch and high
temperature switch shut down
the unit for safety if water pressure
fails or is accidentally shut off.
3/16” Plate stainless steel construction
with a 10-year warranty on the
structure and its internals. 2-year
warranty on external components.
Indexability of the top portion to the
bottom allows for flexibility in rotating
for easiest utility hookups. Allows for
ease of internal inspection.
Level controls automatically
control the transfer pump
(included) which delivers
heated water to application.
Standard Low Nox (30-50ppm)
high-efficiency burner/blower for low
carbon monoxide and nitrous oxide
emissions. Complies with even the
most stringent emission standards
and is an ideal element for companies
seeking to reduce their overall carbon footprint.
Standard unit is NSF-5 certified for
food-grade water. CTE Compliant for
enhanced water purity and safety
Modular fuel train using slide out
components for ease of maintenance
or replacement. CSA, UL , CTE and
FM compliant and so certified.
Small footprint because the burner
is installed on top of the unit
“out of the way” and not on the side.
No side clearance required.

9
How the Flo-Direct®Complete Thermal Exchange Gas-Fired Water Heater delivers unrivaled Performance
and Efficiency.
Incoming water is introduced into the top of the water heater through a series of calibrated dispersion nozzles.
Cold water travels down through a bed of multifaceted stainless steel packing rings (Pall Rings) which break the
water into smaller and smaller droplets.
A burner is mounted on top of the unit, firing downward through a centrally located flame tube. The flame tube is
cooled by incoming cold water, and all of the fuel gasses are consumed within this flame tube. The design allows
all combustion to take place within a dry and cool environment, and produces very low levels of nitrous oxide (NO)
and carbon monoxide (CO).
Heat from the flame enters the lower chamber from the bottom of the flame tube, and travels slowly upward
through the packing rings. Efficient heat transfer occurs as the descending water comes in contact with the rising
hot gasses as both pass through the bed of packing rings in opposite directions.
This “rain” of hot water then falls into the lower chamber and is pumped out to a storage tank. Water temperatures
up to 185°F are available within a minimum of 30 seconds after the unit starts. Outlet water temperature is set
with a valve controlling the incoming water flow.
More incoming water results in cooler outlet water temperatures, and less incoming water produces hotter outlet
water temperatures. The products of combustion are vented out of the top of the unit, and this exhaust is typically
within a few degrees of incoming water temperature.
The Result
The Armstrong Flo-Direct®CTE gas fired water heater produces potable hot water instantaneously. There is no
fuel consumed for warm-up or idle time. No energy is lost through steam conversion or within a heat exchanger.
Virtually all of the fuel energy is transferred to the water.
Features
• CTE Compliant
• NSF certified for food-grade water
• No internal moving parts
• Low-temperature exhaust
• Water temperature differential from 10°F to 140°F
• 99.7% or greater efficiency
• Water treatment not required
• Stainless steel construction
• Takes up minimal floor space
• Ten year warranty on structure/two years on all
other components
CTE Technology
Developed from direct contact water heating science that was first introduced more than two decades ago, Com-
plete Thermal Exchange (CTE) has revolutionized high efficiency water heating methods. Today CTE enjoys a
proven record and has rapidly become the new standard in energy savings.
While traditional direct contact water heating offers energy savings from 40% to nearly 60% over conventional
boiler systems, Armstrong Flo-Direct®CTE gas fired water heaters, using CTE technology feature a 99.7% ef-
ficiency rating throughout each phase of its operation cycle. The sustained efficiency of Flo-Direct®CTE gas fired
water heaters are clearly the most energy efficient method of hot water production on the market today.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater

10
No Scale Build-Up
The Flo-Direct®CTE gas fired water heater’s unique design prevents scale build-up because there are no “hot
spots” internally or externally, and because calcium is prevented from completely falling out of suspension during
operation. As a result, if you have hard water entering the Flo-Direct®CTE gas fired water heater, you will have
the same hard water coming out.
Armstrong Flo-Direct®CTE gas fired water heaters meet CTE Standards
CTE direct contact water heaters, such as the Flo-Direct®, meet five standards not found in older, traditional-meth-
od direct contact water heater technology:
1. CTE units maintain a minimum of 99.7% efficiency in all modes of operation not just under optimal conditions.
2. CTE units have multiple thermal passes. Water and the combustion gasses (or heat from the combustion)
come in contact more than once. This ensures all of the heat or energy from combustion is transferred to
the water.
3. CTE units have a dry combustion chamber. This is vital to maintaining complete combustion at all times during
operation.
4. CTE units maintain complete combustion at all times.
5. CTE units must have a “Fail Safe” water integrity system for water quality. In any mode of failure the CTE unit
will maintain the quality of the water coming out of the heater.
Complete Combustion = Complete Water Quality.
While many traditional-method direct contact water heaters spray water directly on the flame – sometimes called
“flame quenching” – Flo-Direct®, using CTE technology, avoids this process altogether. According to the Industrial
Heating Equipment Association’s “Combustion Technology Manual*,” flame quenching promotes incomplete com-
bustion, and produces alcohols, aldehyde, formic acid, higher order acids, carbon monoxide, as well as carbon
dioxide and water vapor. Because it uses CTE technology, Flo-Direct®maintains 99.7% combustion efficiency,
while maintaining water quality at all times. In addition, Flo-Direct®has a built-in fail-safe system for heating water
that maintains water quality despite any type of failure.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
It is impossible to get the full BTU value from the fuel unless you have complete combustion.
Costs for Heating 10,000 Gallons of Water
Type of Heater Typical Sizes
Btu/hour Available
Total
System
Efficiency †
Max.
gpm*
Cost to Heat
10,000
Gallons**
Commercial water
heater (atmospheric
burner)
0.1 - 2.0 MM 70 - 85% 34 gpm $159.93 @ 75%
Steam Boiler 1.0 - 50.0 MM 55 - 75% 833 gpm $184.54 @ 65%
Flo-Direct®
1.0 - 25.0 MM 99.7% 416 gpm $120.31 @
99.7%
Sizing Formulas
gpm x ∆T = AFD Model
2
(AFD model) x 2 = gpm
∆T
(AFD model) x 2 = ∆T
Formula Key
gpm = Gallons per minute
∆T = Temperature rise (°F)
AFD = Armstrong Flo-Direct®
Note: Use the Flo-Direct®sizing tool at www.armstronginternational.com/flo-direct
*Maximum gallons per minute with a 120°F rise using largest heater.
**Direct fuel costs are calculated using $12.00 per MMBtu and a 120°F rise.
†System defined from natual gas in to hot water out.

11
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Introduction
The Flo-Direct®CTE gas fired water heater assembly covered by this IOM features installation, commissioning,
operation and general maintenance detail for the water heater, transfer pump and optional storage tank.
Each Flo-Direct®CTE water heater is serialized and the serial number is maintained on file in the Technical
Department at Armstrong.
Further technical, component and dimensional detail is available for each Flo-Direct®CTE water heater
Model/Assembly.
For any installation, operational or maintenance detail not covered in this Product Manual please call Armstrong
Toll Free at 1-888-HOT HOSE and reference this serial number.
Supplemental Product Manual’s and Installation and Maintenance Guides specific to the peripheral components
supplied on/with Flo-Direct® water heaters are available online at:
http://www.armstronginternational.com/water-heaters-direct-contact-all-models
Safety Warnings
Flo-Direct®CTE water heaters are precision engineered and crafted with pride to deliver years of energy savings
and superior performance provided:
1. They are installed, commissioned, operated and maintained in accordance with the recommendations
provided in this Product Guide and accepted plumbing, pipe-fitting, and natural fuel management practices.
2. Periodic attention is given, as necessary, to maintain the product, the accessory fittings & components and
the plumbing/distribution system in good functional order.
3. The Flo-Direct®CTE water heater uses natural gas or other highly flammable fuel. It is essential that
generally accepted safety measures are deployed accordingly. At any time if the odor of gas is detected
immediate action in accordance with the SAFETY WARNING included in the inside front cover of this
product manual is enacted.

12
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Flo-Direct®CTE Water Heater Operating Specifications
Flo-Direct®CTE Water Heater Standard* Materials of Construction
*Optional/Custom Materials of Construction available upon request.
Flo-Direct®CTE Water Heater Standard Dimensions and Weights
Operating Specifications
Gas Supply Pressure 2 - 6 psig / .14 - .41 bar
Dynamic Water Supply Pressure Constant water pressure (+/-5 psi variation maximum) within a minimum of 30 psig/2 bar
and a maximum of 100 psig/6.8 bar range is required for optimum performance.
Maximum Inlet Water Temperature 120°F (49°C)
Minimum Inlet Water Temperature 32°F (0°C)
Maximum Effective Outlet Temperature 185°F (85°C)
Component Material
Upper and Lower Canister Type 304 Stainless Steel #10 Glass Finish
Inlet Gas Train Piping Malleable Iron with Standard Yellow Finish
Inlet Water Train Piping Copper with Brass/Bronze Fittings
Spray Ring Type 304/316 Stainless Steel
Canister Gaskets Warco White
Flame Tube Type 304 Stainless Steel
Pall Rings Type 304 Stainless Steel
Dimensions and Weights
Model
Connections* Dimensions Weight Btu/hour1 2 A B C D E
in mm in mm in mm in mm in mm in mm in mm lb kg
1000 1 25 1 25 95 2413 71 1803 39 991 24 610 8 203 825 375 1,000,000
1500 1 25 1 25 97 2464 73 1854 41 1041 26 660 8 203 850 386 1,500,000
2000 1-1/2 40 1-1/2 40 100 2540 76 1930 44 1118 30 762 10-3/4 273 1500 680 2,000,000
3000 1-1/2 40 1-1/2 40 100 2540 76 1930 44 1118 36 914 12 305 1600 725 3,000,000
4000 2 50 2 50 104 2642 80 2032 48 1214 40 1016 14 356 2000 907 4,000,000
5000 2-1/2 65 2 50 127 3226 97 2464 65 1651 44 1118 14 356 2500 1136 5,000,000
6000 3 80 2 50 132 3353 100 2540 70 1778 47 1194 18 457 2900 1316 6,000,000
7000 3 80 2 50 139 3531 107 2718 77 1956 50 1270 18 457 3200 1455 7,000,000
8000 3 80 2 50 139 3531 107 2718 77 1956 50 1270 18 457 3200 1455 8,000,000
9000 3 80 2 50 169 4293 139 3531 107 2718 60 1524 20 508 5000 2273 9,000,000
10000 3 80 2 50 181 4597 151 3835 119 3023 61 1549 20 508 5200 2405 10,000,000
11000 4 100 3 80 181 4597 151 3835 119 3023 61 1549 22 559 5500 2495 11,000,000
12000 4 100 3 80 181 4597 151 3835 119 3023 61 1549 22 559 5500 2495 12,000,000
13000 4 100 3 80 192 4877 161 4089 129 3277 70 1778 24 610 7000 3175 13,000,000
14000 4 100 3 80 192 4877 161 4089 129 3277 70 1778 24 610 7000 3175 14,000,000
15000 4 100 3 80 192 4877 161 4089 129 3277 70 1778 24 610 7000 3175 15,000,000

13
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Specifications
Model
No
Maximum Flow Rate Inet Connection Outlet Connection Flow Control Valve Bypass Valve Pump Power
gpm m3/hr in mm in mm in mm in mm hp kW
TP-50 50 11.4 1-1/2 40 1-1/2 40 1 25 1 25 2 1.49
TP-90 90 20.4 1-1/2 40 2 50 1-1/2 40 1-1/2 40 3 2.24
TP-135 135 30.7 2 50 2-1/2 65 2 50 1-1/2 40 5 3.73
TP-200 200 45.4 2-1/2 65 3 80 2 50 2 50 7.5 5.59
TP-275 275 62.5 2-1/2 65 4 100 2-1/2 65 2 50 10 7.46
TP-350 350 79.5 3 80 4 100 3 80 2 50 10 7.46
Component Material
Piping Type L hard copper
Braided Flex Hose Stainless Steel
Pump Stainless Steel, TEFC Motor
Bypass Valve Bronze, 110 VAC Solenoid
Globe Valve Bronze
Stand Carbon Steel
Armstrong Flo-Direct®CTE Transfer Pump Assembly
Armstrong Fo-Direct®CTE Transfer Pump Assembly Materials of Construction

14
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Specifications
Model No
Fiberglass Reinforced
Plastic Nominal Tank
Storage Volume
Number of Inlet
Connections
for AFD Water
Heaters
Nominal Piping Connections
Height Diameter Weight
(Empty)
Inlet Outlet
gallons m3in mm in mm in mm in mm lb kg
RST-1001 1000 3.785 1 2 NPT 50 2 NPT 50 94 2388 64 1626 1200 544
RST-1002 1000 3.785 2 2 NPT 50 2 NPT 50 94 2388 64 1626 1200 544
RST-3001 3000 11.36 1 2-1/2 NPT 65 3 FLG 80 146 3704 88 2235 2000 907
RST-3002 3000 11.36 2 2-1/2 NPT 65 3 FLG 80 146 3704 88 2235 2000 907
RST-5001 5000 18.93 1 3 NPT 80 4 FLG 100 150 3810 112 2845 2600 1179
RST-5002 5000 18.93 2 3 NPT 80 4 FLG 100 150 3810 112 2845 2600 1179
Specifications
Design Standard ASTM D49097-00
Maximum Pressure Atmospheric
Vacuum None
Maximum Temperature 180°F (82.2°C)
Specific Gravity 1.2
Seismic Code / Design None
Wind Load 0 MPH / KPH
Immersion Heater Port 2” NPT
Sight Glass Ports (2) 1” NPT
Insulation Thicknesss 2” (50 mm)
Component Material
Structural Layer Fiber Reinforced Plastic
Structural and Liner Resin DERAKANE 441-400
Exterior Layer Resin Isophthalic Polyester
Tank Finish Gel Coat with U.V. Inhibitor
Color Gray (AT071)
Tank Fittings Fiber Reinforced Plastic
Vent Fiber Reinforced Plastic
Manhole and Cover Fiber Reinforced Plastic
Manhole Cover Bolts Stainless Steel
Manhole Gasket EPDM
Hold Down and Lifting Lugs Powder Coated Carbon Steel
Armstrong Supplemental Storage Tank Standard Dimensions and Weights
Armstrong Supplemental Storage Tank Design Data
Armstrong Supplemental Storage Tank Materials of Construction

15
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Flo-Direct®CTE Water Heater On-Site Commissioning
The On Site Commissioning protocol for the Flo-Direct®CTE water heater consists of three integral elements:
• Assembly and Installation
• Utility Connection
• Start Up and Tune Up
Factory Technician Commissioning is optionally available. Please consult factory toll free at 1-888-468-4673
for a quotation.
On Site Commissioning should be carried out in strict accordance to the following directives and should be
performed by designated, qualified and competent personnel.
Failure to properly commission the Flo-Direct®CTE water heater, the transfer pump, the storage tank, any
peripheral components supplied with the assembly or the system in accordance with this product manual
voids all warranties and performance guarantees.
Utility connections should be performed by a licensed professional in accordance with prevailing local, state and
national codes and regulations.
Failure to perform the utility connections in accordance with this product manual and/or prevailing local, state and
national codes and regulations voids all warranties and performance guarantees.
On-Site Commissioning
Assembly and Installation
Flo-Direct®CTE water heaters are assembled and pressure and performance tested at the factory*. Flo-Direct®
CTE water heaters are typically delivered to the installation site with the upper canister, lower canister and top
plate separated and if configured accordingly, the transfer pump assembly and storage tank as individual
components indicated below.
*Important Note: Post reassembly “tuning up” is a mandatory requirement due to on site variable installation
conditions.
Lower Canister
Assembly
Gasket
Upper Canister
Assembly
Gasket
Top Plate
Assembly
S5602
Transfer Pump
Assembly
S5603
Storage Tank

16
Assembling the Upper Canister and Top Plate
1. Place the upper canister section on a firm level surface.
2. Align the interface gasket with the bolt holes on the upper
canister flange. Reference Figure 16-2 lower canister).
3. Deploying the appropriate materials handling equipment
place the top plate atop the upper canister ensuring
that the bolt holes and gasket remain aligned. Figure 16-1.
4. Insert the attachment bolts (packaged with the gaskets)
into the canister retaining holes and thread on the nuts
and washers and secure. A liberal application of an
anti-seize lubricant on the bolt threads is strongly
recommended.
5. Tighten nuts/bolts using a cross pattern style.
Retightening may be required over time.
Assembling the Upper and Lower Canister
6. Place the lower canister section on a firm level surface.
7. Align the interface gasket with the bolt holes on the lower
canister flange as indicated in Fig 16-2.
Note: Upper canister and lower canister are marked to
indicate suggested indexing.
8. Deploying the appropriate materials handling
equipment place the upper canister atop the lower
canister ensuring that the bolt holes and gasket remain
aligned. Figure 16-3.
9. Insert the attachment bolts (packaged with the gaskets)
into the canister retaining holes and thread on the
nuts and washers. A liberal application of an anti-sieze
lubricant on the bolt threads is strongly recommended.
10.Tighten nuts/bolts using a cross pattern style.
Retightening may be required over time.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Figure 16-1.
Figure 16-2.
Figure 16-3.
Ensure that packing rings are evenly distributed and
in no way are interfering with the spray nozzles.

17
11. Connect the “Exhaust Outlet” (Figure 17-1) to an exhaust
duct*. The low temperature exhaust feature of Flo-Direct®
CTE water heaters allow for either a CPVC or seamless
stainless steel exhaust duct work.
*Note: It is important that the installation does not in any
way restrict the exhaust flow.
• The exhaust duct work must not “bush down” and must
be the same size as the units exhaust outlet
connection or larger.
• If horizontal duct runs are required the minimum angle is
45 degrees.
• If a rain guard is installed on the exterior portion of the
exhaust duct it must not restrict the exhaust gas flow.
• Models 1000 and 1500 must include a rubber “boot” to
seal the extension to the exhaust outlet. Models 2000
and larger have a flanged connection.
Transfer Pump
Connect the Transfer Pump (Figure 17-2) to the lower canister water outlet using the suction hose provided. The
throttling valve (Figure 17-3) controls the pump back pressure.
The outlet from the transfer pump assembly should be piped to the top of the supplemental storage tank.
Note: The pipe should not be routed into the bottom of the storage tank to prevent back flow.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Figure 17-1.
Throttling
Valve
Transfer Pump
Assembly
Suction Hose
Heater Outlet
Flo-Direct
S5604
Figure 17-2. Figure 17-3.
Warning: It is imperative that the transfer pump installation include either the flexible hose as
supplied by Armstrong OR a suitable equivalent which isolates vibration.

18
Storage Tank
The Armstrong storage tank has the following connection points:
• Inlet connections to accomodate upto two (2) Flo-Direct®CTE water heaters
• An outlet connection to the system pump
• An optional connection point for an immersion heater*
• An optional connection for a fluid level sight glass
• An optional connection for re-circulation system return piping.
• Connections for upper and lower float switch assemblies
* Note: For the purposes of this Product Manual it is presumed that a supplemental immersion heater is NOT
included. For Immersion Heater installation and wiring detail call the Armstrong Technical Department at
1-888-HOT HOSE.
Automatic Mode: The unit is started when the water level in
the storage tank falls below the lower float switch. The unit
stops when the water level reaches upper switch is made.
Manual Mode: The unit will run continuously until manually
switched off.
Utility Connections
Water
Flo-Direct®CTE water heaters are supplied as standard with
a Water Train (Figure 18-1) comprised of lead free soldered
copper pipe work and associated fittings with brass and bronze
accessory components. The Water Train is supplied pre-piped
and pressure tested.
A water inlet Flow Control Valve (Figure 18-2) is supplied
as standard.
Connect the Water Train ensuring that the inlet pipework which
connects to the Water Train inlet is sized appropriately for the
system flow requirement.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Figure 18-1.
Figure 18-2.

19
Fuel
While alternate fuel supplies can be used with Flo-Direct®CTE
water heaters this product manual presumes natural gas
supplied by a local utility. The Flo-Direct®CTE gas fired water
heater includes an integral gas pressure regulator. The gas supply
to the water heater should be within the following range:
• Minimum gas pressure is 2 PSIG.
• Maximum gas pressure is 6 PSIG
• OPTIMUM gas pressure is 4-5.5 PSIG
Flo-Direct®CTE water heaters are supplied as standard with
a gas train (Figure 19-1) comprised of malleable iron with a
yellow finish. The fuel train is supplied pre-piped and
pressure tested.
The fuel train includes the following components: (Figure 19-2)
• A low gas pressure switch assembly
• A proof of valve closure switch assembly
• A high gas pressure switch assembly
• A gas flow adjustment mechanism
• Dual blocking valves
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Figure 19-1.
Figure 19-2.

20
1. Connect the upper and lower canister gas train sections
at the union provided (Figure 20-1)
2. Connect the gas supply to the Fuel Train inlet using a
standard union connection.
Power/Electrical
Flo-Direct®CTE water heaters are supplied as standard with
an appropriately NEMA rated Enclosure (Figure 20-2) which
contains the primary power supply and component wiring
connection points. A variety of power supply voltages
and internal connection options are available.
For the purposes of reduced complexity this Product Manual
presumes the optimum 460 Volt 3 Phase Power supply.
Note: A 230 Volt Power Supply can also be used BUT the Motor connections must be adapted accordingly.
Consult Factory for further detail.
Flo-Direct®Complete Thermal Exchange Gas Fired Water Heater
Figure 20-1.
Figure 20-2. Figure 20-3.