Heat Transfer TX Series User manual

Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 1of 33
Phone: [phone] Website: www.dhtnet.com
Installation, Operation, and
Maintenance Manual
TX Indirect Water Heater
This manual applies to the following models:
Product Information:
This user manual must always accompany the specific unit as recorded below.
Model #:
Serial #:
Installation Date:
Wholesaler Name:
Contractor Name:
Additional Information:
Latest Update: August 11, 2020
DISCLAIMER
The information contained in this document is subject to change without notice from Diversified Heat Transfer, Inc. (DHT). DHT makes no
warranty of any kind in respect to this material, including, but not limited to, implied warranties of merchantability and fitness for a particular
application. DHT is not liable for errors appearing in this document, nor for incidental or consequential damages occurring in connection with
the furnishing, performance, or use of these materials.
NOTE:
TX-40
TX-50
TX-80
TX-110
The surfaces of these products contacted by
potable (consumable) water contain less than
0.25% lead by weight as required by the Safe
Drinking Water Act, Section 1417.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 2of 33
Phone: [phone] Website: www.dhtnet.com
TO THE INSTALLER: This manual is the property of the owner and must be affixed near the water heater
for future reference.
NOTE:
TO THE OWNER: This water heater should be inspected annually by a qualified Service Agency.
NOTE:
TO THE OWNER: Register the water heater in order to get the limited lifetime warranty within 90 days.
Improper installation, adjustment, alteration, service or maintenance can cause injury or property
damage. Refer to this manual. For assistance or additional information, consult a qualified Installer or
Service Agency.
FOR YOUR SAFETY:
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance. Installation and service must be performed by a qualified Installer or Service Agency.
Table of Contents
SECTION 1: SAFETY ...................................................................................................................................... 3
Relief Valve Requirements........................................................................................................................ 3
SECTION 2: PRODUCT SELECTION/PERFORMANCE.................................................................................... 4
SECTION 3: TANK SPECIFICATIONS ............................................................................................................. 6
SECTION 4: INSTALLATION & PIPING .......................................................................................................... 9
Location of the TX Series Water Heater.................................................................................................... 9
Piping Installation Instructions ................................................................................................................. 9
Tank Installation ..................................................................................................................................... 14
Piping Installation Instructions For Use With A Steam Boiler ................................................................ 16
SECTION 5: ELECTRICAL AND CONTROLS WIRING.................................................................................... 17
SECTION 6: MAINTENANCE ....................................................................................................................... 23
Water Heater Maintenance ................................................................................................................... 23
Troubleshooting ..................................................................................................................................... 24
Parts and Accessories ............................................................................................................................. 26
SECTION 7: WARRANTY............................................................................................................................. 27
SECTON 1: SAFETY

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 3of 33
Phone: [phone] Website: www.dhtnet.com
The warranty on this water heater is in effect only when the water heater is installed and operated in
accordance with these instructions. The manufacturer of this water heater will not be liable for any
injury or property damage resulting from failure to comply with these instructions.
This water heater must be installed strictly in accordance with the instructions enclosed, and local
electrical, fuel and building codes. It is possible that connections to the water heater or the water heater
itself may develop leaks. IT IS THEREFORE IMPERATIVE that the water heater be installed so that any
leakage of the tank or related water piping is directed to an adequate drain in such a way that it cannot
damage the building, furniture, carpeting, adjacent areas, lower floors of the structure, or other
property subject to water damage. This is particularly important if the water heater is installed in a
multi-story building, on finished flooring, or carpeted surfaces. DHT WILL NOT BE HELD LIABLE for
damage caused by water from the water heater, pressure relief valve, or related fittings. Closets without
drains and carpeted areas are examples of unsuitable locations for any water heater. Select a location as
centralized within the piping system as possible.
The heater should be located in an area not subject to freezing temperatures in any location
selected. It is recommended that a suitable drain pan be installed under the water heater.
This pan shall be a minimum of 50mm (2 in.) deep and have a diameter that is a minimum of
50mm (2 in.) greater than the diameter of the water heater.
Suitable piping shall connect the drain pan to a properly operating floor drain.
SECTON 1.1: Relief Valve Requirements
FOR YOUR SAFETY:
To reduce the risk of excessive pressures and temperatures in this water heater, install temperature and
pressure protective equipment required by local codes. It should be no less than a combination
temperature and pressure relief valve certified by a nationally recognized testing laboratory that
maintains periodic inspection of production of listed equipment or materials, as meeting the latest
edition of ANSI Z21.22.
Requirements for Relief Valves and Automatic Gas Shut-off Devices for Hot Water Supply Systems:
This valve must be marked with a maximum set pressure not to exceed the marked MAXIMUM working
pressure of the water heater (150 PSI).
How to Install:
1. Install the valve into an opening provided and marked for this purpose in the water heater.
2. Orient it or provide tubing so that any discharge from the valve will exit only within 6 inches
above, or any distance below the structural floor and cannot contact any live electrical part.
3. The discharge opening must not be blocked or reduced in size under any circumstances.
4. The end of the relief pipe opening should terminate near a floor drain or other suitable location
not subject to blocking or freezing.
5. DO NOT thread, plug, or cap the relief pipe opening.
:

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 4of 33
Phone: [phone] Website: www.dhtnet.com
Water temperatures over 125°F can cause severe burns instantly or
death from scalds.
Children, disabled, and elderly are at the highest risk of being
scalded.
See instruction manual before setting temperature at water
heater.
Feel water before bathing or showering.
Temperature limiting valves are available; see manual.
NOTE:
The TX Series Indirect Water Heater is deemed to be used in a "commercial setting" if at any time the
unit is operated at a temperature over 150°F. Refer to warranty for additional information.
SECTON 2: PRODUCT SELECTION/PERFORMANCE
DHT’s TX Series are indirect water heaters that use part of the home’s boiler heating hot water to heat
domestic water. They offer lower installation and maintenance costs in addition to operational cost
savings due to higher efficiency of the combination system. These units can be coupled with both
condensing and non-condensing type boilers with a wide range of operating temperature ranges to
achieve high efficiency within an optimized space. Stored hot water inside the tank helps to meet the
large instantaneous demand within a short period and provides thermal mass for storage. This helps to
reduce the number of cycles on boiler under the periods of no load to low load conditions and ensures
there is always hot water present.
Domestic cold water enters the unit through the cold water inlet connection toward the bottom of the
tank, and hot water is supplied through the connection on top (see Section 3). If the tank temperature
falls below the set point, boiler water is pumped through the heat exchanger coils, where it heats the
domestic water to recover the water temperature inside the tank to set point. Boiler water enters the
heat exchanger through the inlet connection located on top of the heat exchanger and flows downward
to have counter flow arrangement for effective heat transfer.
The unit is fully constructed of high-quality 444 stainless steel materials; fully automated welding
technology; and passivated preventing corrosion, offering excellent performance and service for many
years. Unlike glass-lined water heaters, an anode is not needed, reducing maintenance costs for the
consumer.
1. The following guidelines apply to residential systems only. For commercial or institutional
installations contact the factory directly for assistance.
2. Determine the quantity of domestic hot water required. Factors to consider:
a. Estimate typical peak hour demand. Determine the general time of day (morning, noon,
evening) when the most hot water is used. Use chart below to determine potential
maximum usage.
HOT
BURN

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 5of 33
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Estimate of Peak Domestic Hot Water Usage
Use
Average Gallons of
Hot Water per Usage
Times Used
During One Hour
Times Used
During One Hour
Showering
20
X
X
=
Bathing
20
X
X
=
Shaving
2
X
X
=
Hands and Face Washing
4
X
X
=
Hair Shampooing
4
X
X
=
Hand Dish Washing
4
X
X
=
Automatic Dish Washing
14
X
X
=
Food Preparation
5
X
X
=
Wringer Clothes Washer
26
X
X
=
Automatic Clothes Washer
32
X
X
=
Total Peak Hour Demand
=
b. Estimate unusual peak draw demand. Whirlpool baths, hot tubs, and multiple head
showers require large quantities of hot water in a short period of time. Contact fixture
manufacturer for quantity of water required. Generally speaking, these circumstances
can be met only with larger storage volumes.
c. Domestic Water Temperature. Most residential usage will be satisfied with 120°F water,
the temperature setting recommended by the Consumer Product Safety Commission.
Some applications, such as laundry machines and dishwashers, may require a higher
temperature.
Ratings can be improved by increasing the TX Series thermostat setting and using a mixing valve to
temper the hot water to the proper temperature. When temperatures greater than 119°F are required,
use a mixing valve at the outlet of the water heater or anti-scald fittings at point of use.
Performance Ratings
Model
TX-40
TX-50
TX-80
TX-110
Capacity(Gallons)
40
50
80
110
Heat Exchanger Surface Area sq.ft.
10.4
12.6
15.0
23.0
Recommended Flow Rate gpm (Boiler Water)
10
10
14
14
Pressure Drop Ft. Hd. (Heat Exchanger)
7.1
7.3
5.0
6.5
First Hr. Ratings gph 90oRise
210
249
336
396
Continuous Flow gph 90oRise
168
197
252
280
First Hr. Ratings gph 77o Rise
238
282
379
443
Continuous Flow gph 77o Rise
197
229
295
327
Boiler Size Btu's Required
120,000
140,000
180,000
199,000
NOTE:Above ratings based on boiler maintaining temperature of 180 degrees Fahrenheit.
SECTON 3: TANK SPECIFICATIONS

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 6of 33
Phone: [phone] Website: www.dhtnet.com
Specifications
Physical Specifications
Model Number
TX-40
TX-50
TX-80
Diameter Of Tank
23”
23”
23”
Volume (Gallons)
40
50
79
Height To
Connection
(Inches)
See above
drawing
(A) Domestic Cold Water Inlet
4.8
4.8
9.0
(B) Control
21.5
24.8
27.0
(C) Recirculation
n/a
n/a
44.7
(D) Boiler Water Inlet (Feed)
38.4
46.3
63.4
(D) Boiler Water Outlet (Return)
38.4
46.3
63.4
(E) Domestic Hot Water Outlet
36.8
44.7
61.8
Overall Tank
38.9
46.8
64.3
Coil Surface (Square Feet)
13.1
15.2
16.8
Net Weight (Lbs.)
86
98
132
Shipping Weight (Lbs.)
94
123
143
Filled Weight (Lbs.)
420
516
792
Connections
Temp. & Press. Relief Valve
¾”
¾”
1”
Domestic Hot Water Outlet
¾”
¾”
1”
Domestic Cold Water Inlet
¾”
¾”
1”
Boiler Water Outlet (Return)
1”
1”
1”
Control
½”
½”
½”
Boiler Water Inlet (Supply)
1”
1”
1”
Recirculation
-
-
¾”

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 7of 33
Phone: [phone] Website: www.dhtnet.com
Specifications
Physical Specifications
Model Number
TX-110
Diameter of Tank
28”
Volume (Gallons)
110
Height To
Connection
(Inches)
See above
drawing
(A) Domestic Cold Water Inlet
11.2”
(B) Boiler Water Outlet (Return)
15.1”
(C) Boiler Water Inlet (Feed)
44.2”
(D) Control
46.1”
(E) Recirculation
52.4”
(F) Domestic Hot Water Outlet
63.4”
(G) Overall Tank
77.0”
Coil Surface (Square Feet)
23.7
Net Weight (Lbs.)
154
Shipping Weight (Lbs.)
176
Filled Weight (Lbs.)
1073
Connections
Temp. & Press. Relief Valve
¾”
Domestic Hot Water Outlet
1 ½”
Domestic Cold Water Inlet
1 ½”
Boiler Water Outlet (Return)
1”
Control
½”
Boiler Water Inlet (Supply)
1”
Recirculation
¾”
NOTE:
Refer to TX Series dimensional drawing available on DHT website for most up-to-date, complete
dimensional details and connection orientations.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 8of 33
Phone: [phone] Website: www.dhtnet.com
TX Series Dimensional Drawing

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 9of 33
Phone: [phone] Website: www.dhtnet.com
SECTON 4: INSTALLATION AND PIPING
SECTON 4.1: LOCATION OF THE TX SERIES WATER HEATER
Locate the heater so that there is easy access to the control, piping, valves, drain, and heater for future
servicing and maintenance. The heater is to be kept in an area where it is not exposed to freezing
temperatures.
Also, the heater must be located in an area where a leak (e.g. from the piping€ or fittings, from any
temperature and relief valve discharge, or from the tank itself), will not cause personal harm or damage
the surrounding area. The tank should be installed in an area with a floor drain or in a pan suitable for
water heaters.
NOTE:
DHT will not be held liable for any damages caused by water leakage.
The floor or area where the tank is installed must be capable of supporting the tank when filled with
water. (Refer to Table at right.)
FOR YOUR SAFETY:
Do not store or use gasoline or other flammable vapors or liquids in the vicinity of this or any other
appliance. Controls on this appliance could ignite vapors causing an explosion.
SECTON 4.2: PIPING INSTALLATION INSTRUCTIONS
1. General
a. All plumbing must be in accordance with the requirements of the authority having
jurisdiction.
b. Use both thread tape and pipe dope on all mechanical connections.
c. Zone valve (if used) and circulator must be sized to provide minimum flow rate specified
in the table to the right, Flow Specifications. Use 1 inch nominal copper tubing between
boiler and heat exchanger. See the tables on Friction Loss. Point of emphasis: using a
zone valve without a full bore may cause high pressure drop, which will adversely affect
performance. Use extreme care when selecting zone valve.
i. All piping must be adequately supported.
ii. Allow for thermal expansion.
iii. Dielectric Unions (recommended) - used to electrically isolate the TX Series tank
from the connected domestic water piping. This helps to minimize the
possibility of corrosion damage.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 10 of 33
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Flow Specifications
Model No.
Recommended
Flow Rate
Heat Exchanger Pressure
Drop (Ft. Hd.)
Boiler Water
Connection Sizes
TX-40
10 GPM
7.1
1”
TX-50
10 GPM
7.3
1”
TX-80
14 GPM
5.0
1”
TX-110
14 GPM
6.5
1”
Friction Loss per 100 Feet of Tubing (psi)
Tubing Type
Flow Rate (gpm)
10 gpm
15 gpm
Type K
3.1 psi
6.5 psi
Type L
2.7 psi
5.7 psi
Type M
2.3 psi
4.7 psi
Friction Loss Allowance for Copper Fittings (feet of straight tubing)
Fitting
Wrought
Cast
90º Elbow
1
4
45º Elbow
1
2
Tee, Run
½
½
Tee, Branch
3
5
90º Bend
2
-
180º Bend
2
-
Gate Valve
-
1

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 11 of 33
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2. Domestic Water
a. Cold Water In. Install brass tee and drain valve (not provided). Install shutoff valve
between water supply and cold water inlet for ease of service as shown in the exhibit
below.
b. Standard Domestic Hot Water Out. A heat trap will improve energy efficiency by
reducing piping heat loss.
Thermostatic Mixing Valve
At times a thermostatic mixing valve may be recommended or required. The thermostatic mixing valve
blends domestic cold water with hot water exiting from the heater, to yield a more constant desired
temperature. Risk of scalding is not eliminated with the use of a thermostatic mixing valve. Refer to
literature provided by valve manufacturers for recommended installation.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 12 of 33
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Expansion Tank
When a back flow device or check valve is installed in the system, a Thermal Expansion Tank designed
for use with potable water will be required. Locate the expansion tank on the domestic cold water line
near the heater between the back flow preventer or check valve and the heater (see piping diagrams).
Refer to the Thermal Expansion Tank manufacturer literature for sizing.
Vacuum Breaker
DHT recommends that a vacuum breaker be installed on the domestic piping to the heater. The vacuum
breaker protects the heater in the event that tank pressure falls below atmospheric pressure.
Temperature & Pressure Relief Valve (T&P)
A T&P is required on all TX Series Indirect Water Heaters. Install a T&P valve (long element type) into the
tapping designated for the T & P.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 13 of 33
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Install temperature and pressure protective equipment required by local codes, but no less than a
combination temperature and pressure relief valve certified as meeting the requirements for Relief
Valve and Automatic Shutoff Devices for Hot Water Systems, ANSI Z21.22, by a nationally recognized
testing laboratory that maintains periodic inspection of listed equipment or materials.
The valve must be oriented, provided with tubing, or otherwise installed so that discharge can exit only
within six (6) inches above, or at any distance below, the structural floor and cannot contact any
electrical part. The valve must be piped to an area where discharge will not cause personal injury or
damage the surrounding area.
WARNING: TEMPERATURE & PRESSURE RELIEF VALVE
Install a T&P with a rated capacity that is equal to or greater than the output of the energy
source.
Removal of the T&P, or failure to replace temperature-pressure relief valve, will release the
manufacturer from any claim which might result from excessive temperatures and pressures.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 14 of 33
Phone: [phone] Website: www.dhtnet.com
SECTON 4.3: TANK INSTALLATION
SINGLE UNIT INSTALLATION

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 15 of 33
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MULTIPLE UNITS INSTALLATION
NOTES:
These are typical installation piping drawings. Consult local codes and authorities.
Refer to dimensional drawing for actual size and location dimensions of piping and other
connections since they vary depending upon unit model.
Relief valve shall be installed to safe drain according to appropriate plumbing codes.
Piping connections to the unit shall be provided with unions or flanges maintaining enough
clearances for service. Dielectric fittings are suggested to make connections between dissimilar
metals to prevent galvanic corrosion.
A check valve may be utilized in place of backflow preventer if permitted by local codes.
Piping installation components are supplied by others in the field.
Expansion tank shall be installed whenever a backflow preventer or check valve is present in the
system. Locate the Thermal Expansion Tank on the domestic cold water line between the heater and
backflow preventer or no return valve.
Use balancing valves to balance the flow through all units if the piping arrangement is not reverse
return.
Recirculation line connections available only for TX-80 and TX-110 unit models.
Multi Units Installation

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 16 of 33
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SECTON 4.4: PIPING INSTALLATION INSTRUCTIONS FOR USE WITH A STEAM
BOILER
INSTALLATION:
Install valves B and C a minimum of 6” below water line G. Keep valves as close to the boiler as possible.
Install boiler drains D and E as close as possible to valves B and C.
FILL AND PURGE:
1. Close valves B and C.
2. Attach a hose from an independent water source to boiler drain E.
3. Attach a hose to boiler drain D leaving open end of hose in an empty bucket or basin.
4. Open boiler drains E and D and allow water to fill coil of tank. Continue to allow water to flow
until the flow is free of air (smooth, non-sputtering flow).
5. Close drain D and then boiler drain E.
6. Open valves B and C and observe boiler water level at the gauge glass, making sure that is
remains at its original level.
7. Fill the potable water side of the tank and purge air from the tank by opening a hot water
faucet.
8. When the power is switched on, the tank aquastat will turn on pump F, and when the
temperature of the boiler falls below the set-point, the boiler will fire.
A. Flow control/Check valve
B. Ball or gate valve
C. Ball or gate valve
D. Boiler drain
E. Boiler drain
F. Permanently lubricated pump
G. Water level
H. Tank Aquastat
I. Boiler Aquastat
J. Strainer

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 17 of 33
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NOTE:
When installing the TX Series Indirect Water Heater with a steam boiler, the water flow (direction) is
reversed through the tank coil (heat exchanger). The boiler water enters at the bottom of the coil and
exits from the top of the coil. At no time should live steam be used in the tank coil (heat exchanger).
SECTON 5: ELECTRICAL AND CONTROLS WIRING
NOTE:
All wiring must be done in accordance with national, state, and local codes. Adhere to the National
Electric Code - ANSI/NFPA 70-1990 in the absence of any other codes.
FOR YOUR SAFETY:
Power must be shut off before installing or servicing the water heater. A separate shut-off switch should
be installed to support future servicing or an emergency shut down. The entire heating system should
have its own designated electrical circuit.
The TX Series water heater operates in much the same way as an additional heating zone, either utilizing
the same circulator as household heating or its own circulator. The water heater temperature is
maintained by the use of an immersion type aquastat. The aquastat is installed into the immersion well
on the heater and secured by tightening the set screw or clamp.
The aquastat operates in much the same way as a thermostat. When the water temperature falls below
desired set point inside the tank, the set of contacts make (close) and when the temperature rises above
the set point inside the tank, the contacts break (open).
The aquastat should be tied into the boiler system and controls. When the tank calls for heat the
aquastat contacts close and signal the boiler controls, allowing the boiler to maintain temperature and
proper operation of the tank circulator.
DHT recommends the use of a priority control to help the boiler maintain desired temperature and
satisfy the tank's BTU requirements (domestic water temperature).
The TX Series water heater recovery ratings are based on the boiler's ability to maintain 180 degrees
Fahrenheit. It is important that the installer, plumber, or heating technician responsible for installing the
heater make certain that the boiler capacity (BTU) is adequate to satisfy the heater's BTU requirements.

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 18 of 33
Phone: [phone] Website: www.dhtnet.com
:
Water temperatures over 125°F can cause severe burns instantly or
death from scalds.
Children, disabled, and elderly are at the highest risk of being
scalded.
See instruction manual before setting temperature at water
heater.
Feel water before bathing or showering.
Temperature limiting valves are available; see manual.
TANKLESS COIL BOILER APPLICATION
10
Operation: When any thermostat calls for heat, the boiler is given a signal to start. The appropriate
circulator is energized only when the boiler temperature is above the set low limit.
HOT
BURN

TX Series Installation, Operation, and Maintenance Manual
Diversified Heat Transfer, Inc. 439 Main Road, Route 202 Towaco, New Jersey 07082 Page 19 of 33
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Priority Operation: When zone 6 is switched to the priority setting and is actuated, all other zones will
stop operation until zone 6 is satisfied. When zone 6 is not switched to priority, all zones will operate
independently.
Jumper Placement: REMOVE the jumper between terminals ZC and ZR. Connect terminal ZC to ZC
terminal on the aquastat control. Connect terminal ZR to ZR terminal on the aquastat control. Confirm
polarity is consistent between boiler aquastat and switching relay.
Power Input: Connect 120 volt as power input to terminals N and H. Neutral wire to terminal N. Hot
wire to terminal H.
NOTE:
Aquastat: The water heater aquastat has operating set point range from 100°F to 240°F. The differential
is variable from 5°F to 30°F. It is set at 120°F set point with 5°F differential.
COLD START BOILER APPLICATION

TX Series Installation, Operation, and Maintenance Manual
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Operation: When any thermostat calls for heat, the appropriate circulator is energized, and the isolated
end switch (X and X) will start the boiler.
Priority Operation: When zone 6 is switched to the priority setting and is actuated, all other zones will
stop operation until zone 6 is satisfied. When zone 6 is not switched to priority, all zones will operate
independently.
Jumper Placement: The jumper should be placed between terminals ZC and ZR. Connect the isolated
end switch to the aquastat control on the boiler.
Power Input: Connect 120 volt as power input to terminals N and H. Neutral wire to terminal N. Hot
wire to terminal H.