RECO HX2 Series Installation guide

Installation, Operation,
and Maintenance Manual
INSTALLATION,OPERATION,
AND MAINTENANCE MANUAL

TABLE OF CONTENTS
Introduction -
1.1 Overview of the HX2........................................................................................................................ 1-1
1.2 Sales and Service Support................................................................................................................ 1-2
1.3 Key Features and Benefits of the HX2 ................................................................................................ 1-2
1.4 Materials of Construction.................................................................................................................. 1-2
1.5 Flow, Pressure, and Temperature Ratings .......................................................................................... 1-2
1.6 Recommended Spare Parts .............................................................................................................. 1-3
1.7 HX2 Rating Charts........................................................................................................................... 1-3
1.8 HX2 Configuration and Ordering Code................................................................................................ 1-6
Installation -
2.1 Shipment and Storage ..................................................................................................................... 2-1
2.2 General Installation Instructions and Guidelines .................................................................................. 2-1
2.3 Major Components of the HX2 .......................................................................................................... 2-2
2.4 Factory Pre-Sets ............................................................................................................................. 2-3
2.5 General Arrangement Dimensions and Weights –Vertical Units............................................................. 2-4
2.6 General Arrangement Dimensions and Weights –Horizontal Units ......................................................... 2-5
Operation -
3.1 Operating Instructions and Guidelines–Start Up ................................................................................. 3-1
3.2 Operating Instructions and Guidelines –Shut Down............................................................................. 3-2
3.3 System Wiring Diagram ................................................................................................................... 3-3
Maintenance
4.1 HX2 Maintenance Schedule............................................................................................................... 4-1
4.2 Troubleshooting .............................................................................................................................. 4-1
4.3 HX2 Tube Bundle Maintenance .......................................................................................................... 4-5
4.4 Flange Bolt Tightening Sequence and Torque Values............................................................................ 4-7
4.5 Circulator Pump Maintenance............................................................................................................ 4-7
4.6 Strainer Maintenance....................................................................................................................... 4-8
4.7 Control Valve Maintenance ............................................................................................................... 4-9
Appendix 1 –The Control Master®Control Panel
A.1 General Operation ........................................................................................................................... A-1
A.2 Start Up Procedures ........................................................................................................................ A-2
A.3 Adjusting the Set Points ................................................................................................................... A-4
A.4 Adjusting the Alarm Settings ............................................................................................................ A-5
A.5 Alarm Menu.................................................................................................................................... A-6
A.6 Fault Detection ............................................................................................................................... A-7
A.7 Panel Box Layout and Component Listing ........................................................................................... A-8
A.8 Panel Box Controller Connections ...................................................................................................... A-9
A.9 Control Panel Display Listings ......................................................................................................... A-10

1 - 1
THE HX2 SERIES
SEMI-INSTANTANEOUS WATER HEATERS
INSTALLATION,OPERATION,AND MAINTENANCE MANUAL
INTRODUCTION
This Installation, Operation, and Maintenance (IOM) manual is current as of the date issued,
and RECO USA reserves the right to update, modify, amend, or change the information
contained herein at any time without prior notice and without obligation to notify owners of
this product of such changes.
All installation, operation, and maintenance should only be attempted by authorized personnel
trained to do so, and any personnel attempting these tasks should be completely familiar with
the contents of this IOM manual before attempting to do so.
1.1 HX2 Overview
The HX2 is RECO USA’s next generation of compact, semi-instantaneous water heaters
using available steam as the heating medium. Designed to the guidelines of TEMA,
BOCA and IAPMO, these heaters can heat up to 150 GPM from 40 °F to 140 °F as
standard, with higher capacities possible.
At the heart of the control system is the
Control Master®panel with a digital PAC
controller. The Control Master has an easy-
to-navigate LCD panel for local monitoring
and set point adjustment. It accepts remote
set point changes and can re-transmit water
temperature via standard Modbusor
BACnetcommunications protocols.
An electrically operated, fast-acting V-ball
control valve is used to modulate the flow of
the heating fluid. It has a 100:1
rangeability which gives excellent control at
all flow rates. Capacitors integrated into the
actuator housing close the valve in the
event of loss of main power. Soft valve
seats provide tight valve shut-off and
prevent temperature rises at low load due
to valve seat leakage.
Fig. 1 –A horizontal HX2 unit (not all piping
shown or insulation jacket shown)

SECTION 1-INTRODUCTION HX2 SERIES
1 - 2
1.2 Sales and Service Support
Key contacts at RECO USA for any quotation, sales, expediting, literature requests,
shipping, or accounting issues can be reached at our main plant is located at 1839
Dunbar Road, Cayce, SC 29033.
Our main phone numbers are:
•Main office .................... [phone]
•Main fax ....................... [phone]
To order replacement parts, contact RECO USA or your local authorized RECO USA
representative.
1.3 Key Features and Benefits of the HX2
•The HX2 safety system includes a pressure/temperature (P/T) relief valve, solenoid-
operated, fail-open dump valve, and an automatic fail-closed steam inlet control
valve.
•Lightweight, compact design fits through standard doorways and freight elevators.
•High accuracy temperature control of ±4 °F achieved.
•Continuous forced re-circulation eliminates temperature stratification and ensures a
uniform temperature distribution across all temperature sensors while also reducing
scaling and sediment build-up on the tube bundles in the process.
•ASME constructed and stamped tank assures safe operation to 150 PSIG.
•All wetted parts on the heated side are lead-free and comply with NSF Standard 61
and the requirements of the U.S. Safe Drinking Water Act.
•Support stand can comply with International Building Code (IBC) guidelines for
seismic requirements.
1.4 Materials of Construction
The standard HX2 tank and couplings are 316L stainless steel passivated to ASTM A380
and A967. Piping is carbon steel, welded or threaded as appropriate. All units come with
a flexible insulation jacket conforming to ASHRAE Std. 90.1, and the support stand and
heating bundle head are powder coated for added durability.
1.5 Flow, Pressure, and Temperature Ratings
•Heated water recovery rate .............................. 5 to 150 GPM
•Steam supply pressure..................................... Up to 100 PSIG
•Cold water inlet pressure.................................. Up to150 PSIG
•Heated water outlet temperature....................... Up to 210 °F
•Design rating .................................................. ASME Boiler and Pressure Vessel
Code “U” stamped

SECTION 1-INTRODUCTION HX2 SERIES
1 - 3
1.6 Recommended Spare Parts
The table below shows the main spare parts available with the HX2, along with a
recommendation for parts to be kept on hand to support the unit(s) in operation.
TABLE 1-1 RECOMMENDED SPARE PARTS PER UNIT
Operation
Gasket Kit
Pressure
Gage Kit
P/T Relief
Valve
RTD
Assembly
High Limit
Thermostat
Circulator
Pump Kit
Steam Trap
& Strainer Kit
Tube Bundle
Solenoid
Valve
Control Valve
Kit
Insulation
Jacket
Control Panel
At Start Up
⚫
⚫
5 Yr. Operation
⚫
⚫
⚫
⚫
⚫
⚫
⚫
⚫
10 Yr. Operation
⚫
⚫
⚫
⚫
⚫
⚫
⚫
⚫
⚫
⚫
⚫
⚫
1.7 HX2 Rating Charts
To select an HX2 the steam pressure (PSIG) available, amount of water (GPM) to be
heated, and amount of heating (°F) to be done must be known. Heating is commonly
specified in increments of 80 °F (40 °F to 120 °F) or 100 °F (40 °F to 140 °F).
The first step is to locate the correct chart from the four that follow. Next locate the
appropriate Steam Supply Pressure available (PSIG) along the X-axis, and the amount of
water to be heated (GPM) along the Y-axis. Where the two intersect, find the rating
curve corresponding to those conditions. If this intersection lies between two rating
curves, choose the larger unit (higher curve).
Notes:
1. For copper-nickel tubes, de-rate the copper tube ratings shown by 20%.
2. The ratings curves shown assume a tube bundle fouling factor of 0.00025 (hr. x ft2
x °F / BTU).
3. For applications with water as the heating source, contact RECO USA Sales
Department.

SECTION 1-INTRODUCTION HX2 SERIES
1 - 4
1.7a Rating Charts for 40 °F to 120 °F Heating
40 °F to 120 °F Heating –Single Wall, ½” OD Copper Tubes
40 °F to 120 °F Heating –Double Wall, ¾” OD Copper Tubes
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
010 20 30 40 50 60 70 80 90 100
Water to be Heated - GPM
Steam Supply Pressure -PSIG
40 F to 120 F - Single Wall Copper Tubes
12030
10030
08030
06030
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
010 20 30 40 50 60 70 80 90 100
Water to be Heated -GPM
Steam Supply Pressure - PSIG
40 °F to 120°F - Double Wall Copper Tubes
12036
12030
10036
10030
08036
08030
06036
06030

SECTION 1-INTRODUCTION HX2 SERIES
1 - 5
1.7 Rating Charts for 100 °F Heating
40 °F to 140 °F Heating –Single Wall, ½” OD Copper Tubes
40 °F to 140 °F Heating –Double Wall, ¾” OD Copper Tubes
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
010 20 30 40 50 60 70 80 90 100
Warer to be Heaterd -GPM
Steam Supply Pressure - PSIG
40 F to 140 F - Single Wall Copper Tubes
12030
10030
08036 08030
06036
06030
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
010 20 30 40 50 60 70 80 90 100
Water to be Heated -GPM
Steam Supply Pressure - PSIG
40 °F to 140 °F - Double Wall Copper Tubes
12036
12030
10036
10030
08036
08030
06036
06030

SECTION 1-INTRODUCTION HX2 SERIES
1 - 6
1.8 HX2 Configuration and Ordering Code
The following Configuration and Ordering Code defines the HX2 and can be found on the
unit nameplate. When inquiring about a HX2 this code must be used. Doing so enables
us to handle requests quicker and assure the correct unit is being discussed.
1.8a Sample Selection:
The selected unit is a RECO USA HX2 series water heater model HX2-H-0836-SS-CU-
DW-Mhorizontal water heater with 8” diameter x 36” long heating element, 316L
stainless steel tank, ¾” copper double-wall tubes, and standard Modbus® communication
interface with the building automation system.
- - - - CU - -
Heater Series BAS Interface
HX2 Series Water Heater
⚫M - Modbus
A - BACnet IP
B - BACnet MS/TP
Orientation
H - Horizontal
V- Vertical Heater Tube Style
⚫
DW - Double wall - ¾"
SW - Single wall -½"
Heater Size (Nominal)
06030 - 6" D x 30" L
06036 - 6" D x 36" L Tube Material
⚫CU - Copper
08030 - 8" D x 30" L XX - Other
08036 - 8" D x 36" L
10030 - 10" D x 30" L Tank/Shell Material
10036 - 10" D x 36" L ⚫SS - 316L stainless steel
CN- Copper-Nickel
12030 - 12" D x 30" L XX - Other
12036 - 12" D x 36" L
⚫Denotes standard configuration
M
08036
DW
HX2
H
SS

2 - 1
THE HX2 SERIES
SEMI-INSTANTANEOUS WATER HEATERS
INSTALLATION
The following guidelines must be followed when installing a HX2 series water heater.
Failure to do so can result in faulty performance, field service / support charges, and/or
voiding of the warranty. Installation, operation, and/or maintenance should only be
performed by trained personnel knowledgeable in proper plumbing and electrical practices,
and in particular should be thoroughly trained in working with high pressure steam systems.
2.1 Shipment and Storage
All products are assumed to be installed and operated soon after receipt. RECO USA
does not include any special preservation for long term storage, and assumes no
responsibility for storage deterioration after shipment unless explicitly agreed to in
writing beforehand. All units must only be lifted by the lifting lug(s) provided, as
failure to do so could result in damage to the unit.
After the unit has been uncrated, it should be carefully examined for any damage that
may have occurred in transit. If any damage is found and a shipping claim of damage
is being made, immediately contact RECO USA or your local authorized sales, as well
as the common carrier who delivered the unit(s).
2.2 General Installation Instructions and Guidelines
2.2.1 The HX2 is designed for indoor use only, unless specified otherwise. Install the
unit so there is adequate room around the unit for servicing. Provide clear access
(see Figures 1.7 and 1.8) to permit tube bundle removal.
2.2.2 The unit should be level to permit proper drainage and must be anchored securely
to the floor. It should be on a level surface with no more than 0.5slope and
capable of supporting the total weight of the unit when filled to capacity.
2.3.3 All steam, water, and condensate lines should be installed in accordance
with good engineering practices. Note that the ASME code requires that no
reduction in pipe size, and no valves or other restrictions may be introduced
in the piping from the relief valve.
2.2.4 After mounting the unit in place, connect the cold-water source to the unit’s cold-
water inlet, and then the hot water discharge from the unit to the building hot
water feed line. The locations of these are indicated on the General Arrangement
drawings in Figures 1.7 and 1.8.
2.2.5 Next connect the steam outlet trap and strainer (supplied loose) to the unit, and
connect this line to the steam condensate return line.

SECTION 2-INSTALLATION HX2 SERIES
2 - 2
2.2.6 Pipe the relief valve, tank drain, and solenoid dump valve separately to a suitable floor
drain. Do not install a valve in relief valve or solenoid valve line, as that would defeat
the purpose of these drain lines.
2.2.7 Complete the installation by making the appropriate electrical connections to the main
control panel.
2.2.8 A manual shut off valve of the same size as the inlet water line should be installed
upstream of the cold-water supply to the unit, and kept in the closed position until the
installation is complete. A shut off valve of the same size as the hot water discharge line
should also be installed at the unit’s hot water discharge. Together, these two valves will
isolate the heated water side of the unit.
2.2.9 A manual shut off valve of the same size as the steam inlet line should be installed
upstream of the steam supply to the unit.
2.2.10 The condensate return line should have a shut off valve of the same size as the line
installed downstream of the unit to isolate it from the system. This valve will also prevent
backflow of steam if the line is disconnected at the unit’s hot water discharge.
2.2.11 All piping is pressure tested at the factory for leaks prior to shipment. However, piping
connections can loosen during transit, and installation, resulting in leaking connections,
damaged threads, etc. Once installed and started, all piping should be inspected again,
and any leaks or damage corrected at the time of installation.
2.2.12 An inlet steam strainer and steam trap immediately upstream of the inlet control valve
(not provided by RECO USA) is necessary for optimal system performance. A condensate
strainer and steam trap are provided loose as standard, with mounting and connection
to be done in the field by others.
2.2.13 A suitable means, such as a gravity drain or condensate pump system, must be provided
to remove condensate from the unit and otherwise prevent condensate from collecting
and blocking its ability to freely flow away from the unit.
2.3 Major Components of the HX2
A general listing of the major, external components of an HX2, and their function, are as
follows:
2.3.1 The solenoid valve is an electrically actuated, normally closed valve that opens to
relieve tank pressure once a pre-set high temperature limit is exceeded. It should be
independently piped to a suitable gravity drain using a line size of the same size as
the solenoid valve discharge.
2.3.2 The resistance temperature detector (RTD) is a temperature probe immersed in the
tank flow stream near the discharge nozzle. Under normal operation it is a self-
contained device not requiring routine maintenance.
2.3.3 The high-limit thermostat is a primary safety feature that upon reaching a pre-set
high temperature limit, interrupts power to the control valve, causing it to close, and
energizes the solenoid valve to open.
2.3.4 The pressure/temperature (P/T) relief valve is a secondary mechanical safety device
used to protect against over-pressure or over-temperature conditions within the unit
tank. It should be independently piped to a suitable gravity drain using a line size of
the same size as the relief valve discharge.
2.3.5 The circulator pump consists of a pump/motor assembly with companion flanges. It
provides continuous circulation throughout the tank, which ensures a uniform
temperature distribution across all temperature sensors.

SECTION 2-INSTALLATION HX2 SERIES
2 - 3
2.3.6 An electrically operated, fast-acting V-ball control valve is used to modulate flow of
heating medium to the unit. It has a 100:1 rangeability which gives excellent control
at all flow rates. Capacitors integrated into the actuator housing close the valve in
the event of loss of power.
2.3.7 The steam trap and strainer are a float and thermostatic (f & t) type steam trap and
“Y” type strainer. These components are supplied loose for connection at the steam
(condensate) outlet of the heating tube bundle.
2.3.8 The insulation jacket is a flexible, Velcro-attached design specific to the unit it
insulates. All cut outs and openings for piping and instrumentation are provided for
easy installation without the need for field modification.
2.3.9 The tube bundle is provided pre-assembled into the heating tank, with all piping and
controls installed and tested, ready for start-up and operation.
2.3.10 The Control Master control panel is a complete, pre-assembled and pre-wired unit
with a programmable automation controller (PAC) and easy to navigate LCD panel for
local monitoring and set point adjustment.
2.4 Factory Pre-Sets
All temperature settings for the unit are factory set for the specified outlet temperature
requirements. This is typically 120 F or 140 F.
2.4.1 The temperature pre-sets start with the RTD sensor and PID control loop tied to the
control panel PAC. It is set to the specified outlet water temperature, and modulates
the control valve position to maintain the inflow of steam corresponding to the demand
for hot water. Upon reaching the desired water outlet temperature, the control valve
will back off to the point it may fully close. Outlet water temperature is controlled to
+/- 4 F.
2.4.2 The high temperature alarm is set to 10 F above the outlet temperature setting. Upon
reaching this setting the control panel LCD display will blink and send an alarm signal
to the BAS (if so wired). Upon returning below this high temperature setting, the
system will automatically come out of alarm mode and reset itself without the need for
a manual reset.
2.4.3 In addition to the RTD sensor and PID control loop, a separate high temperature limit
switch is provided. This is pre-set to 10 F above the high temperature alarm setting
(which is 20 F above the outlet water temperature setting). In the event the high
temperature limit switch is tripped, it will cut power to the control panel. This will de-
energize the steam inlet control valve, causing it to fail closed and cut off any further
supply of steam to the unit, and energize the tank-mounted solenoid valve, causing it
to open and relive any pressure in the tank.
2.4.4 As a third safety feature, a factory pre-set pressure / temperature relief valve mounted
near the tank outlet will open upon reaching its high pressure or temperature setting,
relieving the contents of the tank until the internal pressure in the tank falls below the
valve settings. These settings are typically 150 PSIG and 210 F, respectively.

SECTION 2-INSTALLATION HX2 SERIES
2 - 4
2.5General Arrangement Dimensions and Weights –Vertical Units
TABLE 2-1 VERTICAL UNIT DIMENSIONS
Basic Size
A
B
E
H
I
L
R
S
T
V
W
Wt. (lbs.)
06030 / 06036
2”
1 ½"
46.75
95.0
34.25
32
¾FNPT
24.0
17.75
1” FNPT / 1.25” FNPT
33.0
930 / 950
08030 / 08036
3”
2 ½"
46.75
97.0
34.25
38
1.5 FNPT
24.0
17.75
1.5” FNPT / 2” FNPT
35.0
1,125 / 1,155
10030 / 10036
4”
3"
46.75
99.0
33.75
49
1.5 FNPT
24.0
17.75
2.5” 150 Lb. RFSO
37.0
1,380 / 1,420
12030 / 12036
4”
3"
46.75
100.0
33.75
51
1.5 FNPT
24.0
17.75
3” 150 Lb. RFSO
39.0
1,655 / 1,705
Notes:
1. Dimensions “A” and “B” are nominal sizes for ANSI 150 lb. raised face, slip on (RFSO) flange.
2. All dimensions in inches, unless noted otherwise.
3. Weights shown are net empty weight for a standard HX2 unit. Crating or shipping materials not included.

SECTION 2-INSTALLATION HX2 SERIES
2 - 5
2.6 General Arrangement Dimensions and Weights –Horizontal Units
TABLE 2-1 HORIZONTAL UNIT DIMENSIONS
Basic Size
A
B
E
H
I
K
L
R
S
T
U
V
W
Wt. (lbs.)
06030 / 06036
2”
1 ½"
23.75
95.0
34.25
37.75
71.75
¾FNPT
24
39
41
1” / 1.25” FNPT
33
985 / 1,005
08030 / 08036
3”
2 ½"
23.75
97.0
34.25
38.75
73.5
1.5 FNPT
24
39
41
1.5” / 2” FNPT
35
1,180 / 1,210
10030 / 10036
4”
3"
23.75
99.0
33.75
39.75
74
1.5 FNPT
24
39
41
2.5” 150 Lb. RFSO
37
1,435 / 1,475
12030 / 12036
4”
3"
23.75
100.0
33.75
40.75
77
1.5 FNPT
24
39
41
3” 150 Lb. RFSO
39
1,710 / 1,765
Notes:
1. Dimensions “A” and “B” are nominal sizes for ANSI 150 lb. raised face, slip on (RFSO) flanges.
2. All dimensions in inches, unless noted otherwise.
3. Weights shown are net weight for a standard HX2 unit. Crating or shipping materials not included.
4. Allow “L” dimension plus 6 inches for tube bundle removal clearance.

SECTION 2-INSTALLATION HX2 SERIES
2 - 6
THIS PAGE LEFT INTENTIONALLY BLANK

3 - 1
THE HX2 SERIES
SEMI-INSTANTANEOUS WATER HEATERS
OPERATION
3.1 Operating Instructions and Guidelines –Start Up
Before starting, read this HX2 Installation, Operation, and Maintenance Manual (IOM) in its
entirety prior to proceeding. The separate section on the Control Master operation
(Appendix A) contains important information on pump on/off, and control valve open/close
instructions that should be understood before starting the unit up.
3.1.2 Begin with all assuring all steam, condensate, and water valves closed.
3.1.3 Slowly open the inlet and outlet isolation valves at the pump on the circulator line.
3.1.4 Open the cold-water inlet valve and fill unit with cold water. The tank can be vented
by lifting the bypass lever on relief valve to allow trapped air to escape. Allow the
relief valve lever to return to its original closed position once all traces of air have
been vented from the unit. Leave the cold-water valve open.
3.1.5 Activate (Enable) the circulator pump at the control panel LCD display. Never operate
the pump without the unit being filled with water and all isolation valves open, or damage
to the pump will result from dry running.
3.1.6 Gradually open the control valve to allow steam to enter the tube bundle. Monitor the
tank temperature until the desired temperature is reached. If the temperature regulator
shuts off before the desired temperature is reached, or if significant over-shoot occurs,
adjustment of the temperature settings may be required.
3.1.7 After any control valve adjustments have been made, and the desired water
temperature has been reached, open the valves on the hot water discharge and
building recirculation line.
3.1.8 Check for any leaks, as tightening of gasketed joints may be required after unit has
been heated.
3.1.9 Never allow the unit to operate beyond its design conditions (see Section 1.5).
3.1.10 Never break any joint, gasketed surfaces, or threaded connections while the unit is
in operation. Instead, the unit must be isolated and de-energized, with adequate
time given for it to cool (see Shut Down instructions, Section 3.2).

IOM SECTION 3- OPERATION HX2 SERIES
3 - 2
3.2 Operating Instructions and Guidelines –Shut Down
Before shutting the unit down, assure that hot water demand for the unit is not needed.
The operator should also re-read this HX2 Installation, Operation, and Maintenance Manual
(IOM) in its entirety prior to proceeding.
To shut the unit down, follow the sequence as listed:
3.2.1 Close the inlet control valve to cut off incoming live steam to the unit.
3.2.2 Close the hot water discharge valve at the tank outlet.
3.2.3 Close the building recirculation valve, isolating the unit from the building steam
line.
3.2.4 Close the water inlet valve to cut off incoming cold water to the unit.
3.2.5 Turn off all electrical power to the unit control panel.
3.2.7 With the unit now isolated by the valving, and de-energized electrically, lift the
release lever on the tank relief valve to evacuate hot water in the tank until the
tank interior is brought to atmospheric pressure.
3.2.8 Open the tank drain valve to drain the remaining water from the tank.

IOM SECTION 3- OPERATION HX2 SERIES
3 - 3
3.3 System Wiring Diagram - Sizes 0630 and 0636

IOM SECTION 3- OPERATION HX2 SERIES
3 - 4
3.4 System Wiring Diagram - Sizes 0830 Through 1236

4 - 1
THE HX2 SERIES
SEMI-INSTANTANEOUS WATER HEATERS
MAINTENANCE
4.1 HX2 Series Maintenance Schedule
Even under the best of conditions, some regular maintenance on the HX2 is needed. The
table below is a general guide as to how often this should be done.
TABLE 4-1 RECOMMENDED INSPECTION INTERVALS
Item
At Start
Up
Weekly
Monthly
Quarterly
Annually
Bi-
annually
Circulator Pump
⚫
⚫
Control Panel
⚫
⚫
Control Valve
⚫
⚫
Drain Valve
⚫
⚫
Pressure Gauge
⚫
⚫
Heat Exchanger Gaskets
⚫
⚫
Heat Exchanger Tube Bundle
⚫
⚫
Manual Shut Off Valves
⚫
⚫
Piping Connections
⚫
⚫
Pressure / Temperature Relief Valve
⚫
⚫
Solenoid Valve
⚫
⚫
Steam Trap
⚫
⚫
Support Stand
⚫
Strainer
⚫
⚫
Vacuum Breaker
⚫
⚫
4.2 Troubleshooting
The table below is a quick summary of common problems encountered, and their most
likely causes, along with a recommendation for how to correct them. These are by not
intended to be an all-inclusive, definitive answer to every field issue that can occur, but
rather a reasonable approach to common problems considering the highest likelihood of
root cause, and how we would suggest addressing those problems based on our own
experience.

IOM SECTION 4- MAINTENANCE HX2 SERIES
4 - 4
TABLE 4-2 TROUBLESHOOTING FIELD GUIDE
Problem
Likely Cause and Suggested Remedy
1
2
3
4
5
6
7
8
9
10
Unit fails to reach required outlet water temperature
⚫
⚫
⚫
⚫
⚫
⚫
Outlet water temperature too high
⚫
⚫
⚫
⚫
Outlet water temperature unsteady
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Tube bundle leaking
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Outlet water temperature decreasing over time
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Relief valve popping
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Control valve cycling, non-steady operation
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Steam discharging into condensate line
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4.2a Troubleshooting Issues and Remedies
1 –The RTD sensor is not reading the temperature correctly.
Remedy - Check the water temperature with a temperature gauge known to be
accurate. Replace the RTD if it is found to be faulty.
2 –The inlet steam is not at the specified temperature, pressure, or flow rate.
Remedy - Check the inlet steam pressure with a suitable pressure gauge with the
control valve fully open. If the reading is low, adjust the inlet pressure to the
required inlet pressure. If this initial reading is correct, the pressure gauge reading
should reach the design pressure for the steam in the heating coil as the water
temperature in the tank approaches shut off.
3 –The Condensate return piping has not been installed properly, and the condensate
is not able to freely drain.
Remedy - Re-route the condensate return line and assure there are no restrictions
in that line and that the condensate is either being pumped away or free to gravity
drain.
4 –The outlet steam trap or strainer basket are clogged.
Remedy - Check both for fouling and clean as necessary. Follow the procedures
given in Section 4.6 for further details on how to do this.
5 –The steam control valve or not opening or closing properly.
Remedy - Follow the procedures given in Section 4.7 for further details on how to
do this.
6 –The high temperature sensor is not set correctly or is not functioning properly.
Remedy - Check the setting on the unit and re-set as necessary. If this does not
work the sensor will need to be replaced.
7 –There is a leak with one or more tubes in the tube bundle, either directly in a tube
or at the tube-to-tubesheet interface, causing tank water or steam condensate to
leak out the tube bundle weep hole area.
Remedy –A tube has worn through, either through erosive or corrosive wear, or