HTP UFT-175W User manual

272 Duchaine Blvd. New Bedford, MA 02745 www.htproducts.com
LP-542 REV. 6.2.16
Universal Fire Tube Boiler
Wall Mount
INSTALLATION
START-UP
MAINTENANCE
PARTS
WARRANTY
Models
UFT-80W / 100W / 120W / 140W / 175W / 199W
Heat Exchanger Bears the ASME “H” Stamp
NOTICE: HTP reserves the right to make product changes or updates without notice and will not be held liable for typographical errors
in literature.
NOTE TO CONSUMER: PLEASE KEEP ALL INSTRUCTIONS FOR FUTURE REFERENCE.
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. DO NOT STORE GASOLINE OR OTHER FLAMMABLE VAPORS
AND LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER BOILER.
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 a neighbor’s phone. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier, call the fire department. Installation and service must be provided by a qualified installer,
service agency, or the gas supplier.

2
LP-542 REV. 6.2.16
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk
levels, or to important product information.
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property
damage.
NOTICE
SAFETY INSTRUCTIONS
NOTICE is used to address practices not related to personal
injury.
SAFETY INSTRUCTIONS (or equivalent) signs indicate specific safety
related instructions or procedures.
NOTE: Contains additional information important to a procedure.

3
LP-542 REV. 6.2.16
FOREWORD
This manual is intended to be used in conjunction with other
literature provided with the boiler. This includes all related control
information. It is important that this manual, all other documents
included with this system, and additional publications including
the National Fuel Gas Code, ANSI Z223.1-2002, be reviewed in
their entirety before beginning any work.
Installation should be made in accordance with the regulations of
the Authority Having Jurisdiction, local code authorities, and utility
companies which pertain to this type of water heating equipment.
Authority Having Jurisdiction (AHJ) –The Authority Having
Jurisdiction may be a federal, state, local government, or
individual such as a fire chief, fire marshal, chief of a fire
prevention bureau, labor department or health department,
building official or electrical inspector, or others having statutory
authority. In some circumstances, the property owner or his/her
agent assumes the role, and at government installations, the
commanding officer or departmental official may be the AHJ.
NOTE: HTP, Inc. reserves the right to modify product technical
specifications and components without prior notice.
FOR THE INSTALLER
This boiler must be installed by qualified and licensed personnel. The installer should be guided by the instructions furnished with the
boiler, and with local codes and utility company requirements. In the absence of local codes, preference should be given to the National
Fuel Gas Code, ANSI Z223.1-2002.
INSTALLATIONS MUST COMPLY WITH:
Authority Having Jurisdiction, local, state, provincial, and national codes, laws, regulations and ordinances.
The latest version of the National Fuel Gas Code, ANSI Z223.1, from American Gas Association Laboratories, 8501 East Pleasant
Valley Road, Cleveland, OH 44131.
In Canada –CGA No. B149 (latest version), from Canadian Gas Association Laboratories, 55 Scarsdale Road, Don Mills, Ontario,
Canada M3B 2R3. Also, Canadian Electrical Code C 22.1, from Canadian Standards Association, 5060 Spectrum Way, Suite 100,
Mississauga, Ontario, Canada L4W 5N6.
Code for the installation of Heat Producing Appliances (latest version), from American Insurance Association, 85 John Street, New
York, NY 11038.
The latest version of the National Electrical Code, NFPA No. 70.
NOTE: The gas manifold and controls met safe lighting and other performance criteria when the boiler underwent tests specified in
ANSI Z21.13 –latest edition.
The hydronic supply and return connections of these products are for installation in closed loop systems ONLY! Use of this
product in any manner other than described in this manual may result in premature product failure, substantial property damage, severe
personal injury, or death. Damage or failure of this product (or the system in which it is installed) due to unauthorized use IS NOT
COVERED BY WARRANTY.
This manual must only be used by a qualified heating
installer/service technician. Read all instructions in this manual
before installing. Perform steps in the order given. Failure to
comply could result in substantial property damage, severe
personal injury, or death.

4
LP-542 REV. 6.2.16
NOTICE
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, HTP, Inc. has provided this appliance with
multiple features designed to save energy by reducing the appliance water temperature as heating load decreases.
These features include:
A modulating combustion system that adjusts firing rate based on heat demand.
Adjustment of appliance set point based on inferred heat load as determined by an outdoor sensor. The outdoor
sensor is supplied by HTP, Inc. with this appliance.
This appliance does not include a standing pilot.
This appliance is designed and shipped to assure the highest efficiency operation possible. Such high efficiency is
achieved by limiting heating circuit water temperature to 140°F when there is no anticipated heat load, based upon
the outdoor sensor and the Outdoor Reset Curve (sensor response curve) in the appliance software.
This feature may be over-ridden as described below in specific installations:
The appliance control is equipped with an outdoor sensor override for use with building management systems or in
cascaded systems (for systems with total input of 300,000 BTU/hr or greater).
See statement below for an important notice on the use of the override.
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, this appliance is equipped with a feature
that saves energy by reducing the appliance water temperature as the heating load decreases. This feature is equipped with
an override which is provided primarily to permit the use of an external energy management system that serves the same
function. THIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST ONE OF THE FOLLOWING CONDITIONS IS TRUE:
An external energy management system is installed that reduces the appliance water temperature as the heating load
decreases.
This appliance is not used for space heating.
This appliance is part of a modular or multiple appliance system having a total input of 300,000 BTU/hr or greater.
This appliance is equipped with a tankless coil.
NOTICE
The CSD-1 ASME Code, Section CW-400 requires that hot water heating and supply boilers have a) a UL 353 temperature control
device, b) at least one (1) temperature-actuated control to shut off the fuel supply when system water reaches a preset operating
temperature, c) a high temperature limit control that prevents the water temperature from exceeding the maximum allowable
temperature by causing a safety shutdown and lockout, and d) its own sensing element and operating switch.
Certain AHJs, locales, and states will require that commercial boiler installations meet the CSD-1 ASME Code, Section CW-400. To
meet this code, HTP, Inc. has integrated a temperature control system into the 926 control provided with this heating boiler. This control
system complies with the requirements of CSD-1 Section CW-400 as a temperature operation control. The control monitors the
temperature difference between the inlet and the outlet sensor, which is affected by boiler water flow. If this temperature difference
exceeds 55°F (typically because of low water flow or very low heat load), the control will reduce the maximum fan speed. If the
temperature difference exceeds 60°F, the control will effectively sense there is little or no water flow or heat load and shut the boiler
down. The controller will restart automatically once the temperature difference has dropped below 55°F and the minimum off time (anti-
cycle time) has expired. In addition, if the control senses that the outlet water temperature has reached 199°F, the boiler is put into a
hard lockout and requires manual reset to restart.
Installers should review the regulations of the AHJ, local and state code authorities, and utility companies which pertain to this type of
boiler BEFORE performing installation.
TABLE OF CONTENTS
PART 1 –ITEMS SHIPPED WITH THE BOILER ........................................................................................................................7
PART 2 –SAFETY REGULATIONS ...........................................................................................................................................8
A. OPERATION AND INSTALLATION WARNINGS.......................................................................................................................8
B. IMPROPER COMBUSTION .....................................................................................................................................................10
C. GAS..........................................................................................................................................................................................10
D. WHEN SERVICING THE BOILER............................................................................................................................................10
E. BOILER SYSTEM.....................................................................................................................................................................10
F. BOILER WATER CHEMISTRY.................................................................................................................................................10

5
LP-542 REV. 6.2.16
G. FREEZE PROTECTION FLUIDS.............................................................................................................................................11
H. HIGH ELEVATION INSTALLATIONS.......................................................................................................................................11
PART 3 –TECHNICAL SPECIFICATIONS...............................................................................................................................11
PART 4 –PREPARE BOILER LOCATION ...............................................................................................................................15
A. UNCRATING THE BOILER......................................................................................................................................................15
B. BEFORE LOCATING THE BOILER .........................................................................................................................................15
C. LEVELING................................................................................................................................................................................16
D. CLEARANCES FOR SERVICE ACCESS................................................................................................................................17
E. RESIDENTIAL GARAGE AND CLOSET INSTALLATIONS .....................................................................................................17
F. EXHAUST VENT AND INTAKE PIPE.......................................................................................................................................18
G. PREVENT COMBUSTION AIR CONTAMINATION.................................................................................................................18
H. REMOVING A BOILER FROM A COMMON VENT SYSTEM..................................................................................................18
I. WALL-MOUNTING THE BOILER ..............................................................................................................................................19
PART 5 –VENTING...................................................................................................................................................................20
A. INTAKE PIPE AND EXHAUST VENT GUIDELINES................................................................................................................20
B. APPROVED VENT MATERIALS..............................................................................................................................................22
C. ALLOWED COMBINED VENT LENGTHS...............................................................................................................................22
D. TIGHTENING BOILER COLLAR TO EXHAUST VENT AND INTAKE PIPE............................................................................23
E. VENT TERMINATION ..............................................................................................................................................................24
1. Direct Vent, Two Pipe Roof and Sidewall Vent Terminations................................................................................................24
2. Direct Vent, Optional Horizontal and Vertical Vent Kits.........................................................................................................25
3. Snorkel Venting .........................................................................................................................................................................26
4. Power Vent, Indoor Combustion Air Installation in Confined or Unconfined Space...........................................................27
5. Screen Installation.....................................................................................................................................................................29
PART 6 –INSTALL THE CONDENSATE DRAIN.....................................................................................................................29
PART 7 –GAS PIPING..............................................................................................................................................................30
A. ADDITIONAL PRECAUTION FOR EXCESS FLOW VALVE (EFV) .........................................................................................31
B. GAS PIPE SIZING TABLES.....................................................................................................................................................31
1. Gas Pipe Sizing..........................................................................................................................................................................31
2. Natural Gas Pipe Sizing ............................................................................................................................................................31
3. LP (Liquid Propane) Gas Pipe Sizing.......................................................................................................................................31
C. GAS CONNECTION REQUIREMENTS...................................................................................................................................32
PART 8 –WATER PIPING ........................................................................................................................................................33
A. GENERAL PLUMBING CONNECTION GUIDELINES.............................................................................................................33
B. BACKFLOW PREVENTER.......................................................................................................................................................34
C. CENTRAL HEATING PIPING SYSTEM WATER PIPING METHODS.....................................................................................34
D. CIRCULATOR SIZING.............................................................................................................................................................34
E. CH PRESSURE RELIEF VALVE..............................................................................................................................................43
F. BUILT-IN LOW WATER CUT-OFF (LWCO).............................................................................................................................43
G. OPTIONAL EXTERNAL UL353 MANUAL RESET LOW WATER CUT-OFF (LWCO) INTERFACE KIT .................................43

6
LP-542 REV. 6.2.16
PART 9 –CONNECT ELECTRICAL POWER / INITIAL STARTUP .........................................................................................44
A. GENERAL OPERATING CONDITIONS...................................................................................................................................44
B. WIRING INFORMATION..........................................................................................................................................................44
C. DIP SWITCHES .......................................................................................................................................................................45
D. WIRING A CASCADE SYSTEM...............................................................................................................................................46
PART 10 –OPERATING SYSTEM INSTRUCTIONS................................................................................................................51
A. CONTROL PANEL ...................................................................................................................................................................51
B. LCD DISPLAY DESCRIPTIONS ..............................................................................................................................................51
C. START-UP SEQUENCE ..........................................................................................................................................................51
D. CHANGING THE CH SET-POINT............................................................................................................................................52
E. CHANGING THE TIME.............................................................................................................................................................53
F. STATUS DISPLAY MODE........................................................................................................................................................53
G. INSTALLER MODE..................................................................................................................................................................54
H. ERROR MODE.........................................................................................................................................................................57
I. SETTING UP A CASCADE SYSTEM........................................................................................................................................60
J. OUTDOOR TEMPERATURE MODE (OPTIONAL)...................................................................................................................61
K. 0-10 VOLT INPUT ....................................................................................................................................................................62
L. STEP MODULATION................................................................................................................................................................62
M. ERROR TREE ANALYSIS.......................................................................................................................................................63
1. FLAME DETECTION...................................................................................................................................................................63
2. GAS DETECTION .......................................................................................................................................................................63
3. APS / BURNER OVERHEAT LIMIT / CONDENSATE BLOCK SWITCH...................................................................................64
4. STORAGE / OP / CH OVERHEAT / EXHAUST OVERHEAT SENSORS ..................................................................................64
PART 11 –START-UP PREPARATION....................................................................................................................................64
A. BOILER WATER CHEMISTRY ................................................................................................................................................65
B. GLYCOL ANTIFREEZE SOLUTIONS......................................................................................................................................65
C. CHECK FOR GAS LEAKS.......................................................................................................................................................65
D. FILL AND TEST WATER SYSTEM..........................................................................................................................................66
E. PURGE AIR FROM SYSTEM...................................................................................................................................................67
F. CHECK THERMOSTAT CIRCUIT(S) .......................................................................................................................................67
G. CONDENSATE REMOVAL......................................................................................................................................................67
H. FINAL CHECKS BEFORE STARTING BOILER ......................................................................................................................68
I. ADJUSTING GAS PRESSURE AT THE BOILER......................................................................................................................68
J. SETTING AND VERIFYING THE COMBUSTION SETTING....................................................................................................69
PART 12 –INSTALLATION AND START-UP CHECKLIST......................................................................................................70
PART 13 –TROUBLESHOOTING ............................................................................................................................................72
PART 14 –ANNUAL MAINTENANCE PROCEDURES............................................................................................................72
REPLACEMENT PARTS ................................................................................................................................................................76
Limited Warranty for UFT Boilers.................................................................................................................................................83
START-UP REPORT.......................................................................................................................................................................85

7
LP-542 REV. 6.2.16
MAINTENANCE REPORT ..............................................................................................................................................................86
MAINTENANCE NOTES................................................................................................................................................................. 89
CUSTOMER INSTALLATION RECORD FORM.............................................................................................................................90
PART 1 –ITEMS SHIPPED WITH THE BOILER
ITEM
DESCRIPTION
QUANTITY
Universal Fire Tube Boiler
UFT-W
1
H-2 Form, User, and Installation
Manuals
1 Each
Condensate Hose
(Part # 7855P-089)
1
Anchors and Wall Mounting
Bracket
(Part # 7850P-084)
4
Outdoor Sensor with
Screws and Anchors
(Part # 7855P-084)
1
Spare Parts Kit
(Gaskets and O-Rings)
(Part # 7855P-383)
1
30 PSI Pressure Relief Valve
(Part # 7855P-077)
1
1 ¼” X 1 ¼” X ¾” Tee (steel)
(Part # 7855P-313),
3/4" Street Elbow (steel)
(Part # 7350P-084)
1
3” CPVC
(Part # 7855P-101)
6” Length
Vent Screens (3”)
(Part # 7855P-085)
2 Screens

8
LP-542 REV. 6.2.16
LP Conversion Kit
(175W / 199W Models Only)
(Part #7855P-452)
1
Table 1 –Items Included with the Boiler
OPTIONAL EQUIPMENT
Below is a list of optional equipment available from HTP. These additional options may be purchased through your HTP distributor:
System Sensor (Part # 7250P-324)
Indirect Tank Sensor (Part # 7250P-325)
2" PVC Concentric Vent Kit (Part # KGAVT0501CVT)
3" PVC Concentric Vent Kit (Part # KGAVT0601CVT)
2” Stainless Steel Outside Termination Vent Kit (Part # V500)
3” Stainless Steel Outside Termination Vent Kit (Part # V1000)
4” Stainless Steel Outside Termination Vent Kit (Part # V2000)
6” Stainless Steel Outside Termination Vent Kit (Part # V3000)
3” Polypro Vent Kit (Part # 8400P-001)
3” Polypro Pipe (33’ length Part # 8400P-002, 49.5’ length Part # 8400P-003)
Condensate Neutralizer (Part # 7450P-212)
Condensate Removal Pump (Part # 554200)
Communication Cable (Part # 7850P-093)
2” Vent Screens (Two Screens) (Part # 7850P-088)
UL353 Low Water Cut-Off Kit (Part # 7855P-315)
Conversion Kit
NOTE: When using an optional system sensor, pipe insulation must be wrapped around it to improve temperature measurement
accuracy and increase overall system efficiency.
PART 2 –SAFETY REGULATIONS
A. OPERATION AND INSTALLATION WARNINGS
To avoid serious injury or death, read, understand, and follow all the precautions listed here.
Vapors from flammable liquids will explode and can cause a fire, resulting in personal injury or death. The boiler has a burner that can
come on at any time and ignite vapors. DO NOT use or store flammable liquids around the boiler.
Improper venting can cause a build-up of carbon monoxide. Breathing carbon monoxide can result in brain damage or death. DO NOT
operate the boiler unless it is properly vented to the outside and has an adequate fresh air supply for safe operation. Inspect the
exterior exhaust gas outlet port and fresh air inlet port on a regular basis to ensure they are functioning properly.
A concentration of carbon monoxide as small as .04% (400 parts per million) in the air can be fatal. When making high fire or low fire
adjustments, CO levels must be monitored using a flue gas analyzer such that a CO level of no more than 400 ppm is exceeded at any
time during operation.
Adjusting the “low fire offset” on the gas valve in even small increments can result in a significant increase in CO concentration. To
avoid serious injury or death, DO NOT make any adjustments to the gas valve without monitoring the exhaust gases with a fully
functional and calibrated flue gas analyzer.
Failure to follow these statements will result in property damage, severe personal injury, or death.
This boiler must be installed by a licensed plumber, licensed gas fitter, and/or professional service technician. Improper installation
and/or operation can cause a potentially hazardous situation, which, if not avoided, could result in serious injury or death, and will void
the warranty.
HTP, Inc. cannot anticipate every circumstance that might involve a potential hazard. Each installation has its own specialized
characteristics, requirements, and possible hazards. Therefore, all possible incidents are not included in these warnings. Proper and
safe installation, operation, and service are the responsibility of the professional service technician.
Proper care of the boiler is the user’s responsibility. Ensure the user carefully reads and understands the User’s Information Manual
before operating and maintaining the boiler.
Make sure the user knows the location of the gas shut-off valve and how to operate it. Immediately close the gas shut-off valve if the
boiler is subjected to fire, overheating, flood, physical damage, or any other damaging condition that might affect the operation of the
unit. Have the boiler checked by a qualified technician before resuming operation.

9
LP-542 REV. 6.2.16
Do not power up the unit unless the gas and water supply valves are fully opened. Make sure the fresh air intake port and exhaust gas
port are open and functional.
No one but a professional service technician should attempt to install, service, or repair this boiler. There are no serviceable parts which
can be changed by the user / owner. User / Owner: Contact the original professional service technician if the boiler needs repair or
maintenance. If the original technician is unavailable, ask your gas supplier for a list of qualified service providers.
Keep the area around the boiler clean and free of all materials that can burn. DO NOT store or place gasoline, oils, spray paint, or other
flammable products near the boiler.
DO NOT use spray paint, hair spray, or any other flammable spray near the boiler or near the exterior fresh air intake port. DO NOT
place any items in or around the exterior exhaust gas outlet port and/or fresh air inlet port that could restrict or block the flow in or out of
the vent system.
DO NOT store or place newspapers, laundry, or other combustible items near the boiler or the exterior exhaust gas outlet and/or fresh
air inlet port.
The owner should inspect the system monthly for damage, water stains, signs of rust, corrosion, and exhaust vent and air intake
blockage. If inspection of the unit shows signs of damage, the boiler should be shut off until the problem is repaired by a qualified
technician.
After installation, all boiler safety devices should be tested.
This boiler is certified for indoor installations only. The boiler consists of gas ignition system components which must be protected from
water (dripping, spraying, etc.) during operation and service. Carefully consider installation location and the placement of critical
components (circulators, condensate neutralizers, etc.) before installing the boiler.
DO NOT allow children to operate this unit. DO NOT use this unit if it does not appear to be operating correctly. A qualified technician
should service and inspect the boiler annually.
If the boiler is exposed to the following, do not operate until all corrective steps have been made by a qualified service technician:
1. FIRE
2. DAMAGE
3. WATER
This boiler is equipped with a three prong plug. It should only be plugged directly into a properly grounded three prong receptacle. DO
NOT remove the ground plug from the plug.
DO NOT alter or modify the boiler or boiler controls. This can be dangerous and WILL VOID the warranty.
Failure to follow these statements could result in property damage, severe personal injury, or death.
NOTICE
Any claims for damage or shortage in shipment must be filed immediately against the transportation company by the consignee.
This boiler provides a overheat shutdown limit. In the event the boiler water exceeds the set point of the control limit, the cutoff will trip
and the boiler will shut down. Certain local codes require additional temperature limits. In addition, certain types of systems may
operate at temperatures below the minimum set point of the limit provided with the boiler. Contact a qualified service technician for
additional overheat controls.
NOTE: When inquiring about service or troubleshooting, reference the model and serial numbers from the appliance rating label.
DO NOT USE THIS BOILER IF ANY PART HAS BEEN SUBMERGED IN WATER. Immediately call a qualified service technician. The
boiler MUST BE replaced if it has been submerged. Attempting to operate a boiler that has been submerged could create numerous
harmful conditions, such as a potential gas leakage causing a fire and/or explosion, or the release of mold, bacteria, or other harmful
particulates into the air. Operating a previously submerged boiler could result in property damage, severe personal injury, or death.
NOTE: Boiler damage due to flood or submersion is considered an Act of God, and IS NOT covered under product warranty.
Be sure to disconnect electrical power before opening boiler cabinet or performing service. Label all wires while performing service to
ensure proper re-wiring of the boiler. Wiring errors can cause improper or dangerous operation. Failure to do so could result in an
electrical shock, improper boiler operation, property damage, serious personal injury, or death.
Due to the low water content of the boiler, improper sizing of the boiler with regard to heating system load will result in excessive cycling
and accelerated component failure. HTP DOES NOT warrant failures caused by improperly sized boiler applications. DO NOT oversize
the boiler to the system. Modular boiler installations greatly reduce the likelihood of boiler oversizing.

10
LP-542 REV. 6.2.16
B. IMPROPER COMBUSTION
Do not obstruct the flow of combustion and ventilating air. Adequate air must be
provided for safe operation. Failure to keep the exhaust vent and intake pipe
clear of ice, snow, or other debris could result in property damage, serious
personal injury, or death.
C. GAS
Should overheating or gas supply fail to shut off, do not turn off or disconnect
electrical supply to the circulator. Instead, shut off the gas supply at a location
external to the boiler.
D. WHEN SERVICING THE BOILER
To avoid electric shock, disconnect electrical supply before performing
maintenance.
To avoid severe burns, allow boiler to cool.
Do not use petroleum-based cleaning or sealing compounds in a boiler
system. Gaskets and seals in the system may be damaged, possibly
resulting in substantial property damage.
Do not use “homemade cures” or “patent medicines”. Substantial property damage, damage to boiler, and/or serious personal
injury may result.
Always verify proper operation after servicing the boiler.
E. BOILER SYSTEM
Thoroughly flush the system (without boiler connected) to remove sediment. The high-efficiency heat exchanger can be
damaged by build-up or corrosion due to sediment. HTP recommends a suction strainer in all systems.
Do not use petroleum-based cleaning or sealing compounds in boiler system. Gaskets and seals in the system may be
damaged, possibly resulting in substantial property damage.
Do not use “homemade cures” or “boiler patent medicines”. Substantial property damage, damage to boiler, and/or serious
personal injury may result.
Continual fresh make-up water will reduce boiler life. Mineral buildup in the heat exchanger reduces heat transfer, overheats the
stainless steel heat exchanger, and causes failure. Addition of oxygen from make-up water can cause internal corrosion in system
components. Leaks in the boiler or piping must be repaired at once.
F. BOILER WATER CHEMISTRY
Sodium less than 20mGL.
Water pH between 6 and 8
oMaintain water pH between 6 and 8. Check with litmus paper or have it chemically analyzed by water treatment
company.
oIf the pH differs from above, consult local water treatment company for treatment needed.
Hardness less than 7 grains
oConsult local water treatment companies for unusually hard water areas (above 7 grains hardness).
Chlorine concentration less than 100 ppm
oUsing chlorinated fresh water should be acceptable as levels are typically less than 5 ppm.
oDo not connect the boiler to directly heat swimming pool or spa water.
oDo not fill boiler or operate with water containing chlorine in excess of 100 ppm.
NOTE: It is recommended to clean heat exchanger at least once a year to prevent lime scale buildup. To clean the heat exchanger,
follow the maintenance procedure in Part 13, Section B of this manual.
ACIDITY
6 to 8 pH
CONDUCTIVITY
Less than 400 uS/cm at 25oC
CHLORIDE
Less than 100 ppm
IRON
Less than 0.5 mg/L
COPPER
Less than 0.1 mg/L
SODIUM
Less than 20 mg/L
HARDNESS
Less than 7 Grains
Table 2 –Water Quality Requirements