HTP MC120 User Manual
MC Series Gas-Fired
When installing models manufactured after July 7, 2008, you will notice additional selections on the control installer menu that will not
apply to this unit. DO NOT CHANGE THESE FACTORY SETTINGS. Refer to the Control Program Reference Chart within this manual
for selections that apply to this model.
This manual must be used by a qualified installer/service technician. Read all instructions in this manual before installing. Perform steps
in the given order. Failure to comply could result in substantial property damage, severe personal injury, or death.
NOTE TO CONSUMER: PLEASE KEEP ALL INSTRUCTIONS FOR FUTURE REFERENCE.
Circulating Heater
INSTALLATION
START-UP
MAINTENANCE
PARTS
Models
MC50 / MC80
MC99 / MC120
NOTICE: HTP reserves the right to make product changes or updates without notice and will not be held liable for typographical errors
in literature.
120 Braley Rd. P.O. Box 429 East Freetown, MA 02717-0429 www.htproducts.com
LP-171 Rev. 4.10.14
2
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 HEATER.
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.
LP-171 Rev. 4.10.14
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.
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 severe personal injury, death or substantial property damage.
FOREWORD
This manual is intended to be used in conjunction with other literature provided with the MC Series Gas-Fired Heater. 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.
3
FOR THE INSTALLER
This heater must be installed by qualified and licensed personnel. The installer should be guided by the instructions furnished with the
heater, 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:
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.
LP-171 Rev. 4.10.14
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.
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 undergoing tests specified in ANSI
Z21.10.3 – latest edition.
TABLE OF CONTENTS
PART 1 – GENERAL SAFETY INFORMATION .......................................................................................................................... 6
A. PRECAUTIONS .......................................................................................................................................................................... 6
B. IMPROPER COMBUSTION ........................................................................................................................................................ 7
C. GAS ............................................................................................................................................................................................ 7
D. WHEN SERVICING THE HEATER ............................................................................................................................................. 7
E. HEATER SYSTEM ...................................................................................................................................................................... 7
F. WATER CHEMISTRY* ................................................................................................ ................................................................ 7
G. WINTERIZING ............................................................................................................................................................................ 8
PART 2 – BEFORE YOU START ................................................................................................................................................ 8
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A. WHAT’S IN THE BOX ................................................................................................................................................................. 8
B. HOW THE HEATER OPERATES ............................................................................................................................................... 8
C. OPTIONAL EQUIPMENT ......................................................................................................................................................... 10
PART 3 – PREPARE HEATER LOCATION .............................................................................................................................. 10
A. BEFORE LOCATING THE HEATER ........................................................................................................................................ 10
B. LEVELING ................................................................................................................................................................................ 11
C. CLEARANCES FOR SERVICE ACCESS ................................................................................................................................. 12
D. RESIDENTIAL GARAGE, CLOSET, AND ALCOVE INSTALLATIONS .................................................................................... 12
E. EXHAUST VENT AND INTAKE PIPE ....................................................................................................................................... 13
F. PREVENT COMBUSTION AIR CONTAMINATION .................................................................................................................. 13
G. REMOVING AN EXISTING HEATER FROM AN EXISTING COMMON VENT SYSTEM ........................................................ 13
PART 4 – PREPARE HEATER .................................................................................................................................................. 14
A. REMOVE HEATER FROM BOX ............................................................................................................................................... 14
B. WALL MOUNTING CONSIDERATIONS ................................................................................................................................... 14
C. WALL MOUNTING INSTRUCTIONS ........................................................................................................................................ 14
D. INSTALLATION STEPS ............................................................................................................................................................ 15
PART 5 – HEATER PIPING ....................................................................................................................................................... 15
A. GENERAL PIPING INFORMATION .......................................................................................................................................... 15
B. RELIEF VALVE ......................................................................................................................................................................... 16
C. SEPARATE LOW WATER CUTOFF ........................................................................................................................................ 17
D. BACKFLOW PREVENTER ....................................................................................................................................................... 17
E. SYSTEM WATER PIPING METHODS ..................................................................................................................................... 17
LP-171 Rev. 4.10.14
F. CIRCULATORS......................................................................................................................................................................... 17
G. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE HEATERS .................................................... 18
H. CIRCULATOR SIZING .............................................................................................................................................................. 18
I. ZONING WITH ZONE VALVES.................................................................................................................................................. 19
J. ZONING WITH CIRCULATORS ................................................................................................................................................ 19
K. MULTIPLE HEATERS ............................................................................................................................................................... 19
L. FILL AND PURGE HEATING SYSTEM .................................................................................................................................... 20
M. PIPING DETAILS ..................................................................................................................................................................... 21
PART 6 – PIPING WITH OPTIONAL VISION 1 SYSTEM ......................................................................................................... 28
A. VISION 1 SYSTEM PIPING ...................................................................................................................................................... 28
B. ZONING WITH ZONE VALVES USING VISION 1 .................................................................................................................... 28
C. ZONING WITH CIRCULATORS USING VISION 1 ................................................................................................................... 28
D. PIPING DETAILS WITH THE VISION 1 SYSTEM .................................................................................................................... 29
PART 7 – VENTING, COMBUSTION AIR, AND CONDENSATE REMOVAL ........................................................................... 39
A. GENERAL ................................................................................................................................................................................. 39
B. APPROVED MATERIALS FOR EXHAUST VENT AND INTAKE PIPE .................................................................................... 39
C. REQUIREMENTS FOR INSTALLATION IN CANADA .............................................................................................................. 40
D. EXHAUST VENT AND INTAKE PIPE LOCATION.................................................................................................................... 41
E. ROTATING THE FLUE ADAPTER ........................................................................................................................................... 44
F. EXHAUST VENT AND INTAKE PIPE SIZING .......................................................................................................................... 45
G. LONGER VENT RUNS ................................ ................................................................ ................................ ............................. 45
H. EXHAUST VENT AND INTAKE PIPE INSTALLATION ............................................................................................................ 46
I. DIAGRAMS FOR SIDEWALL VENTING ................................................................ ................................................................ .... 47
J. DIAGRAMS FOR VERTICAL VENTING .................................................................................................................................... 48
PART 8 – GAS PIPING .............................................................................................................................................................. 48
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A. GAS CONNECTION ................................................................................................................................................................. 48
B. GAS PIPING ............................................................................................................................................................................. 50
C. CHECK INLET GAS PRESSURE ............................................................................................................................................. 50
D. GAS VALVE .............................................................................................................................................................................. 51
PART 9 – FIELD WIRING .......................................................................................................................................................... 52
A. INSTALLATION MUST COMPLY WITH: .................................................................................................................................. 52
B. FIELD WIRING.......................................................................................................................................................................... 52
C. LINE VOLTAGE WIRING .......................................................................................................................................................... 52
D. THERMOSTAT ......................................................................................................................................................................... 52
PART 10 – FIELD WIRING – VISION 1 OPTION ...................................................................................................................... 55
PART 11 – START-UP PREPARATION.................................................................................................................................... 57
A. CHECK/CONTROL WATER CHEMISTRY ............................................................................................................................... 57
B. FREEZE PROTECTION (WHEN USED) .................................................................................................................................. 58
C. FILL AND TEST WATER SYSTEM .......................................................................................................................................... 58
D. AIR PURGING PROCEDURE FOR HEAT EXCHANGER ........................................................................................................ 58
E. PURGE AIR FROM WATER SYSTEM ..................................................................................................................................... 59
LP-171 Rev. 4.10.14
INSTALLER – Read all instructions in this manual before installing. Perform steps in the order given.
USER – This manual is for use only by a qualified heating installer/service technician. Refer to user’s information manual for your
reference. Have this heater serviced/inspected by a qualified service technician annually.
FAILURE TO ADHERE TO THE GUIDELINES ON THIS PAGE AND HAVE THIS HEATER SERVICED/INSPECTED ANNUALLY
CAN RESULT IN SUBSTANTIAL PROPERTY DAMAGE, SEVERE PERSONAL INJURY, OR DEATH.
F. CHECK FOR GAS LEAKS ........................................................................................................................................................ 60
G. CHECK THERMOSTAT CIRCUIT(S) ....................................................................................................................................... 60
H. CONDENSATE REMOVAL ...................................................................................................................................................... 60
I. FINAL CHECKS BEFORE STARTING HEATER ....................................................................................................................... 60
PART 12 – START-UP PROCEDURE ....................................................................................................................................... 61
A. OPERATING INSTRUCTIONS ................................ ................................ ................................................................................. 61
B. ADJUSTING THE SET POINT .................................................................................................................................................. 61
C. STATUS MENU ........................................................................................................................................................................ 62
D. TEST MODE ............................................................................................................................................................................. 62
PART 13 – START-UP PROCEDURES WITH VISION 1 OPTION ........................................................................................... 62
A. PROGRAMMING THE VISION I OPTION ................................................................................................................................ 63
B. VISION 1 PROGRAM ACCESS ................................................................................................................................................ 63
C. VISION 1 PROGRAM NAVIGATION ........................................................................................................................................ 63
PART 14 – TROUBLESHOOTING ............................................................................................................................................ 65
A. ERROR CODE .......................................................................................................................................................................... 65
B. HEATER ERROR...................................................................................................................................................................... 65
C. HEATER FAULT ....................................................................................................................................................................... 65
PART 15 – MAINTENANCE ...................................................................................................................................................... 67
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A. MAINTENANCE PROCEDURES .............................................................................................................................................. 67
B. MAINTENANCE SCHEDULE FOR THE SERVICE TECHNICIAN ........................................................................................... 68
C. COMBUSTION CHAMBER COIL CLEANING INSTRUCTIONS .............................................................................................. 68
D. MAINTENANCE SCHEDULE FOR THE OWNER .................................................................................................................... 69
HEATER START-UP REPORT .................................................................................................................................................. 74
MAINTENANCE REPORT ......................................................................................................................................................... 74
MAINTENANCE NOTES ........................................................................................................................................................................................ 78
HTP CUSTOMER INSTALLATION RECORD FORM ............................................................................................................................................. 79
PART 1 – GENERAL SAFETY INFORMATION
A. PRECAUTIONS
This heater is for indoor installations only. Clearance to combustible materials: 0” top, bottom, sides and back. Front must have room
for service, 24” recommended. (A combustible door or removable panel is acceptable front clearance.) This heater has been approved
for closet installation. This heater is designed to be wall mounted. Do not install on the floor. Category IV vent systems only.
NOTE: When inquiring about service or troubleshooting, reference the model and serial numbers from the heater rating label.
LP-171 Rev. 4.10.14
7
DO NOT USE THIS HEATER IF ANY PART HAS BEEN SUBMERGED IN WATER. Immediately call a qualified service technician.
The heater MUST BE replaced if it has been submerged. Attempting to operate a heater 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 heater could result in property damage, severe personal injury, or
death.
NOTE: Heater 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 heater cabinet or performing service. Failure to do so could result in an electrical
shock that could result in property damage, serious personal injury, or death.
NOTE: If the heater is exposed to the following, do not operate until all corrective steps have been made by a qualified serviceman:
1. FIRE
2. DAMAGE
3. WATER
Any claims for damage or shortage in shipment must be filed immediately against the transportation company by the consignee.
Due to the low water content of the heater, improper sizing of the heater with regard to heating system load will result in excessive
cycling and accelerated component failure. HTP DOES NOT warrant failures caused by improperly sized heater applications. DO NOT
oversize the heater to the system. Modular heater installations greatly reduce the likelihood of heater oversizing.
Do not obstruct combustion and ventilating air flow. 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.
B. IMPROPER COMBUSTION
C. GAS
Should overheating or gas supply fail to shut off, do not turn off or disconnect electrical supply to circulator. Instead, shut off the gas
supply at a location external to the heater.
D. WHEN SERVICING THE HEATER
To avoid electric shock, disconnect electrical supply before
performing maintenance.
To avoid severe burns, allow heater to cool.
E. HEATER SYSTEM
Do not use petroleum-based cleaning or sealing compounds in a
heater system. Gaskets and seals in the system may be damaged.
This can result in substantial property damage.
Do not use “homemade cures” or “patent medicines”. Substantial
property damage, damage to heater, and/or serious personal
injury may result.
Continual fresh make-up water will reduce heater life. Mineral
buildup reduces heat transfer, overheats the stainless steel heat
exchanger, and causes failure. Addition of oxygen by make-up
water can cause internal corrosion in system components. Leaks
in the heater or piping must be repaired at once.
If you have an old system with cast iron radiators, thoroughly flush
the system (without heater connected) to remove sediment. The
high-efficiency heat exchanger can be damaged by build-up or corrosion due to sediment.
When the heater is used to supply potable water, do not connect it to any heating system or component(s) previously used
with a non-potable water-heating heater.
NOTE: Damages resulting from incorrect installation or from use of products not approved by HTP, Inc. ARE NOT covered by warranty.
F. WATER CHEMISTRY*
Sodium less than 20mGL.
LP-171 Rev. 4.10.14
NEVER use any toxic chemical, including automotive, standard glycol antifreeze, or ethylene glycol made for hydronic (non-potable)
systems. These chemicals can attack gaskets and seals in heaters, are poisonous if consumed, and can cause injury or death.
Consider piping and installation when determining heater location.
Water pH between 6.0 and 8.0
o Maintain water pH between 6.0 and 8.0. Check with litmus paper or have it chemically analyzed by water treatment
company.
o If the pH differs from above, consult local water treatment company for treatment needed.
Hardness less than 7 grains
o Consult local water treatment companies for unusually hard water areas (above 7 grains hardness).
Chlorine concentration less than 100 ppm
o Using chlorinated fresh water should be acceptable as levels are typically less than 5 ppm.
o Do not connect the heater to directly heat swimming pool or spa water.
o Do not fill heater 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 15, Section B of this manual.
Hardness: 7 grains
Chloride levels: 100 ppm
pH levels: 6-8
TDS: 2000 ppm
Sodium: 20 mGL
G. WINTERIZING
8
To winterize the heater, drain the entire system. Then apply air pressure to the drain valve and allow air and water to escape from the
purge valve (see piping instructions).
Once you have evacuated as much water as possible, pump non-toxic, NSF food grade propylene glycol, FDA rated as GRAS
(Generally Recognized As Safe), into the system. Consult the glycol manufacturer for specific instructions on concentration percentage
as well as freeze and burst protection methods. Check the volume and concentration of antifreeze to assure protection is adequate to
protect the entire system from freezing. When pumping, allow air and remaining water to escape from purge valve. When the stream
coming out of the purge valve matches the color of the non-toxic glycol, the system is adequately filled.
Finally, it is recommended to start the circulation pump and allow the system to circulate for at 30 minutes to completely blend any
trapped water that might be in the system with the glycol.
PART 2 – BEFORE YOU START
A. WHAT’S IN THE BOX
Also included with the heater:
Temperature and Pressure Relief Valve
Pressure and Temperature Gauge
Intake PVC Tee with Screens
Exhaust PVC Coupling with Screens
Plastic hose and Instructions for Purging Heat Exchanger
Installation Manual
Warranty
B. HOW THE HEATER OPERATES
Modulation Condensing Technology is an intelligent system that delivers highly efficient water heating, while maximizing efficiency
by measuring the data parameters of your system.
Stainless Steel Heat Exchanger
The highly efficient and durable stainless steel heat exchanger is designed to extract the last bit of energy from flue gas before it is
exhausted.
LP-171 Rev. 4.10.14
Modulating Combustion System
Modulation during operation is based on supply temperature and desired temperature set point. The set point used for the control
depends upon the programmed central heating curve. The heating curve slope can be changed by the installer to better fit system
needs. The control monitors the system to regulate burner output during operation to match system demand. This increase in efficiency
allows for substantial fuel savings.
Gas Valve
The gas valve senses suction from the blower, allowing gas to flow only if the gas valve is energized and combustion air is flowing.
Swirl Plate System
The gas valve swirl plate controls air and gas flow into the burner, assuring better mixing for improved combustion.
Supply Water Temperature Sensor
This sensor monitors heater output water temperature (system outlet/supply). The control module adjusts the heater firing rate so the
outlet/supply temperature is correct.
Return Water Temperature Sensor
This sensor monitors the return water temperature (system inlet/return). The control module reduces or increases heater input,
depending on how close the inlet/return water temperature is to the outlet water temperature.
Temperature and Pressure Gauge
Allows the user to monitor system temperature and pressure.
Control
The integrated control system monitors inlet/return and outlet/supply water temperature and regulates fan speed to regulate the unit’s
BTU output. This allows the unit to deliver the required amount of heated energy and nothing more.
Flue Pipe Adapter
The flue pipe adapter may be positioned so that the installer is able to find a position that will best facilitate the exhaust and combustion
air pipe connections with the least number of elbows in even the most challenging of situations.
Burner
Constructed of metal fiber and high grade stainless steel, the burner uses pre-mixed air and gas and provides a wide range of firing
rates.
Electrical Field Connections with Terminal Strips
The electrical cover plate allows access to the line voltage and low voltage terminal strips. Attach line voltage conduits to the three
holes at the right of the line voltage terminal strip for power, CH pump and DHW pump. Route low voltage wires through the opening to
the left of the low voltage terminal strip (see Field Wiring Instructions, Part 9).
Condensate Drain Connection
As this is a condensing high efficiency appliance, the unit has a condensate removal system. Condensate is nothing more than water
vapor, derived from combustion products and similar to an automobile when it is initially started. It is very important that the condensate
line slopes away from the heater and down to a suitable inside drain.
If the condensate outlet on the heater is lower than the drain, you must use a condensate removal pump (kit p/n 554200 available from
HTP.) In addition, local authorities may require a condensate neutralizer to neutralize the condensate. Condensate neutralizers are
made up of lime crystals, marble or phosphate chips. Neutralizers can be installed in the field by the installer and purchased from HTP
(p/n N1100).
It is also very important not to expose the condensate line to freezing temperatures or any type of blockage. Plastic tubing must be the
only material used for the condensate line. Steel, brass, copper or other materials will be subject to corrosion or deterioration. A second
vent may be necessary to prevent condensate line vacuum lock on a long horizontal run. Also, an increase in pipe size may be
necessary to allow condensate to drain properly. Support of the condensation line may be necessary to avoid blockage of the
condensate flow.
Spark Ignition
The burner flame is ignited by applying a high voltage to the system spark electrode. This causes a spark from electrode to ground.
The Vision 1 Optional System
By controlling the temperature delivered to the central heating circuits based on outside temperature, the Vision 1 System allows the
installer to take this highly efficient heater and make it even more efficient. The Vision 1 System is also a two temperature system,
using one temperature for central heating and the other for use with an indirect water heater. This allows the user to increase the
temperature supplied to the indirect water heater to get a faster recovery by prioritizing the flow at a higher temperature than may be
needed for the central heating circuits (this requires two separate circulators). You must follow the piping, wiring, and programming
instructions located in the Vision One section of this manual.
LP-171 Rev. 4.10.14
9
Carefully consider installation when determining heater location. Please read the entire manual before attempting installation. Failure to
properly take factors such as heater venting, piping, condensate removal, and wiring into account before installation could result in
wasted time, money, and possible property damage and personal injury.
Incorrect ambient conditions can lead to damage to the heating system and put safe operation at risk. Ensure that the heater installation
location adheres to the information included in this manual. Failure to do so could result in property damage, serious personal injury, or
death.
Failure of heater or components due to incorrect operating conditions IS NOT covered by product warranty.
The service life of the heater’s exposed metallic surfaces, such as the casing, as well as internal surfaces, such as the heat exchanger,
are directly influenced by proximity to damp and salty marine environments. In such areas, higher concentration levels of chlorides from
sea spray coupled with relative humidity can lead to degradation of the heat exchanger and other heater components. In these
environments, heaters must not be installed using direct vent systems which draw outdoor air for combustion. Such heaters must be
installed using room air for combustion. Indoor air will have a much lower relative humidity and, hence, potential corrosion will be
minimized.
This heater is certified for indoor installations only. Do not install the heater outdoors. Failure to install this heater indoors could result in
substantial property damage, severe personal injury, or death.
C. OPTIONAL EQUIPMENT
Below is a list of optional equipment available from HTP. These additional options may be purchased through your HTP distributor:
Indirect Tank Sensor (Part # 7250P-325)
Outdoor sensor (Part # 7250P-319)
2” Stainless Steel Outside Termination Vent Kit (V500)
3” Stainless Steel Outside Termination Vent Kit (V1000)
2” PVC Concentric Vent Kit (Part # KGAVT0501CVT)
3" PVC Concentric Vent Kit (Part # KGAVT0601CVT)
3” Polypro Vent Kit (Part # 8400P-001)
3” Polypro Pipe (33’ length Part # 8400P-002, 49.5’ length Part # 8400P-003)
Alarm System (Part # 7350P-602) (to monitor any failure)
Condensate Pump (Part # 7250P-320)
Condensate Neutralizer (Part # 554200)
Vision 1 Outdoor Sensing System (Part # 7250P-622)
PART 3 – PREPARE HEATER LOCATION
A. BEFORE LOCATING THE HEATER
10
1. Installation Area (Mechanical Room) Operating Conditions
Ensure ambient temperatures are higher than 32oF/0oC and lower than 104oF/40oC.
Prevent the air from becoming contaminated by the products, places, and conditions listed in this manual, Part 3, Section F.
Avoid continuously high levels of humidity
Never close existing ventilation openings
2. Check for nearby connections to:
System water piping
Venting connections
Gas supply piping
Electrical power
Condensate drain
3. Check area around heater. Remove any combustible materials, gasoline, and other flammable liquids.
LP-171 Rev. 4.10.14
11
Failure to keep heater area clear and free of combustible materials, liquids, and vapors can result in substantial property damage,
severe personal injury, or death.
In order for the condensate to properly flow out of the collection system, the heater must be installed level. The location must also
support the heater when it is full of water.
4. Gas control system components must be protected from dripping water during operation and service.
5. If the heater is to replace an existing heater, check for and correct any existing system problems, such as:
System leaks
Location that could cause the system and heater to freeze and leak.
Incorrectly-sized expansion tank
6. Clean and flush system when reinstalling a heater.
NOTE: When installing in a zero clearance location, it may not be possible to read or view some product labeling. It is recommended to
make note of the heater model and serial number.
Figure 1 –Specifications – LP-171-B
Before considering location, many factors need to be addressed. Piping, Venting, and Condensation Removal are just a few of the
issues that need attention prior to the installation of the heater. Please read the entire manual, as it could save time and money.
B. LEVELING
LP-171 Rev. 4.10.14
Space must be provided with combustion/ventilation air openings correctly sized for all other appliances located in the same space as
the heater. The heater cover must be securely fastened to prevent the heater from drawing air form the heater room. This is particularly
important if the heater is in a room with other appliances. Failure to comply with the above warnings could result in substantial property
damage, severe personal injury, or death.
Check with your local Authority Having Jurisdiction for requirements when installing heater in a garage, closet, or alcove. Please read
the entire manual before attempting installation. Failure to properly take factors such as heater venting, piping, condensate removal,
and wiring into account before installation could result in wasted time, money, and possible property damage and personal injury.
For closet or alcove installations, a two pipe venting system must be used. Failure to follow this warning could result in substantial
property damage, severe personal injury, or death.
The space must be provided with correctly sized combustion/ventilation air openings for all other heaters located in the space with the
heater. Do not install the heater in an attic. Failure to comply with these warnings could result in substantial property damage, severe
personal injury, or death.
C. CLEARANCES FOR SERVICE ACCESS
See Figure 2 for recommended service clearances. If you do not provide the minimum clearances shown, it may not be possible to
service the heater without removing it from the space.
12
Figure 2 – Required Clearances
D. RESIDENTIAL GARAGE, CLOSET, AND ALCOVE INSTALLATIONS
PRECAUTIONS
If the heater is located in a residential garage, per ANSI Z223.1:
Mount the bottom of the heater a minimum of 18” above the floor of the garage, to ensure the burner and ignition devices are
well off the floor.
Locate or protect the heater so it cannot be damaged by a moving vehicle.
NOTE: For installations using room air for combustion, refer to the heater venting section, Part 6 in this manual.
LP-171 Rev. 4.10.14
13
Vents must be properly supported. Heater exhaust and intake connections are not designed to carry heavy weight. Vent support
brackets must be within 1’ of the heater and the balance at 4’ intervals. Heater must be readily accessible for visual inspection for the
first 3’ from the heater.
PRODUCTS TO AVOID
AREAS LIKELY TO HAVE CONTAMINANTS
Spray cans containing fluorocarbons
Dry cleaning/laundry areas and establishments
Permanent wave solutions
Swimming pools
Chlorinated waxes/cleaners
Metal fabrication plants
Chlorine-based swimming pool chemicals
Beauty shops
Calcium chloride used for thawing
Refrigeration repair shops
Sodium chloride used for water softening
Photo processing plants
Refrigerant leaks
Auto body shops
Paint or varnish removers
Plastic manufacturing plants
Hydrochloric or Muriatic acid
Furniture refinishing areas and establishments
Cements and glues
New building construction
Antistatic fabric softeners used in clothes dryers
Remodeling areas
Chlorine-type bleaches, laundry detergents, and cleaning solvents
Garages and workshops
Adhesives used to fasten building products
You must pipe outside air to the heater air intake. Ensure that the intake air will not contain any of the contaminants listed in Table 1.
For example, do not pipe intake near a swimming pool. Also, avoid areas subject to exhaust fumes from laundry facilities. These areas
always contain contaminants. Contaminated air will damage the heater, resulting in possible substantial property damage, severe
personal injury, or death.
Do not install the heater into a common vent with any other appliance. This will cause flue gas spillage or appliance malfunction,
resulting in possible substantial property damage, severe personal injury, or death.
Failure to follow all instructions can result in flue gas spillage and carbon monoxide emissions, causing severe personal injury or death.
NOTE: DAMAGE TO THE HEATER CAUSED BY EXPOSURE TO CORROSIVE VAPORS IS NOT COVERED BY WARRANTY.
(Refer to the limited warranty for complete terms and conditions).
E. EXHAUST VENT AND INTAKE PIPE
The heater is rated ANSI Z21.13 Category IV (pressurized vent, likely to form condensate in the vent) and requires a special vent
system designed for pressurized venting.
You must also install air intake piping from outdoors to the heater flue adaptor. The resultant installation is categorized as direct vent
(sealed combustion). NOTE: To prevent combustion air contamination, see Table 1.
Exhaust and intake must terminate near each other and may be vented vertically through the roof or out a side wall. Exhaust vent and
intake piping methods are detailed in the Venting Section. Do not attempt to install the heater using any other means. Be sure to locate
the heater such that the exhaust vent and intake piping can be routed through the building and properly terminated. The exhaust vent
and intake piping lengths, routing and termination method must all comply with the methods and limits given in the venting section.
F. PREVENT COMBUSTION AIR CONTAMINATION
Install intake air piping for the heater as described in the Venting section. Do not terminate exhaust in locations that can allow
contamination of intake air.
Table 1 - Contaminant Table
G. REMOVING AN EXISTING HEATER FROM AN EXISTING COMMON VENT SYSTEM
When removing an existing heater, follow the steps below with each appliance remaining connected to the common venting system in
operation, while other appliances remaining connected to common venting system are not operating.
1. Seal any unused openings in the common venting system.
LP-171 Rev. 4.10.14
UNCRATING HEATER – Any claims for damage or shortage in shipment must be filed immediately against the transportation company
by the consignee.
COLD WEATHER HANDLING – If the heater has been stored in a very cold location (BELOW 0oF) before installation, handle with care
until the plastic components come to room temperature.
The wall must be capable of carrying the weight of the heater and its related components. The weights of the heaters are
approximately:
MC-50 – 71 lbs MC-80 – 74 lbs
MC-99 – 84 lbs MC-120 – 84 lbs
Failure to comply with above could result in substantial property damage, severe personal injury, or death.
This heater is heavy and awkward to lift. It is recommended and safer to install the heater with two people. Use caution as to not drop
the heater, which could damage the heater and cause property damage and/or personal injury. Verify that the heater is securely
mounted before leaving unsupervised. Failure to comply with the above and properly mount the heater could result in substantial
property damage, severe personal injury, or death.
Figure 3
2. Visually inspect the venting system for proper size and horizontal pitch to determine if there is blockage, leakage, corrosion or other
deficiencies that could cause an unsafe condition.
3. If practical, close all building doors, windows and all doors between the
space in which the appliance remains connected to the common venting system
located and other spaces in the building. Turn on clothes dryers and any
appliances not connected to the common venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, at maximum speed. Do not
operate a summer exhaust fan. Close all fireplace dampers.
4. Place in operation the appliance being inspected. Follow the lighting
instructions. Adjust the thermostat so the appliance will operate continuously.
5. Test for spillage at the draft hood relief opening after 5 minutes of main
burner operation. Use the flame of a match or candle or smoke from a cigarette.
6. After it has been determined that each appliance remaining connected to
common venting system properly vents when tested as outlined, return doors,
windows, exhaust fans, fireplace dampers and any other gas burning appliance
to their previous condition of use.
7. Any improper operation of the common venting system should be corrected
to conform to the National Fuel Gas Code, ANSI Z223.1. When resizing any
portion of the common venting system, the system should approach the minimum size as determined using the appropriate tables in
Appendix G in the National Fuel Gas Code, ANSI Z 223.1.
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PART 4 – PREPARE HEATER
A. REMOVE HEATER FROM BOX
The heater is easy to handle. Care must be taken to place it in a safe location prior to installation to prevent damage to the bottom
mechanical connections.
B. WALL MOUNTING CONSIDERATIONS
These heaters are wall mounted. Use only the wall mounting instructions included in installation envelope.
C. WALL MOUNTING INSTRUCTIONS
The wall must be vertically plumb and capable of carrying the weight of the heater and its related components.
LP-171 Rev. 4.10.14
If the heater is not vertically plumb, improper and unsatisfactory operation may occur, causing excessive condensation build-up,
nuisance fault codes, and unnecessary maintenance.
Failure to follow the instructions in this section WILL VOID the warranty and may result in property damage, serious injury, or death.
The building piping system must meet or exceed the piping requirements in this manual.
Use two wrenches when tightening water piping at heater. Use one wrench to prevent the heater return or supply line from turning.
Failure to prevent piping connections from turning could cause damage to heater components.
Never use dielectric unions or galvanized steel fittings when connecting to a stainless steel storage tank or heater. Use only copper or
brass fittings. Teflon thread sealant must be used on all connections. All piping and components connected to the heater must be
approved for potable water systems.
The National Standard Plumbing Code, the National Plumbing Code of Canada, and the Uniform Plumbing Code limit the pressure of
the heat transfer fluid to less than the minimum working pressure of the potable water system up to 30 psi maximum. The heat transfer
fluid must be water or other non-toxic fluid having a toxicity of Class 1, as listed in Clinical Toxicology of Commercial Products, 5th
Edition.
The building frame (studs) must be 16" on center. If not, you must use 1/2" minimum plywood 24" x 48", fastened with at least (14) #12
x 3" (3/16" x 3") round head tapping screws to the frame of the building to provide proper support for the heater. Alternate methods of
mounting must not be used. (ex. toggle bolts, hollow wall anchors) or any other fastener other than #12 x 3" (3/16" x 3") round head
tapping screws.
D. INSTALLATION STEPS
1. Prior to lifting the heater onto the wall, use the enclosed template to level and locate the 2 primary (#12 x 3" [3/16" x 3"]) round head
tapping screws, leaving about 1/4" between the screw head and the wall surface to allow for access to the keyway slot located in the
back of the heater panel. It is extremely important that the line on the template is level when locating the first 2 screws. Failure to do so
will result in an uneven or out of level installation.
2. Remove the heater cover. Locate the 2 keyway slots over the screws. Then lower the heater onto the smallest part of the keyway
slot.
3. Once the heater is mounted on the first 2 screws, finish tightening the screws to the back panel. Then install the 6 additional screws
of the same size to the back panel holes. This will provide additional strength and support to the heater.
PART 5 – HEATER PIPING
15
Plumbing of this product should only be done by a qualified, licensed plumber in accordance with all local plumbing codes. The heater
may be connected to a storage tank to supply domestic hot water. HTP offers 60/80/119/175 gallon size storage tanks in either
stainless steel or glass-lined construction. These storage tanks can be directly connected to the heater supply and return connection.
A. GENERAL PIPING INFORMATION
1. The water supply should be shut off while connecting the heater. A manual control valve must be placed on the inlet connection to
the heater. Unions can be used on both the hot and cold water lines for future servicing and disconnection of the unit.
2. Purge the water line to remove all debris and air. Debris will damage the water heater.
3. If the heater is to be used as a potable water source, it must not be connected to a system that was previously used for non-potable
purposes.
4. Ensure that the water filter on the heater is clean and installed.
LP-171 Rev. 4.10.14
The heater control module uses temperature sensors to provide both high limit protection and modulating temperature control. The
control module also provides low water protection by sensing the water pressure. Some codes/jurisdictions may require additional
external controls.
To avoid water damage or scalding due to relief valve operation:
Discharge line must be connected to relief valve outlet and run to a safe place of disposal. Terminate the discharge line in a
manner that will prevent possibility of severe burns or property damage should the relief valve discharge.
Discharge line must be as short as possible and the same size as the valve discharge connection throughout its entire length.
Discharge line must pitch downward from the valve and terminate at least 6” above the floor drain, making discharge clearly
visible.
The discharge line shall terminate plain, not threaded, with a material serviceable for temperatures of 375oF or greater.
Do not pipe discharge to any location where freezing could occur.
No shutoff valve may be installed between the relief valve and heater or in the discharge line. Do not plug or place any
obstruction in the discharge line.
Test the operation of the relief valve after filling and pressurizing the system by lifting the lever. Make sure the valve
discharges freely. If the valve fails to operate correctly, immediately replace with a new properly rated relief valve.
Test relief valve at least once annually to ensure the waterway is clear. If valve does not operate, turn the heater “off” and call
a plumber immediately.
Take care whenever operating relief valve to avoid scalding injury or property damage.
For heaters installed with only a pressure relief valve, the separate storage vessel must have a temperature and pressure
relief valve installed. This relief valve shall comply with Relief Valves for Hot Water Supply Systems, ANSI Z21.22 / CSA4.4.
FAILURE TO COMPLY WITH THE ABOVE GUIDELINES COULD RESULT IN FAILURE OF RELIEF VALVE OPERATION,
RESULTING IN POSSIBILITY OF SUBSTANTIAL PROPERTY DAMAGE, SEVERE PERSONAL INJURY, OR DEATH.
Hot water outlet pipes can be hot to touch. Insulation must be used for hot water pipes below 36” to protect children against injuries due
to scalds.
APPROXIMATE TIME / TEMPERATURE RELATIONSHIPS IN SCALDS
120oF
More than 5 minutes
125oF
1 ½ to 2 minutes
130oF
About 30 seconds
135oF
About 10 seconds
140oF
Less than 5 seconds
145oF
Less than 3 seconds
150oF
About 1 ½ seconds
155oF
About 1 second
Table 2
5. New plumbing typically has contamination in the lines. Please flush the system before connection.
B. RELIEF VALVE
The relief valve must comply with the standard for Relief Valves and Automatic Gas Shutoff Devices for Hot Water Supply Systems
(ANSI Z21.22) and/or the standard Temperature, Pressure, Temperature and Pressure Relief Valves and Vacuum Relief Valves,
CAN1-4.4, as well as all local codes. In addition, the relief valve must be rated to the maximum BTU/hr rating of the heater.
The American National Standard (ANSI Z21.10.3) / Canadian Standard (CSA 4.3) do not require a combination temperature and
pressure relief valve for this heater. However, a combination temperature and pressure relief valve may be required by local codes.
Connect discharge piping to safe disposal location. See the following guidelines.
16
NOTE: If a relief valve discharges periodically, this may
be due to thermal expansion in a closed water supply
system. DO NOT PLUG THE RELIEF VALVE. An
expansion tank may be required.
LP-171 Rev. 4.10.14
17
All piping methods shown in this manual use primary/secondary connection to the heater loop. This is to avoid the possibility of noise or
actuator problems in zone valves because of the high-head heater circulator. For other piping methods, consult your local HTP
representative or refer to separate piping details in this manual.
Expansion tanks must be sized according to total system volume. This includes all length of pipe, all fixtures, appliances, etc. Failure to
properly size system expansion could result in wasted time, money, and possible property damage, personal injury, or death.
Undersized expansion tanks cause system water to be lost from relief valve and make-up water to be added through fill valve. Eventual
failure can result due to excessive make-up water addition. SUCH FAILURE IS NOT COVERED BY WARRANTY.
DO NOT install automatic air vents on closed-type expansion tank systems. Air must remain in the system and return to the tank to
provide its air cushion. An automatic air vent would cause air to leave the system, resulting in water-logging the expansion tank.
DO NOT use the heater circulator in any location other than the ones shown in this manual. The heater circulator is selected to ensure
adequate flow through the heater. Failure to do so could result in unreliable performance and nuisance shutdowns from insufficient flow.
C. SEPARATE LOW WATER CUTOFF
A low water cutoff may be required by state and local codes, or by some insurance companies. A low water cutoff is also required if the
heater is installed above the piping level. Check code requirements before installing the heater.
If required:
Use an electrode probe type low water cutoff designed for hydronic installations.
Install in a tee on the supply piping above the heater.
Follow low water cutoff manufacturer’s instructions.
D. BACKFLOW PREVENTER
Use a backflow preventer specifically designed for hydronic heater installations. This valve should be installed on the cold water fill
supply line per local codes. (See piping details at the end of this section.)
E. SYSTEM WATER PIPING METHODS
EXPANSION TANK AND MAKE-UP WATER
1. Ensure expansion tank size will handle heater and system water volume and temperature. Allow 3 gallons for the heater and its
piping.
2. Expansion tank must be located as shown in Piping diagrams, or following recognized design methods. See tank manufacturer’s
instructions for details.
3. Connect the expansion tank to the air separator only if the separator is on the suction side of the circulator. Always install the system
fill connection at the same point as the expansion tank connection to the system.
4. Most chilled water systems are piped using a closed type expansion tank.
DIAPHRAGM (OR BLADDER) EXPANSION TANK
Always install an automatic air vent on top of the air separator to remove residual air from the system.
F. CIRCULATORS
LP-171 Rev. 4.10.14
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The heater should not be operated as a potable hot water heater. Operating this heater as a potable water heater will VOID warranty.
MINIMUM BOILER FLOW RATES
MODEL
MINIMUM FLOW (GPM)
MC-50
3.3
MC-80
5.3
MC-99
7.8
MC-120
8
SIZING SPACE HEAT SYSTEM PIPING
1. See Piping Details in this section. In all diagrams, the space heating system is isolated from the heating loop by the
primary/secondary connection.
2. Size the piping and components in the space heating system using recognized design methods.
G. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE HEATERS
This heater may function in a closed loop 15 psi system. An optional water pressure switch ensures adequate pressure in the system.
The heater will not operate without a minimum of 10 psi water pressure. This assures you that if the system does have a leak, the
heater will lock out (PRO on the display) before it damages the heat exchanger.
The included temperature and pressure gauge allows the user to monitor the system pressure and outlet temperature from the heater.
It is important to note that the heater has a minimal amount of pressure drop that must be calculated when sizing the circulators. Each
installation must also have an air elimination device that will remove air from the system.
Observe minimum 1” clearance around all un-insulated hot water pipes when openings around pipes are not protected by noncombustible materials. On a heater installed above radiation level, some states and local codes require a low water cut off device (See
Part C this section). If the heater supplies hot water to heating coils in air handler units, flow control valves or other devices must be
installed to prevent gravity circulation of heater water in the coils during the cooling cycle. Chilled water medium must be piped in
parallel with the heater.
1. Connect the system return marked “Heater In”.
2. Connect the system supply marked “Heater Out”.
3. Install purge and balance valve or shut off valve and drain on system return to purge air out of each zone.
4. Install a back flow preventer on the cold feed make-up water line.
5. Install a pressure reducing valve on the cold feed make-up water line, (15 psi nominal on the system return). Check temperature and
pressure gauge, which should read minimum pressure of 12 psi.
6. Install a circulator as shown in piping details (this section). Make sure the circulator is properly sized for the system and friction loss.
7. Install an expansion tank on the system supply. Consult the tank manufacturer’s instruction for specific information relating to
expansion tank installation. Size the expansion tank for the required system volume and capacity.
8. Install an air elimination device on the system supply.
9. Install a drain valve at the lowest point of the system. NOTE: The heater cannot be drained completely of water without purging the
unit with an air pressure 15 psi.
10. The safety relief valve is installed at the factory. Pipe the discharge of the safety relief valve to prevent injury in the event of
pressure relief. Pipe the discharge 6” above the drain to a drain. Provide piping that is the same size as the safety relief valve outlet.
Never block the outlet of safety relief valve.
H. CIRCULATOR SIZING
The heat exchanger has a minimum total water volume that must be taken into account when sizing the circulator. These minimum
water volumes are listed in Table 3 below.
Table 3 – Minimum Heat Exchanger Water Volumes
In addition, the heat exchanger has pressure drop which must be considered in your system design. Refer to the graph in Figure 4 for
pressure drop through the heat exchanger for recommended pump selection at a 20∆t design.
LP-171 Rev. 4.10.14
The chart below represents various system temperatures and their respective flows and friction loss through the heater, which will aid
circulator selection.
19
Figure 4 – Pressure Drop Graph and Temperature Rise Chart – LP-171-F NOTE: The recommended circulators are based on 1 gpm per 10,000
btu/hr with 20∆t.
I. ZONING WITH ZONE VALVES
1. Connect heater to system as shown in 1A and 1B in Piping Details when zoning with zone valves. The primary/secondary piping
shown ensures the heater loop will have sufficient flow. It also avoids applying the high head of the heater circulator to the zone valves.
2. Connect DHW (domestic hot water) piping to indirect storage water heater as shown.
J. ZONING WITH CIRCULATORS
1. Connect heater to system when circulator zoning as shown in 1C and 1D in Piping Details when zoning with circulators. The heater
circulator cannot be used for a zone. It must supply only the heater loop.
Install a separate circulator for each zone.
2. Connect DHW (domestic hot water) piping to indirect storage water heater as shown.
K. MULTIPLE HEATERS
1. Connect multiple heaters as shown in 1E and 1F in Piping Details.
2. All piping shown is reverse return to assure balanced flow through the connected heaters.
3. Each connected heater must have its own circulator pump to assure adequate flow.
4. Connect DHW (domestic hot water) piping to indirect storage water heater as shown.
LP-171 Rev. 4.10.14
20
For installations that incorporate standing iron radiation and systems with manual vents at the highest points: Follow the
above section and, starting with the nearest manual vent, open until water flows out. Then close vent. Repeat procedure, working your
way toward furthest air vent. It may be necessary to install a basket strainer in an older system where larger amounts of sediment may
be present. Annual cleaning of the strainer may be necessary.
Use only inhibited propylene glycol solutions, specially formulated for hydronic systems. Ethylene glycol is toxic and can attack gaskets
and seals used in hydronic systems. Glycol mixtures should not exceed 50%.
It is highly recommended that you carefully follow the glycol manufacturer’s concentrations, expansion requirements, and maintenance
recommendations (pH additive breakdown, inhibitor reduction, etc.) You must carefully figure the additional system friction loss, as well
as the reduction in heat transfer coefficients.
L. FILL AND PURGE HEATING SYSTEM
Attach the hose to balance and purge hose connector or drain valve and run hose to nearest drain.
Close the other side of the balance and purge valve or the shut off valve after the drain.
Open first zone balance and purge or drain valve to let water flow out the hose. If zone valves are used, open the valves one
at a time manually. (NOTE: You should check valve manufacturer’s instruction prior to opening valves manually, so as not to
damage the valve.)
Manually operate fill valve regulator. When water runs out of the hose, while it’s connected to the balance and purge valve or
drain you will see a steady stream of water (without bubbles). Close balance and purge valve or drain to stop the water from
flowing. Disconnect the hose and connect it to next zone to be purged.
Repeat this procedure for additional zones (one at time).
Upon completion, make sure that the fill valve is in automatic position and each zone balance and purge or shut off is in an open
position and zone valves are positioned for automatic operation.
1. Glycol for hydronic applications includes inhibitors that prevent it from attacking metallic system components. Make certain that the
system fluid is checked for the correct glycol concentration and inhibitor level.
2. The glycol solution should be tested at least once a year and as recommended by the glycol manufacturer.
3. Anti-freeze solutions expand more than water. For example a 50% by volume solution expands 4.8% in volume for a temperature
increase from 32° F to 180° F, while water expands 3% with the same temperature rise. Allowances must be made for this expansion in
the system design.
4. A 30% mixture of glycol will result in 15% BTU output loss and a 5% increase in head against system circulator.
5. A 50% mixture of glycol will result in 30% BTU output loss and a 50% increase in head against system circulator.
LP-171 Rev. 4.10.14
M. PIPING DETAILS
21
Figure 5
LP-171 Rev. 4.10.14
22
Figure 6
NOTES:
1. This drawing is meant to demonstrate system piping concept only. Installer is responsible for all equipment and detailing required by local codes.
2. All closely spaced tees shall be within 4 pipe diameters center to center spacing.
3. A minimum of 6 pipe diameters of straight pipe shall be installed upstream and downstream of all closely spaced tees.
4. The minimum pipe size for connecting an indirect water heater is 1”.
5. The minimum pipe size for connecting the unit is 1.25”.
6. Circulators are shown with isolation flanges. The alternative is standard flanges with full port ball valves. Purge valves can be used with the circulator
flanges as an alternative.
7. The anti-scald mixing valve is recommended if the DHW temperature is set above the factory setting of 119oF.
8. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
9. Winterization: When winterizing the unit, put a drain valve on both the supply and return between the union and the shut-off connection.
LP-171 Rev. 4.10.14
23
Figure 7
NOTES:
1. This drawing is meant to demonstrate system piping concept only. Installer is responsible for all equipment and detailing required by local codes.
2. All closely spaced tees shall be within 4 pipe diameters center to center spacing.
3. A minimum of 6 pipe diameters of straight pipe shall be installed upstream and downstream of all closely spaced tees.
4. The minimum pipe size for connecting an indirect water heater is 1”.
5. The minimum pipe size for connecting the unit is 1.25”.
6. Circulators are shown with isolation flanges. The alternative is standard flanges with full port ball valves. Purge valves can be used with the circulator
flanges as an alternative.
7. The anti-scald mixing valve is recommended if the DHW temperature is set above the factory setting of 119oF.
8. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
9. Winterization: When winterizing the unit, put a drain valve on both the supply and return between the union and the shut-off connection.
LP-171 Rev. 4.10.14
24
Figure 8
NOTES:
1. This drawing is meant to demonstrate system piping concept only. Installer is responsible for all equipment and detailing required by local codes.
2. All closely spaced tees shall be within 4 pipe diameters center to center spacing.
3. A minimum of 6 pipe diameters of straight pipe shall be installed upstream and downstream of all closely spaced tees.
4. The minimum pipe size for connecting an indirect water heater is 1”.
5. The minimum pipe size for connecting the unit is 1.25”.
6. Circulators are shown with isolation flanges. The alternative is standard flanges with full port ball valves. Purge valves can be used with the circulator
flanges as an alternative.
7. The anti-scald mixing valve is recommended if the DHW temperature is set above the factory setting of 119oF.
8. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
9. Winterization: When winterizing the unit, put a drain valve on both the supply and return between the union and the shut-off connection.
LP-171 Rev. 4.10.14
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