Mod Con MODCON500, MODCON700 Installation Manual

Installation

Start-Up

Maintenance

Parts

Warranty

MODCON500 / 700 / 850 VWH Models*

Mod Con

Volume Water Heaters

*“VWH” Denotes Hot Water Supply Boiler “LP” Denotes Propane Gas Operation “HL” Denotes Installed High and Low Gas Pressure Switches “WL” Denotes Installed High Temperature Water Limit

This Manual For Use With Boilers Manufactured After

August 13, 2013

Heat Exchanger Bears the ASME “H” Stamp

This manual must only be used by a qualied installer / service technician. Read all instructions in this manual before installing. Perform steps in the given order. Failure to do so could result in substantial property damage, severe personal injury, or death.

Improper installation, adjustment, alteration, service, or maintenance could void product warranty and cause property damage, severe personal injury, or death.

HTP reserves the right to make product changes or updates without notice and will not be held liable for typographical errors in literature.

The surfaces of these products contacted by potable (consumable) water contain less than 0.25% lead by weight as required by the Safe Drinking Water Act, Section 1417.

NOTE TO CONSUMER: PLEASE KEEP ALL INSTRUCTIONS FOR FUTURE REFERENCE.

272 Duchaine Blvd. New Bedford, MA 02745 www.htproducts.com

LP-446-r4 Rev. 10.12.16

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 APPLIANCE.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch.

• Do not use any phone in your building.

• Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.

• If you cannot reach your gas supplier, call the re department. Installation and service must be provided by a qualied

installer, service agency, or the gas supplier.

LP-446-r4 Rev. 10.12.16

The following dened 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 serious personal injury or death.

WARNING indicates a potentially hazardous situation which, if not avoided, could result in personal injury or death.

CAUTION indicates a potentially hazardous situation which, if not avoided, may result in moderate or minor personal injury.

CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property damage.

NOTICE is used to address practices not related to personal injury.

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 in this system, and additional publications including the Code for the Installation of Heat Producing

Appliances and National Fuel Gas Code - ANSI Z223.1 (latest

versions), 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 AHJ may be a federal, state, local government, or individual such as a re chief, re marshal, chief of a re prevention bureau, labor department or health department, building ocial 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 ocer or departmental ocial may be the AHJ.

NOTE: HTP, Inc. reserves the right to modify product technical specications and components without prior notice.

For the Installer

This boiler must be installed by qualied and licensed personnel. The installer should be guided by the instructions furnished with the boiler, and by 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, latest version.

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.

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 specied in ANSI Z21.13 - latest edition.

LP-446-r4 Rev. 10.12.16

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 o 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. The temperature control system integrated into the 926 control provided with this heating appliance complies with the requirements of CSD-1 Section CW-400 as a temperature operation control. The control monitors the temperature dierence between the inlet and the outlet sensor, which is aected by boiler water ow. If this temperature dierence exceeds 55°F (typically because of low water ow or very low heat load), the control will reduce the maximum fan speed. If the temperature dierence exceeds 60°F, the control will eectively sense there is little or no water ow or heat load and shut the boiler down. The controller will restart automatically once the temperature dierence has dropped below 55°F and the minimum o time (anti-cycle time) has expired. In addition, if the control senses that the outlet water temperature has reached 210°F, the boiler is put into a hard lockout and requires manual reset to restart.

Table of Contents

Part 1 - General Safety Information 5

A. Improper Combustion 5 B. Gas 5 C. When Servicing the Water Heating System 5 D. Boiler Water 6 E. Freeze Protection 6 F. High Elevation Installations 6 G. Water Temperature Adjustment 6

Part 2 - Before You Start 7

A. What’s in the Box 8 B. How the Boiler Operates 8 C. Optional Equipment 8

Part 3 - Prepare the Boiler 9

A. Locating the Boiler 9 B. Flooring 10 C. Leveling 10 D. Clearances for Service Access 10 E. Residential Garage and Closet Installations 11 F. Exhaust Vent and Intake Pipe 11

1. Direct Vent of Exhaust and Intake 12

2. Indoor Combustion Air in Conned or Unconned Space 12 G. Prevent Combustion Air Contamination 12 H. Removing a Boiler from a Common Vent System 12 I. Water Chemistry Requirements* 13

Part 4 - Piping 14

A. General Plumbing Information 15 B. Relief Valve 15 C. Backow Preventer 15 D. Potable Expansion Tank 15 E. Circulators 16 F. Scalding 16 G. High Velocity Circulator Pump 16 H. Water Chemistry 18

J. Applications 19

Part 5 - Venting and Condensate Removal 22

A. General 22

B. Approved Materials for Exhaust Vent and Intake Pipe 23

C. Additional Requirements for Installation in Canada 23 D. Exhaust Vent and Intake Pipe Location 24 E. Exhaust Vent and Intake Pipe Sizing 25 F. Longer Vent Runs 25 G. Exhaust Vent and Intake Pipe Installation 25 H. Applications 26

1. Direct Vent Installation of Exhaust and Intake 26

2. Room and Indoor Combustion Ventilation Requirements 29

I. Condensate Removal System 30

Part 6 - Wiring 31

A. Installation Must Comply With 31 B. Field Wiring Terminations 31 C. Field Wiring 31 D. Line Voltage Wiring for Standard Boiler 32 E. Alarm Connections 32 F. Low Voltage Connections for Standard Boiler 33 G. Tank Sensor or Mechanical Control 33 H. System / Pipe Sensor 33 I. Optional 0-10 Volt Building Control Signal 33 J. Optional High Gas Pressure Switch 33 K. Optional Low Gas Pressure Switch 33 L. Flow Switch 33 M. Wiring of Cascade System Communication Bus 33 N. Cascade Master Pump and Sensor Wiring 34 O. Cascade Follower Pump and Sensor Wiring 34

Part 7 - Gas Connections 37

A. Gas Piping 37 B. Gas Table 38 C. Check Inlet Gas Pressure 38 D. Boiler Gas Valve 39

Part 8 - Start-Up Preparation 40

A. Check / Control Water Chemistry 40 B. Check for Gas Leaks 40 C. Condensate Removal 40 D. Final Checks Before Starting Boiler 40 E. Setting Up a Single Boiler 40 F. Setting Up a Cascaded System 41 G. Lockout Condition 41 H. Cascade System Programming 41

Part 9 - Start-Up Procedure 42

A. Control Overview 42 B. Navigation of the Display 42 C. Operating Instructions 43 D. Programming Boiler Settings 43 E. Programming the System Setting 44 F. System Setting Program Navigation 44 G. Resetting the Maintenance Schedule 46

Part 10 - Start-Up Procedures for the Installer 46

A. Boiler Control Status Menu 46 B. Cascade Menu 47 C. Boiler Test Mode 48

Part 11 - Troubleshooting 49

A. Boiler Error and Fault Codes 49 B. Boiler Error 49 C. Boiler Fault 49

LP-446-r4 Rev. 10.12.16

D. User Interface Display 50

Part 12 - Maintenance 55

A. Procedures 55 B. Combustion Chamber Coil Cleaning Instructions 55 C. Cleaning Water Side of Heat Exchanger 56

Part 13 - Installation Checklist 61 Part 14 - Maintenance Report 61

Limited Warranty 65 Maintenance Notes 67 Customer Installation Record Form 68

This boiler has been designed to heat potable water ONLY. Using this boiler to heat non-potable uid WILL VOID product warranty, and could result in property damage, personal injury, or death.

Altering any HTP, Inc. boiler with parts not manufactured by HTP, Inc. WILL INSTANTLY VOID the boiler warranty and could result in property damage, personal injury, or death.

Part 1 - General Safety Information

This boiler is approved for indoor installations only and is not intended for use as a pool heater. Clearance to combustible materials: 0” top, bottom, sides, and back. Left side has all boiler mechanical connections. Boiler must have room for service: 24” front is minimum recommended service clearance. (A combustible door or removable panel is acceptable front clearance.) This boiler has been approved for closet installation and installation on combustible ooring. Do not install directly on carpeting. Install the boiler in a location where temperature and pressure relief valve discharge or a leak will not result in damage to the surrounding area. If such a location is not available, install an auxiliary catch pan. Use only Category IV vent systems.

Installer - Read all instructions in this manual before installing. Perform steps in the given order.

User - This manual is for use only by a qualied heating installer / service technician. Have this boiler serviced / inspected annually by a qualied service technician.

FAILURE TO ADHERE TO THE GUIDELINES ON THIS PAGE CAN RESULT IN SUBSTANTIAL PROPERTY DAMAGE, SEVERE PERSONAL INJURY, OR DEATH.

NOTE: If the boiler is exposed to the following, do not

operate. Immediately call a qualied service technician.

1. Fire

2. Damage

3. Water Failure to follow this information could result in property damage, severe personal injury, or death.

DO NOT USE THIS BOILER IF ANY PART HAS BEEN SUBMERGED IN WATER. Immediately call a qualied

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 re 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 ood or submersion is considered an Act of God, and IS NOT covered under product warranty. NOTE: Obey all local codes. Obtain all applicable permits before installing the boiler.

NOTE: Install all system components and piping in such a manner that does not reduce the performance of any re rated assembly.

Do not use this boiler for anything other than its intended purpose (as described in this manual). Doing so could result in property damage and WILL VOID product warranty. High heat sources (sources generating heat 100oF / 37oC or greater, such as stove pipes, space heaters, etc.) may damage plastic components of the boiler as well as plastic vent pipe materials. Such damages ARE NOT covered by warranty. It is recommended to keep a minimum clearance of 8” from high heat sources. Observe heat source manufacturer instructions, as well as local, state, provincial, and national codes, laws, regulations and ordinances when installing this boiler and related components near high heat sources. Due to low water content of the boiler, improperly sizing the boiler in regard to potable water heating load will result in excessive boiler 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.

A. Improper Combustion

Do not obstruct the ow of combustion and ventilating air. Adequate air is necessary for safe operation. Failure to keep the exhaust vent and combustion air intake clear of ice, snow, or other debris could result in property damage, serious personal injury, or death.

B. Gas

Should overheating or gas supply fail to shut o, turn o the manual gas control valve to the boiler.

C. When Servicing the Water Heating System

Be sure to disconnect electrical power before opening boiler cabinet or performing service. Failure to do so could result in electrical shock, property damage, serious personal injury, or death.

To avoid electric shock, disconnect electrical supply before performing maintenance.

NOTE: When inquiring about service or troubleshooting, reference the model and serial numbers from the boiler rating label.

To avoid severe burns, allow boiler and associated equipment to cool before servicing.

LP-446-r4 Rev. 10.12.16

D. Boiler Water

Do not use petroleum-based cleaning or sealing compounds in a water heating 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”. Damage to the boiler, substantial property damage, and/or serious personal injury may result.

E. Freeze Protection

NOTE: Consider piping and installation when determining boiler location.

Failure of the boiler due to freeze related damage IS NOT covered by product warranty.

NEVER use any toxic chemical, including automotive, standard glycol antifreeze, or ethylene glycol made for hydronic (nonpotable) systems. These chemicals can attack gaskets and seals in water systems, are poisonous if consumed, and can cause personal injury or death.

UNCRATING THE BOILER - Any claims for damage or shortage in shipment must be led immediately against the transportation company by the consignee.

F. High Elevation Installations

Natural gas at high elevation might contain less heating value than typical 1,000 BTU/cu ft and therefore can cause improper air / gas mix leading to improper combustion. For natural gas installations above 3,000 ft, call your gas provider to determine the heating value of the supplied natural gas.

G. Water Temperature Adjustment

If the boiler is going to have a set temperature above 120oF, you must use an ASSE 1017 rated mixing valve to avoid severe burns or death from scalding temperatures.

Households with small children, disabled, or elderly persons may require a 120oF or lower temperature setting to prevent severe personal injury or death due to scalding.

Approximate Time / Temperature Relationships in Scalds

120

F More than 5 minutes

F 1 1/2 to 2 minutes

125

F About 30 seconds

130

F About 10 seconds

135

F Less than 5 seconds

140

F Less than 3 seconds

145

F About 1 1/2 seconds

150

F About 1 second

155

Table 1 - Approximate Time / Temperature Relationships in Scalds

LP-446-r4 Rev. 10.12.16

Part 2 - Before You Start

CAUTION

VWH units must be connected to a storage tank. You must not have a direct connection of the potable water system into the heat exchanger. This could cause ow issues, short cycling, and an increase of mineral build-up in the unit. This system is designed to have incoming potable water ow through the storage tank rst, then through the heat exchanger. Failure to connect the VWH boiler to a storage tank of the minimum size requirements (119 gallons for a single 500VWH; 175 gallons for a single 700/850VWH) will result in property damage and/or premature boiler failure. Damages resulting from incorrect installation or from use of products not approved by HTP, Inc. ARE NOT covered by warranty.

500VWH 700VWH 850VWH

First

Hour

∆T

(Delta T)

(

100

110

120

130

140

Table 2 - VWH Ratings with Storage Tanks - NOTE: Gallons Per Hour Does Not Take a Storage Tank into Account

Min Tank Size (Gal.) = Required Flow (GPM) X 10

Gallons

Per Hour

1414 859 883 894 1980 1206 1217 1260 2404 1449 1459 1502

1131 872 902 915 1584 1225 1238 1292 1923 1467 1481 1534

943 884 920 937 1320 1244 1260 1324 1602 1486 1502 1566

808 897 939 958 1131 1262 1281 1356 1374 1505 1524 1599

707 910 958 979 990 1281 1303 1388 1202 1524 1545 1631

628 923 977 1001 880 1300 1324 1420 1068 1542 1566 1663

566 935 995 1022 792 1319 1345 1453 961 1561 1588 1695

514 948 1014 1044 720 1337 1367 1485 874 1580 1609 1727

471 961 1033 1065 660 1356 1388 1517 801 1599 1631 1759

435 974 1052 1087 609 1375 1410 1549 740 1617 1652 1791

404 986 1070 1108 566 1394 1431 1581 687 1636 1674 1824

Rating

119

Gallon

Tank

Contact HTP for Available

First

Hour

Rating

175

Gallon

Tank

Storage Tanks

First

Hour

Rating

200

Gallon

Tank

Gallons

Per Hour

First

Hour

Rating

119

Gallon

Tank

Contact HTP for Available

First

Hour

Rating

175

Gallon

Tank

Storage Tanks

First

Hour

Rating

200

Gallon

Tank

Gallons

Per Hour

First

Hour

Rating

175

Gallon

Tank

Contact HTP for Available

First

Hour

Rating

200

Gallon

Tank

Storage Tanks

First

Hour

Rating

300

Gallon

Tank

Mixing Factor (Mf) = VWH Outlet Temp - Inlet Temp 70

First Hour Rating = Total VWH Output X VWH Eciency + .75 X Total Storage X M

[ (VWH Outlet Temp - Inlet Temp) X 8.31

Example:

2 500VWH Boilers - Total Output = 1,000,000 BTU @ 94% Eciency VWH Outlet Temp = 140oF - Inlet Temp = 40oF 2 Storage Tanks (119 Gallons Each) =Total Storage = 238 Gallons

Mixing Factor (Mf) = 140 - 40 70

First Hour Rating = 1,000,000 X .94 + .75 X 238 X 1.43

[(140 - 40) X 8.31

First Hour Rating = 940,000 + 179 X 1.43

[ 831

First Hour Rating = [1,131 + 179] X 1.43

First Hour Rating = 1,310 X 1.43

First Hour Rating = 1,873 Gallons

= 1.43

]

LP-446-r4 Rev. 10.12.16

A. What’s in the Box

Remove all sides of the shipping crate of the boiler. Components included with the boiler:

• Temperature and Pressure Gauge

• Pressure Relief Valve

• Three (3) Stainless Steel Screens

• Supply and Return Thermistors

• Wiring Harness

• Flow Switch and Fitting

• System/Pipe Sensor

• Installation Manual and Warranty

• User’s Information Manual

• CSD-1 Form

• H-3 Data Sheet

B. How the Boiler Operates

VWH® condensing technology intelligently delivers large amounts of hot water while maximizing eciency. Outlined below are the features of the system and how they operate:

Stainless Steel Heat Exchanger

The highly ecient stainless steel heat exchanger is designed to use the cold water return from the storage tank and extract the last bit of heat before it is exhausted.

Modulating Combustion System

The combustion system modulates the output of the burner during operation to match system demand and achieve the control set point while in operation. The set point can change by internal or external signals to enhance the overall performance of the system.

Control

The integrated control system monitors the system and regulates fan speed to control boiler output. This allows the boiler to deliver only the amount of heat energy required and nothing more. The control can regulate the output of multiple boilers through its cascade system function. The cascade system is capable of connecting up to eight boilers together in such a way that they function as one boiler system. This allows for greater turn down ratios and provides systematic control of the multiple boilers in an installation to minimize downtime and maximize eciency. The cascade system works by establishing one boiler as the master and the other connected boilers as followers. The master boiler requires a sensor to provide feedback on set point temperature in order to adjust heating input from the connected boilers. Each cascaded boiler will have its own pump to provide maximum ow and control heat exchanger ow rate.

Text Display and Operational LED Light Indicators

The display allows the user to change system parameters and monitor system outputs.

Gas Valve

Senses suction from the blower, allowing gas to ow only if powered and combustion air is owing.

Integrated Venturi (500 Models) or Swirl Plate (700/850 Models)

Controls air and gas ow into the burner.

Burner

The high grade stainless steel burner uses premixed air and gas to provide a wide range of ring rates.

Spark Ignition

The burner is ignited by applying high voltage through the

system spark electrode. The spark from the electrode ignites mixed gas o of the burner.

Supply Water Temperature Sensor

This sensor monitors the boiler outlet water temperature (System Supply). The control adjusts boiler ring rate so the supply temperature will match the boiler set point.

Return Water Temperature Sensor

This sensor monitors boiler return water temperature (System Return).

Temperature and Pressure Gauge

Allows the user to monitor system temperature and pressure.

Electrical eld connections with terminal strips

The electrical cover allows easy access to the clearly marked line voltage and low voltage terminal strips to facilitate wiring the boiler.

Condensate Collection System

This boiler is a high eciency appliance and will produce condensate. The condensate collection system has a oat switch which monitors condensate level and prevents condensate from backing up into the combustion system. Inside the collection system is a built in trap which seals the combustion system from the connected drain. This condensate should be neutralized to avoid damage to the drainage system or piping.

Flow Protection

The supplied ow switch is designed to protect the boiler during low ow conditions. The boiler control also monitors ow through the heat exchanger by monitoring the return and supply sensors and will shut down the burner before overheating occurs.

System Pipe Sensor

This sensor is designed to be used in a cascade system. When placed on the supply line feeding the storage tank, the system pipe sensor measures the temperature of return water and communicates with the control system to modulate the ring rate of the connected boilers. NOTE: When using a system sensor, pipe insulation must be wrapped around it to improve temperature measurement accuracy and increase overall system eciency.

0-10 Volt Input

Allows the installer to connect a BMS (Building Management System) to control the boiler.

Indirect Tank Sensor (optional)

Monitors storage tank temperature.

C. Optional Equipment

Optional equipment available from HTP (and Part #):

• Indirect Tank Sensor (7250P-325)

• 4” Stainless Steel Vent Termination Kit (V2000)

• 6” Stainless Steel Vent Termination Kit (V3000)

• High and Low Gas Pressure Switch Kit with Manual

Reset (7350P-600)

• UL 353 Compliant Low Water Cut-O Interface Kit with Manual Reset (7350P-601)

• Alarm System (to monitor any failure) (7350P-602)

• PC Connection Kit (7250P-320)

• Condensate Neutralizer (7350P-611)

• Caster Kit (7350p-604)

• Glass-Lined Storage Tanks (GL-119, GL-175)

• Stainless Steel Storage Tank (SSU-119CB)

LP-446-r4 Rev. 10.12.16

Part 3 - Prepare the Boiler

Remove all sides of the shipping crate to allow the boiler to be moved into its installation location. Pick the boiler up by the lifting rings to avoid damage to the boiler enclosure. Use either solid 3/4” diameter black iron pipe or lifting straps to lift the boiler o its shipping crate. The boiler is heavy. At least two individuals are needed to properly handle the boiler. The boiler is also equipped with leveling feet that can be used to level the boiler properly on an uneven location surface. If surface ooring is rough, take care when moving the boiler into position, as catching the leveling feet could damage the boiler.

1. Installation Area (Mechanical Room) Operating Conditions

• Ensure ambient temperatures are higher than 32

F / 0oC

and lower than 104oF / 40oC

• Prevent the air from becoming contaminated by the products, places, and conditions listed in this manual

• Avoid continuously high levels of humidity

• Never close existing ventilation openings

• Ensure a minimum 1” clearance around hot water and

exhaust vent pipes

• NOTE: To prevent condensing in the fan, it is recommended to avoid prolonged exposure to temperatures below 45

Figure 1 - Lifting the Boiler

COLD WEATHER HANDLING - If the boiler has been stored in

a very cold location (BELOW 0oF) before installation, handle with care until the components come to room temperature. Failure to do so could result in damage to the boiler. Carefully consider installation when determining boiler location. Please read the entire manual before attempting installation. Failure to properly take factors such as boiler venting, piping, condensate removal, and wiring into account before installation could result in wasted time, money, and possible property damage and personal injury.

A. Locating the Boiler

This boiler is certied for indoor use only. DO NOT INSTALL OUTDOORS. Outdoor installations ARE NOT covered by warranty. Failure to install the boiler indoors could result in property damage, severe personal injury, or death. Incorrect ambient conditions can lead to damage to the heating system and put safe operation at risk. Ensure that the 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 boiler or components due to incorrect operating conditions IS NOT covered by product warranty.

This boiler has a condensate disposal system that may freeze if exposed to sustained temperatures below 32oF. Precautions should be taken to protect the condensate trap and drain lines from sustained freezing conditions. Failure to take precautions could result in property damage, severe personal injury, or death.

2. Check for nearby connections to:

• System water piping

• Venting connections

• Gas supply piping

• Electrical power

• Condensate drain

3. Check area around boiler. Remove any combustible materials, gasoline, and other ammable liquids.

Failure to keep the boiler area clear and free of combustible materials, liquids, and vapors can result in substantial property damage, severe personal injury, or death.

LP-446-r4 Rev. 10.12.16

The service life of the boiler’s exposed metallic surfaces, such as the casing, as well as internal surfaces, such as the heat exchanger, are directly inuenced 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 boiler components. In these environments, boilers must not be installed using direct vent systems which draw outdoor air for combustion. Such boilers must be installed using room air for combustion. Indoor air will have a much lower relative humidity, and hence potential corrosion will be minimized. High heat sources (generating heat 100oF / 37oC or greater, such as boiler ue pipes, space heaters, etc.) may damage plastic components of the boiler as well as plastic vent pipe materials. Such damages ARE NOT covered by warranty. It is recommended to keep a minimum clearance of 8” from high heat sources. Observe heat source manufacturer instructions, as well as local, state, provincial, and national codes, laws, regulations, and ordinances when installing this boiler and related components near high heat sources. Locate the boiler where any leakage from the relief valve, related piping, tank, or connections will not result in damage to surrounding areas or lower oors of the building. The boiler should be located near a oor drain or installed in a drain pan. Leakage damages ARE NOT covered by warranty. Failure of the boiler or components due to incorrect operating conditions IS NOT covered by product warranty.

4. Gas control system components must be protected from dripping water during operation and service.

5. If the boiler is to replace an existing boiler, check for and correct any existing system problems, such as:

• System leaks

• Location that could cause the system and boiler to freeze

and leak

• Incorrectly sized expansion tank

6. Clean and ush system when reinstalling a boiler.

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 boiler model and serial number.

Assure that the oor and structure of the installation location are sucient to support the full installed weight of the boiler, including water content of the heat exchanger and related piping. Failure to ensure the oor and structure of the installation location are structurally sound before installation of the boiler can result in structural failure, substantial property damage, severe personal injury, or death.

C. Leveling

In order for the condensate to properly ow out of the collection system, the area where you locate the boiler must be level. Location must also fully support the weight of the lled boiler.

Figure 2 - Correct and Incorrect Leveling

D. Clearances for Service Access

NOTE: If you do not provide the minimum clearances shown in Figure 3 it might not be possible to service the boiler without removing it from the space.

NOTE: A combustible door or removable panel is acceptable front clearance.

Use extreme care not to drop the boiler or cause bodily injury while lifting the boiler.

Gas conversion should be performed BEFORE the boiler is installed. Carefully follow the gas conversion instructions when performing the conversion.

Failure to follow these instructions could result in property damage, severe personal injury, or death.

B. Flooring

This boiler is approved for installation on combustible ooring, but must never be installed on carpeting. Installing this boiler on carpeting could result in re, property damage, severe personal injury, or death.

LP-446-r4 Rev. 10.12.16

The space must be provided with combustion / ventilation air openings correctly sized for all other appliances located in the same space as the boiler. The boiler cover must be securely fastened to prevent the boiler from drawing air from the boiler room. This is particularly important if the boiler 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.

This boiler must be installed upright in the vertical position as described in this manual. DO NOT attempt to install this boiler in any other orientation. Doing so will result in improper boiler operation and property damage, and could result in serious personal injury or death.

All boilers eventually leak. It is recommended to install a catch pan beneath the boiler. This catch pan should be sized with a maximum depth of 2”, and a minimum diameter 2” greater than the diameter of the boiler. The catch pan should empty into an open drain line. This drain line should be 3/4” ID minimum, piped to an open drain. Failure to follow these instructions could result in property damage. Such damages ARE NOT covered by product warranty.

F. Exhaust Vent and Intake Pipe

The boiler 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.

NOTE: The venting options described here (and further detailed in the Venting section, this manual) are the lone venting options approved for this boiler. Failure to vent the boiler in accordance with the provided venting instructions will void the warranty.

Failure to vent the boiler properly will result in serious personal injury or death.

Do not attempt to vent this boiler by any means other than those described in this manual. Doing so will void the warranty and may result in severe personal injury or death. Vents must be properly supported. Boiler exhaust and intake connections are not designed to carry heavy weight. Vent support brackets must be within 1’ of the boiler and the balance at 4’ intervals. Boiler must be readily accessible for visual inspection for rst 3’ from the boiler. Failure to properly support vents could result in property damage, severe personal injury, or death. The exhaust discharged by this boiler may be very hot. Avoid touching or other direct contact with the exhaust gases of the vent termination assembly. Doing so could result in severe personal injury or death.

Figure 3 - Recommended Service Clearances

E. Residential Garage and Closet Installations

Check with your local Authority Having Jurisdiction for requirements when installing the boiler in a garage or closet. Please read the entire manual before attempting installation. Failure to properly take factors such as venting, piping, condensate removal, and wiring into account before installation could result in wasted time, money, and possible property damage and personal injury.

Precautions

If the boiler is located in a residential garage, per ANSI Z223.1:

• Install the boiler burner and ignition devices a minimum of 18” above the oor of the garage. This will ensure the burner and ignition devices are well o the oor.

• When raising the boiler ensure the entire bottom and fully lled weight of the boiler are fully supported.

• Locate or protect the boiler so it cannot be damaged by a moving vehicle.

The space must be provided with correctly sized combustion/ ventilation air openings for all other appliances located in the space with the boiler. For power venting installations using room air for combustion, refer to the venting section, this manual, for descriptions of conned and unconned spaces. Do not install the boiler in an attic. Failure to comply with these warnings could result in substantial property damage, severe personal injury, or death.

LP-446-r4 Rev. 10.12.16

1. Direct Vent of Exhaust and Intake

If installing a direct vent option, combustion air must be drawn from the outdoors directly into the boiler intake and exhaust must terminate outdoors. There are three basic direct vent options detailed in this manual: 1. Side Wall Venting, 2. Roof Venting, and 3. Unbalanced Venting. Be sure to locate the boiler such that the exhaust vent and intake piping can be routed through the building and properly terminated. Dierent vent terminals can be used to simplify and eliminate multiple penetrations in the building structure (see Optional Equipment in Venting Section). The exhaust vent and intake piping lengths, routing, and termination methods must all comply with the methods and limits given in the Venting Section, this manual. When installing a combustion air intake from outdoors, care must be taken to utilize uncontaminated combustion air. To

prevent combustion air contamination, see Table 3.

2. Indoor Combustion Air in Conned or Unconned Space

This boiler requires fresh, uncontaminated air for safe operation and must be installed in a mechanical room where there is adequate combustion and ventilating air. NOTE: To prevent

combustion air contamination, see Table 3.

Combustion air from the indoor space can be used if the space has adequate area or when air is provided through a duct or louver to supply sucient combustion air based on the boiler input. Never obstruct the supply of combustion air to the boiler. If the boiler is installed in areas where indoor air is contaminated (see Table 3) it is imperative that the boiler be installed as direct vent so that all combustion air is taken directly from the outdoors into the boiler intake connection. Unconned space is space with volume greater than 50 cubic feet per 1,000 BTU/hr (4.8 cubic meters per kW) of the total input rating of all fuel-burning appliances installed in that space. Rooms connected directly to this space through openings not furnished with doors are considered part of the space. See Venting Section for details. Conned space is space with volume less than 50 cubic feet per 1,000 BTU/hr (4.8 cubic meters per kW) of the total input rating of all fuel-burning appliances installed in that space. Rooms connected directly to this space through openings not furnished with doors are considered part of the space. When drawing combustion air from inside a conventionally constructed building to a conned space, such space should be provided with two permanent openings: one located 6” (15 cm) below the space ceiling, the other 6” (15cm) above the space oor. Each opening should have a free area of one square inch

per 1,000 BTU/hr (22cm

/kW) of the total input of all appliances in the space, but not less than 100 square inches (645cm2). If the conned space is within a building of tight construction, air for combustion must be obtained from the outdoors as outlined in the Venting section of this manual.

Failure to provide an adequate supply of fresh combustion air can cause poisonous ue gases to enter the living space, resulting in severe personal injury or death. To prevent combustion air contamination, see Table 3.

G. Prevent Combustion Air Contamination

Install intake air piping for the boiler as described in the Venting Section, this manual. Do not terminate exhaust in locations that can allow contamination of intake air.

Ensure that the intake air will not contain any of the contaminants in Table 3. Contaminated air will damage the boiler, resulting in possible substantial property damage, severe personal injury, or death. For example, do not pipe intake air near a swimming pool or laundry facilities. These areas always contain contaminants.

Products to Avoid

Spray cans containing uorocarbons

Permanent wave solutions Swimming pools

Chlorinated waxes / cleaners Metal fabrication plants

Chlorine-based swimming pool chemicals

Calcium chloride used for thawing Refrigeration repair shops

Sodium chloride used for water softening

Refrigerant leaks Auto body shops

Paint or varnish removers Plastic manufacturing plants

Hydrochloric or Muriatic acid

Cements and glues New building construction

Antistatic fabric softeners used in clothes dryers

Chlorine-type bleaches, laundry detergents, and cleaning solvents

Adhesives used to fasten building products

Table 3 - Products and Areas Likely to Have Contaminants

Areas Likely to Have

Contaminants

Dry cleaning / laundry areas

and establishments

Beauty shops

Photo processing plants

Furniture renishing areas

and establishments

Remodeling areas

Garages and workshops

NOTE: DAMAGE TO THE BOILER CAUSED BY EXPOSURE TO CORROSIVE VAPORS IS NOT COVERED BY WARRANTY. (Refer to the limited warranty for complete

terms and conditions.)

H. Removing a Boiler from a Common Vent System

When drawing combustion air from the outside into the mechanical room, care must be taken to provide adequate freeze protection.

LP-446-r4 Rev. 10.12.16

Do not install the boiler into a common vent with any other appliance. This will cause ue gas spillage or appliance malfunction, resulting in possible substantial property damage, severe personal injury, or death.

Failure to follow all instructions can result in ue gas spillage and carbon monoxide emissions, causing severe personal injury or death.

When removing an existing boiler, follow the steps below.

1. Seal any unused openings in the common venting system.

2. Visually inspect the venting system for proper size and horizontal pitch to determine if there is blockage, leakage, corrosion, or other deciencies that could cause an unsafe condition.

3. If practical, close all building doors, windows, and doors between the space in which the boiler remains connected to the common venting system 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 replace 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 ame of a match or candle or smoke from a cigarette.

6. After it has been determined that each appliance remaining connected to the common venting system properly vents when tested as outlined, return doors, windows, exhaust fans, replace dampers, and any other gas burning appliances 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 of ANSI Z223.1.

I. Water Chemistry Requirements*

Chemical imbalance of the water supply may aect eciency and cause severe damage to the boiler and associated equipment. HTP recommends having water quality professionally analyzed to determine whether it is necessary to install a water softener. It is important that the water chemistry on both the domestic hot water and central heating sides are checked before installing the boiler, as water quality will aect the reliability of the system. In addition, operating temperatures above 140oF will cause the boiler to operate continuously, accelerating the build-up of lime scale and possibly shortening the service life of the boiler. Failure of a boiler due to lime scale build-up, low pH, or other chemical imbalance IS NOT covered by the warranty.

• Sodium less than 20 mGL

• Water pH between 6.0 and 8.0

• Maintain water pH between 6.0 and 8.0. Check with

litmus paper or have it chemically analyzed by water treatment company.

• If the pH diers from above, consult local water treatment for treatment needed.

• Hardness less than 7 grains

• Consult local water treatment companies for unusually

hard water areas (above 7 grains hardness).

• Chlorine concentration less than 100 ppm

• Using chlorinated fresh water should be acceptable as

levels are typically less than 5 ppm.

• Do not connect the boiler to directly heat swimming pool or spa water.

• Do not ll boiler or operate with water containing chlorine in excess of 100 ppm.

*NOTE: It is recommended to clean the heat exchanger at least once a year to prevent lime scale buildup. To clean the heat exchanger, follow the maintenance procedure in this manual.

Hardness: Less than 7 grains Chloride levels: Less than 100 ppm pH levels: 6 - 8 TDS: Less than 2000 ppm Sodium: Less than 20 mGL

Figure 4 - CO Warning Label

LP-446-r4 Rev. 10.12.16

Figure 5 - Boiler Dimensions - NOTE: All Dimensions Are Approximate - VWH in Model Number Denotes Volume Water Heater Model

Part 4 - Piping

Failure to follow the instructions in this section WILL VOID the warranty and may result in property damage, severe personal injury, or death.

LP-446-r4 Rev. 10.12.16

Dielectric unions or galvanized steel ttings must not be used in a system with this boiler. Doing so WILL VOID the warranty. Use only copper, brass, or stainless steel ttings. Teon thread sealant must be used on all connections. DO NOT pipe this boiler with black iron, galvanized steel, steel, or lead pipe. Doing so will result in premature product failure and property damage, and WILL VOID the warranty.

Plumbing of this product should only be done by a qualied, licensed plumber in accordance with all local plumbing codes. The boiler is designed to be connected to a storage tank to supply domestic hot water. HTP oers 119 and 175 gallon size storage tanks in either stainless steel or glass-lined construction. These storage tanks will be directly connected to the boiler supply and return connection.

VWH units must be connected to a storage tank. Failure to connect the VWH boiler to a storage tank of the minimum size requirements (119 gallons for a single 500VWH; 175 gallons for a single 700/850VWH) will result in property damage and/ or premature boiler failure. Damages resulting from incorrect installation or from use of products not approved by HTP, Inc. ARE NOT covered by warranty.

A. General Plumbing Information

The building piping system must meet or exceed the the piping requirements in this manual.

The 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 level in the heat exchanger. Some codes/jurisdictions may require additional external controls.. Use two wrenches when tightening water piping at boiler. Use one wrench to prevent the boiler return or supply line from turning. Failure to prevent piping connections from turning could cause damage to boiler components.

NOTE: The addition of a high temperature limiting device is important if the boiler is to be connected to a domestic hot water system. Connect the cold water supply to both the storage bottom port and the supply side of the boiler (shown in Applications, this manual). It is important that you install a ow check on the supply line of the boiler BEFORE connecting the feed line to the storage tank. This allows the cold feed to ow through the storage tank rst. It is recommended that you install shut o valves on the cold feed line for future ease of service. If there is a back ow preventer or any type of no return valve in the system, then you must install an additional tee for a suitable potable hot water expansion tank. Connect the storage tank return line to the return connection located on the boiler (shown in Applications, this manual). Then connect the storage tank hot water outlet to the hot water plumbing lines.

B. Relief Valve

Connect discharge piping to a safe disposal location following the guidelines below.

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 oor 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 valve may be installed between the relief valve and boiler or in the discharge line. Do not plug or place any obstruction in the discharge line.

• Test the operation of the relief valve after lling 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 T&P valve at least once annually to ensure the waterway is clear. If valve does not operate, turn the boiler “o” and call a plumber immediately.

• Take care whenever operating relief valve to avoid scalding injury or property damage.

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.

Do not thread a cap or plug into the relief valve or relief valve line under any circumstances! Explosion and property damage, serious injury, or death may result.

RE-INSPECTION OF T&P RELIEF VALVES: T&P valves should be inspected AT LEAST ONCE EVERY THREE YEARS, and replaced if necessary, by a licensed plumbing

contractor or qualied service technician to ensure that the product has not been aected by corrosive water conditions and to ensure that the valve and discharge line have not been altered or tampered with illegally. Certain naturally occuring conditions may corrode the valve and its components over time, rendering the valve inoperative. Such conditions can only be detected if the valve and its components are physically removed and inspected. Do not attempt to conduct an inspection on your own. Contact your plumbing contractor for a re-inspection to assure continued safety.

FAILURE TO RE-INSPECT THE T&P VALVE AS DIRECTED COULD RESULT IN UNSAFE TEMPERATURE AND/OR PRESSURE BUILD-UP WHICH CAN RESULT IN PROPERTY DAMAGE, SERIOUS PERSONAL INJURY, OR DEATH.

C. Backow Preventer

Use a backow preventer specically designed for boiler installations. This valve should be installed on the cold water ll supply line per local codes.

D. Potable Expansion Tank

A potable hot water expansion tank is required to oset heated water expansion. In most city plumbing systems, the water meter has a no return or back ow device built into the system to prevent back owing of water into city mains. Some local codes require back ow preventers on all incoming water supplies. The hot water expansion tank must be listed

LP-446-r4 Rev. 10.12.16

for potable water use. The expansion tank should be located on the cold inlet piping close to the boiler.

Expansion Tank and Make-Up Water

1. Ensure that the expansion tank is sized to correctly handle boiler and system water volume and temperature.

Expansion tanks must be sized according to total system volume. This includes all length of pipe, all xtures, boilers, etc. Failure to properly size for system expansion could result in wasted time, money, possible property damage, serious injury, or death.

Undersized expansion tanks cause system water to be lost from the relief valve, causing make-up water to be added. Eventual boiler 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 an air cushion. An automatic air vent would cause air to leave the system, resulting in improper operation of the expansion tank.

The expansion tank must be suitable for hot potable water systems.

Expansion Tank Sizing*

VWH Model Heat Exchanger Volume (Gallons)

500 4.2

700/850 5.8

Table 5 - *Add Required Storage Tank Gallon Size to Heat Exchanger Volume - 119 and 175 Gallon Tanks Available

2. The expansion tank must be located as shown in Applications, this manual, or following recognized design methods. See expansion tank manufacturer’s instructions for details.

E. Circulators

Every VWH system requires special attention to circulator size to overcome pressure drop through the boiler and its related piping. All circulators installed on the VWH system must be designed for potable water installations. Boiler pressure drop is detailed in this manual.

Water temperature above 140oF requires the circulator to run continuously. Water hardness must be between 5 and 7 grains. Hardness above 7 grains will damage the heat exchanger and shorten the service life of the boiler. DO NOT use the boiler circulator in any location other than the ones shown in this manual. The boiler circulator location is selected to ensure adequate ow through the boiler. Failure to comply with this caution could result in unreliable performance and nuisance shutdowns from insucient ow.

F. Scalding

This boiler can deliver scalding water at any faucet in the system. Be careful whenever using hot water to avoid scalding injury. Certain appliances such as dishwashers and automatic clothes washers may require increased water temperatures. By setting the thermostat on this boiler to obtain the increased water temperature required by these appliances you may create the potential for scald injury.

To protect against injury, install a mixing valve in the water system. This valve will reduce point of use discharge temperatures by mixing cold and hot water in branch supply lines. Such valves are available from your local plumbing supplier.

Table 4 details the relationship of water temperature and time with regard to scald injury and may

be used as a guide in

determining the safest water temperature for your applications.

The risk of scalding increases when raising tank temperature. Use a water tempering or mixing valve when raising tank temperature to lessen the chance of scalds. Consult codes for conformance. Failure to install a temperature limiting or mixing valve and follow these instructions could result in property damage, severe personal injury, or death due to scalds.

Approximate Time / Temperature Relationships in Scalds

120

F More than 5 minutes

F 1 1/2 to 2 minutes

125

F About 30 seconds

130

F About 10 seconds

135

F Less than 5 seconds

140

F Less than 3 seconds

145

F About 1 1/2 seconds

150

F About 1 second

155

Table 4 - Approximate Time / Temperature Relationships in Scalds

G. High Velocity Circulator Pump

Every VWH system requires special attention to pump size in order to overcome pressure drop through the boiler and its related piping. All circulators installed on the VWH system must be designed for a potable water system. In addition, the heat exchanger has a minimum total water volume that must be taken into account when sizing the circulator. Minimum ow rates are listed in the table below.

Minimum Boiler Flow Rates

VWH Model Minimum Flow (GPM)

500 33

700/850 54

Table 6 - Minimum Flow Rates

LP-446-r4 Rev. 10.12.16

500 Model 700/850 Models

Table 7 - Heat Exchanger Pressure Drop

The chart below represents various system design temperature rise through the boiler along with respective ows and friction loss. This is provided to aid in circulator selection.

System Temperature Rise Chart

20°Δt 25°Δt 30°Δt

Model Friction Ft Flow Rate (GPM) Friction Ft Flow Rate (GPM) Friction Ft Flow Rate (GPM)

500 19’ 50 11’ 40 8’ 33

700/850 35’ 85 26’ 65 18’ 54

Table 8 - Temperature Rise, Friction Feet, and Flow Rate

Table 9 - Multiple Boiler Manifold Piping

LP-446-r4 Rev. 10.12.16

H. Water Chemistry

Water Hardness

Water hardness is mainly due to the presence of calcium and magnesium salts dissolved in the water. The concentration of these salts is expressed in mg/L, ppm or grains per gallon, as a measure of relative hardness of water. Grains per gallon is the common reference measurement used in the U.S. water heater industry. Hardness expressed as mg/L or ppm may be divided by 17.1 to convert to grains per gallon. Water may be classied as very soft, slightly hard, moderately hard, or hard based on its hardness number. The minerals in the water precipitate out when the water is heated and cause accelerated lime and scale accumulation on a heat transfer surface. If the hardness of the water exceeds the maximum level of 7 grains per gallon, water should be softened to a hardness level no lower than 5 grains per gallon. Water softened as low as 0 to 1 grain per gallon may be under-saturated with respect to calcium carbonate, resulting in water that is aggressive and corrosive.

pH of Water

pH is a measure of relative acidity, neutrality or alkalinity. Dissolved minerals and gases aect water pH. The pH scale ranges from 0 to 14. Water with a pH of 7.0 is considered neutral. Water with a pH lower than 7 is considered acidic. Water pH higher than 7 is considered alkaline. A neutral pH (around 7) is desirable for most potable water applications. Corrosion damage and boiler failures resulting from water pH levels of lower than 6 or higher than 8 ARE NOT covered by the warranty. The ideal pH range for water used in a storage tank or a water heater system is 7.2 to 7.8.

Total Dissolved Solids

Total Dissolved Solids (TDS) is a measurement of all minerals and solids dissolved in a water sample. The concentration of total dissolved solids is usually expressed in parts per million (ppm). Water with a high TDS concentration will greatly accelerate lime and scale formation in the hot water system. Most high TDS concentrations precipitate out of the water when heated. This can generate a scale accumulation on the heat transfer surface that will greatly reduce the service life of a boiler. This scale accumulation can also impede the ability of the heat exchanger to transfer heat into the water. A heat exchanger damaged or blocked by lime/scale accumulation must be replaced. The manufacturer of the boiler has no control of water quality, especially TDS levels in your system. Total dissolved solids in excess of 2,000 ppm will accelerate lime and scale formation

in the heat exchanger. Heat exchanger failure due to total dissolved solids in excess of 2,000 ppm is a non-warrantable condition. Failure of a boiler due to lime scale build up on the heating surface IS NOT covered by the warranty.

Hardness: Less than 7 grains Chloride levels: Less than 100 ppm pH levels: 6-8 TDS: Less than 2000 ppm Sodium: Less than 20 mGL *NOTE: It is recommended you clean heat exchanger at

least once a year to prevent lime scale buildup. Follow the maintenance procedure in the Maintenance Section of this manual to clean the heat exchanger

Piping components Water heating system piping

System piping MUST be sized per technical pipe requirements listed in this manual. Reducing pipe size can restrict ow rate through the boiler, causing inadvertent short cycling and poor system performance.

Check valves

Field supplied. Check valves are recommended for installation as shown in Piping Details.

Boiler isolation valves

Field supplied. Full port ball valves are required. Failure to use full port ball valves could result in a restricted ow rate through the boiler.

Anti-scald mixing valve

Field supplied. A thermostatic mixing valve is recommended when storing domestic hot water above 115°F.

Unions

Field supplied: Recommended for unit serviceability. DO NOT USE DIELECTRIC UNIONS! ONLY BRASS, COPPER, OR STAINLESS STEEL.

Pressure relief valve

Factory supplied on VWH. The pressure relief valve is sized to ASME specications. Storage tank may require additional relief valves depending on local codes.

LP-446-r4 Rev. 10.12.16

Storage Tank

System / Pipe Sensor

Used if sensor cannot be placed at tank

(Important to note that pumps must be wired to run continuously to operate in this configuration)

Indirect / Tank Sensor

Preferred Location

I. Applications

System / Pipe Sensor

Used if sensor cannot be placed on tank

(Important to note that pumps must be wired to run continuously to operate in this configuration)

in this configuration)

Storage Tank

Figure 6 - Piping Legend Figure 7 - VWH Boiler with Storage Tank FIGURE NOTES:

1. This drawing is meant to show system piping concept only.

Installer

is responsible for all equipment & detailing required by local codes.

2. Boiler circulator must be rated for open loop application. Do not use cast-iron circulators.

3. Boiler circulator(s) operate continuously.

4. The minimum pipe size for connecting a storage tank is 1 1/2”.

5. The minimum pipe size for connecting a boiler is 2”. When sizing and installing a multiple boiler system, see Multiple Boiler Manifold Piping Chart, this manual.

6. All pumps are shown with isolation anges or full port ball valves for isolation. The alternative is standard anges with full port ball valves and a

Figure 8 - VWH Boiler with Two Storage Tanks

separate ow check valve.

7. Install a minimum of 12 diameters of straight pipe upstream of all circulators and check valves.

8. Install vacuum relief valve in accordance with local code requirements.

9. Multiple boilers and storage tanks shall be installed with reverse return piping (as shown).

10. Expansion tank must be rated for use with potable water.

11. Use either indirect/tank sensor or system/pipe sensor mounted on common return to the boiler.

12. Aquastat or system/pipe sensor connects to DHW sensor input on boiler.

13. The minimum storage tank size for a 500VWH is 119 gallons. The minimum storage tank size for a 700/850VWH is 175 gallons.

An ASSE 1017 thermostatic mixing valve is recommended on all tanks if the hot water temperature leaving the tank is above 119oF. Failure to do so could result in substantial property damage, serious injury, or death. The piping will not support the weight of the circulators. Refer to the circulator manufacturer’s instructions to properly support the circulator. Failure to comply with these instructions could result in property damage, severe personal injury, or death.

LP-446-r4 Rev. 10.12.16

Storage Tank

System / Pipe Sensor

Used if sensor cannot be place on tank

(Important to note that pumps must be wired to run continuously to operate in this configuration)

Required System /

Pipe

Sensor

System / Pipe Sensor Used if sensor cannot be placed on tank

(Important to note that pumps must be wired to run continuously to operate in this configuration)

Storage Tank

FIGURE NOTES:

1. This drawing is meant to show system piping concept only.

Installer is responsible for all equipment & detailing required by local codes.

2. Boiler circulator must be rated for open loop application. Do not use cast-iron circulators.

3. Boiler circulator(s) operate continuously.

4. The minimum pipe size for connecting a storage tank is 1 1/2”.

5. The minimum pipe size for connecting a boiler is 2”. When sizing and installing a multiple boiler system, see Multiple Boiler Manifold Piping Chart, this manual.

6. All pumps are shown with isolation anges or full port ball valves for isolation. The alternative is standard anges with full port ball valves and a separate ow check valve.

7. Install a minimum of 12 diameters of straight pipe upstream of all circulators and check valves.

8. Install vacuum relief valve in accordance with local code requirements.

9. Multiple boilers and storage tanks shall be installed with reverse return piping (as shown).

10. Expansion tank must be rated for use with potable water.

11. Use either indirect/tank sensor or system/pipe sensor mounted on common return to the boiler.

12. Wire the tank or system/pipe sensor to the DHW sensor terminals input on the follower boiler addressed as #1.

13. Wire the tank or system / pipe sensor connected to the DHW sensor terminals on the follower boiler addressed as #1.

14. The system / pipe sensor must be placed on common piping to the tank as close to the tank as possible.

15. The system / pipe sensor is wired to the system sensor terminals on the master boiler.

16. The minimum storage tank size for a 500VWH is 119 gallons. The minimum storage tank size for a 700/850VWH is 175 gallons.

Figure 9 - Two VWH Boilers with Storage Tank

Figure 10 - Two Stacked VWH Boilers with Storage Tank

LP-446-r4 Rev. 10.12.16

required

system / pipe

sensor

System / Pipe Sensor

Used if sensor cannot be placed on tank

(Important to note that pumps must be wired to run continuously to operate in this configuration)

this configuration)

Storage Tank

Figure 11 - Two Stacked VWH Boilers with Two Storage Tanks

Storage Tank

Figure 12 - Three VWH Boilers with Two Storage Tanks FIGURE NOTES: