Hydro Smart 115 PLUS User manual

Hydro Smart 115 PLUS Gas Micro Boiler
Installation Manual and Owner’s Guide
If the information in these instructions is not
followed exactly, a re or explosion may result
causing property damage, personal injury or
death.
-Do not store or use gasoline or other ammable
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 electric 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 performed by
a qualied installer, service agency or the gas
supplier.
If you have any questions,
please call or write to:
10725 165th Ave. NW
Elk River, MN 55331
Featuring
• Flow Activated: .75 GPM
• Wall Hung
• Copper Heat Exchanger
• Temperature Range: 99°-140° F
• Freeze Protection
• Power Vent
• CAT III Stainless Steel Venting
• Built in Boiler Remote
• Includes LP Conversion Kit
The Hydro Smart 115 PLUS Gas
Micro Boiler is a compact and powerful
residential unit with a versatile BTU
modulating range.
Do not return to stores. Damages or
repairs call Hydro Smart 763-331-3066
M-F 8 AM - 5 PM Sat 8 AM - Noon
NG/LP
Boiler is set up for
NG, includes LP
Conversion Kit

2
CONTENTS
Installation Manual/Owners Guide
SPECIFICATIONS..............................................................................................4
INTRODUCTION................................................................................................5
SAFETY GUIDELINES.......................................................................................6
INSTALLATION (GENERAL)..............................................................................7
CLEARANCES...................................................................................................9
HIGH ALTITUDE INSTALLATIONS...................................................................10
VENTING INSTRUCTIONS (GENERAL)..........................................................11
GAS SUPPLY & PIPE SIZE..............................................................................13
PRESSURE RELIEF VALVE/ELECTRICAL CONNECTIONS..........................15
APPLICATIONS................................................................................................16
INITIAL OPERATION........................................................................................18
OPERATING SAFETY.......................................................................................19
NORMAL OPERATION.....................................................................................21
TEMPERATURE SETTINGS............................................................................22
FLOW/FREEZE PROTECTION........................................................................24
MAINTENANCE AND SERVICE.......................................................................25
ADDITIONAL FEATURES.................................................................................26
VENTING AND CLEARANCES........................................................................27
ERROR CODES...............................................................................................37
TROUBLESHOOTING.....................................................................................40
COMPONENTS DIAGRAM..............................................................................42
PARTS LIST......................................................................................................46
OUTPUT TEMPERATURE CHART..................................................................48
NOTES.............................................................................................................49

3
Installation Manual
& Owners Guide
CONGRATULATIONS
Congratulations and thank you for choosing our micro boiler. Before use, we
recommend that you read through this installation manual carefully. Keep
this manual for future reference.
If you need an additional manual, contact the manufacturer or your local
distributor. When you call, please tell us the product name and the serial
number of your unit written on the rating plate of the boiler.

4
SPECIFICATIONS
*18-25 PSI is recommended for maximum ow (Space Heating)
**The Manifold Pressure is the factory setting and generally should not need adjustment.
NOTE:
• Check the rating plate to ensure this product matches your specications.
• The manufacture reserves the right to discontinue, or change at any time, specications, or
designs without notice and without incurring obligation.
*When using boiler in-conjunction with Hydro Smart Combi panel, system pressure may be much higher on your domestic
water side. Your space heating side should still reect the recommended 18-25 PSI for system pressure.
Model HS115 PLUS
BTU/h
Natural Gas Input
(Operang Range)
Min.: 15,000
Max.: 140,000
Gas Connecon 3/4" NPT
Supply/Return Connecons 3/4" NPT
Water Pressure* psi
(Mpa) 18-25 PSI (For Radiant Only Systems), Up to 150 with DHW
" W.C.
Natural gas
Inlet Pressure (kPa)
Min. 4.0 (1.00)
Max. 10.5 (2.61)
Weight lbs. (kg) 37.5 (17.0)
Dimensions H20.5 x W13.8 x D9.1 (Inch)
H520 x W351 x D231 (mm)
Ignion Electric Ignion
Electric
Supply VAC / Hz 120 / 60
Consumpon
Operaon W / A 54 / 0.64 79 / 0.99 82 / 1.02
Standby W / A 2 / 0.06 2 / 0.06 3 / 0.07
Freeze-
Protecon W/ A 96 / 0.82 96 / 0.82 97 / 0.82

5
INTRODUCTION
• This manual provides information necessary for the installation, operation, and maintenance of the
boiler.
• The model description is listed on the rating plate which is attached to the side panel of the boiler.
• Please read all instructions completely before installing this product.
• If you have any problems or questions regarding this equipment, consult the manufacturer or its
local representative.
• This equipment is a micro boiler designed to e󰀩ciently supply endless hot water for your needs.
(Radiant Heating, or Domestic Water used in-conjunction with Radiant Heating) See Combi panel
for more information on integrating domestic water with your radiant heating system.
• These boilers are only to be installed indoors.
• The principle behind micro boilers is easy:
*This diagram illustrates micro boiler design concepts only and does not accurately represent the
boilers physical description.
1. Your thermostat indicates a need for heat and turns on the circulator pump(s).
2. Water ows through the boiler.
3. The ow sensor detects the water ow.
4. The computer initiates the fan motor and sends a signal to the igniter to create an ignition spark.
5. The gas ignites and ames appear within the burner chamber.
6. Water circulates through the heat exchanger and then gets hot.
7. Using thermistors to measure temperatures throughout the micro-boiler, the computer modulates
the gas and water valves to ensure proper output water temperature.
8. When your room reaches desired temperature the pumps turn o󰀨 and the boiler shuts down.
Burners
Exhaust vent
Heat exchanger
Gas valves
Fan motor
Flow adjustment valve
Thermistor
Return From Panel Gas inlet
Supply to Panel
Thermistor
Burners
Computer board
Flow sensor
Igniter
Intake vent

6
SAFETY GUIDELINES
SAFETY DEFINITION
Indicates informaon considered important but not hazard related.
GENERAL
WARNING
CAUTION
Indicates an imminently hazardous situaon which, if not avoided, could result
in death or serious injury.
Indicates an imminently hazardous situaon which, if not avoided, could result
in minor or moderate injury.
DANGER
Indicates an imminently hazardous situaon which, if not avoided, will result in
death or serious injury.
WARNING cause severe injury or death.
NOTICE
• The conversion to propane must be done by a qualified service agent or a gas ulity
serviceman in accordance with the gas conversion instrucons and all codes and
requirements of the authority having jurisdicon. Failure to follow instrucons could
result in serious injury or property damage. The qualified agent performing this work
assumes responsibility for this conversion.
• Do not use this appliance if any part has been under water. Immediately contact a
qualified installer or service agency to replace a flooded boiler. Do not aempt
to repair the unit! It must be replaced!
• Do not disconnect the electrical supply if the ambient temperature will drop below
freezing. The Freeze Protecon System only works if the unit has electrical power. The
warranty will not be covered if the heat exchanger is damaged due to freezing.
1. Follow all local codes, or in the absence of local codes, follow the current edion of the Naonal Fuel Gas Code:
ANSI Z223.1/NFPA 54 in the USA or B149.1 Natural Gas and Propane Installaon code in Canada.
2. Properly ground the unit in accordance with all local codes, or in the absence of local codes, with the current
edion of the Naonal Electrical Code: ANSI/NFPA 70 in the USA or CSA standard C22.1 Canadian Electrical
Code Part 1 in Canada.
3. Carefully plan where you intend to install the boiler.Please ensure:
• Your boiler will have enough combuson air and proper venlaon.
• Locate your boiler where water leakage will not damage surrounding areas.
4. Check the rang plate for the correct GAS TYPE, GAS PRESSURE, WATER PRESSURE and ELECTRIC RATING.If this
unit does not match your requirements, do not install and consult with the manufacturer. The boiler is
configured only for use with Natural Gas at the factory. If the appliance is used with propane gas, conversion to
propane gas with an included conversion kit (LP Conversion Kit) is required. The conversion must
be done by a qualified service agent or a gas ulity serviceman in accordance with this instrucon and all codes
and requirements of the authority having jurisdicon. Failure to follow instrucons could result in serious injury
or property damage. The agent performing this work assumes responsibility for this conversion. (Refer to the
gas conversion leaflet.)
5. If any problem should occur, turn offall hot water fixtures and turn offthe gas. Then call a trained technician
or the Gas Company or the manufacturer.
• Water temperatures over 125 °F (52 °C) can cause severe burns instantly or death from
scalding. The water temperature is set at 120 °F (50 °C) from the factory to minimize any
scalding risk. Before bathing or showering, always check the water temperature.
• Do not store or use gasoline or other flammables, vapors, or liquids in the vicinity of this appliance.
• Do not reverse the water and/or gas connecons as this will damage the gas valves and can
DHW Use

7
INSTALLATION
GENERAL
1. Follow all local codes, or in the absence of local codes, follow the current edion of the Naonal Fuel
Gas Code: ANSI Z223.1/NFPA 54 in the USA or B149.1 Natural Gas and Propane Installaon Code in
Canada.
2. All gas boilers require careful and correct installaon to ensure safe and efficient operaon.
This manual must be followed exactly. Read the “Safety Guidelines” secon.
3. The manifold gas pressure is preset at the factory. It is computer controlled and should not need
adjustment.
4. Maintain proper space for servicing. Install the unit so that it can be connected or removed easily.
5. The boiler must be installed in a locaon where the proper amount of combusble air will be
available to it at all mes without obstrucons.
6. The electrical connecon requires a means of disconnecon, to terminate power to the water heater.
This is necessary for servicing and safety purposes.
7. Do not install the unit where the exhaust vent is poinng into any opening in a building or where the
noise may disturb your neighbors. Ensure that the vent terminaon meets the minimum distance
requirements set by code, including minimum clearances from doorways or openings.
8. Parcles from flour, aerosols, and other contaminants may clog the air vent, build up and reduce
the funcons of the rotang fan, cause improper burning of the gas, or cause damage to the water
heater. Regularly ensure that the area around the unit is dust- or debris-free. Regular maintenance is
recommended for these types of environments. Direct Venng is recommended.
9. Venng:
• If the boiler is used as a direct-vent appliance, the unit requires a 3 in. (76 mm)
combusble air supply pipe. The intake pipe must be sealed airght.
• Terminang the venng through a sidewall is recommended for the direct-vent system.
• Running the exhaust vent and the intake pipe parallel is recommended.
• Terminang the exhaust and intake on the same wall/surface is recommended. Terminang in
the same pressure zone allows for pressure balancing, which prevents nuisance shutdowns.
• Only install the boiler in a heated area where below freezing temperatures cannot occur.
The warranty does not cover damage caused by freezing.
• The boiler must be securely mounted to a wall or other suitable structure.

8
WARNING
•Installaon and service must be performed by a qualified installer (for example,
a licensed plumber or gas fier). Otherwise, the warranty will be void.
•The installer (licensed professional) is responsible for the correct installaon of
the boiler and for compliance with all naonal, state / provincial, and local
codes.
•The manufacturer does not recommend installing the boiler in a pit or
locaon where gas and water can accumulate.
• Do not have the vent terminal poinng toward any operang window, door, or
opening into a building.
• Do not install next to any source of airborne debris, such as a clothes dryer, that
can cause debris to be trapped inside the combuson chamber, unless the system
is direct-vented.
•The manufacturer does not suggest installing the boiler in an ac due to
safety issues.If you install the water heater in an ac:
• Make sure the unit will have enough combuson air and proper venlaon.
• Keep the area around the boiler and its terminaon clean. When dust
collects on the flame sensor, the water heater will shut down and produce an
error code.
• Place the unit for easy access for service and maintenance.
• A drain pan, or other means of protecon against water damage, is
recommended to be installed under the boiler in case of leaks. The
manufacturer is not responsible for damage due to water leaks.
CAUTION
•The warranty will not cover damage caused by water quality.
• Only potable water can be used with this boiler.Do not introduce pool
or spa water, or any chemically treated water into the boiler.
• Water hardness levels must not exceed 7 grains per gallon (120 ppm) for
single family domesc applicaons or more than 4 grains per gallon (70 ppm)
for all other types of applicaons. Water hardness leads to scale formaon
and may affect / damage the boiler.Hard water scaling must be
avoided or controlled by proper water treatment.
• Water pH levels must be between 6.5 and 8.5
• Well water must be treated.
• Do not install the unit where water, debris, or flammable vapors may get into the
flue terminal.
•The manufacturer recommends direct venng when the boiler is installed
in beauty salons, dry cleaners or any other locaons in which such chemicals
are present in the air.Some chemicals used in beauty salons or dry cleaners may
affect the flame sensor.In such cases, the boiler may not work properly.
•Although the boiler is designed to operate with minimal sound, the
manufacturer does not recommend installing the unit on a wall adjacent toa
bedroom, or a room that is intended for quiet study or meditaon, etc.
• Locate your boiler close to a drain where water leakage will not do damage to
surrounding areas. As with any water heang appliance, the potenal for leakage
at some me in the life of the product does exist. The manufacturer will not be
responsible for any water damage that may occur.If you install a drain pan under
the unit, ensure that it will not restrict the combuson air flow.

9
CLEARANCES
Top
Back
Side
Side
Front
Model Top Boom Front Back Sides
12 in.
(305 mm)
12 in.
HS115 PLUS (NG/LP) (305 mm)
4 in.**
(102 mm)
1.0 in.
(25 mm)
3 in.
(76 mm)
**24 inches recommended for maintenance.
Installaon
Manual
Qty: 1
LP Conversion Kit
Manifold gasket: 1
Spare Screw : 2

10
Bank of DIP switches
HS115 PLUS Computer board
NOTE: The dark squares indicate the correct DIP switch posions.
Check the elevaon where your boiler is installed. Set your DIP switches according to altude as
shown below.
DIP Switch Sengs
0 to 2,000 .
(0 to 610 m)
(DEFAULT)
2,001 to
3,000 .
(611 to 914 m)
3,001 to
5,000 .
(915 to 1,524 m)
5,001 to
7,500 .
(1,525 to 2,286 m)
7,501 to
10,100 .
(2,287 to 3,078 m)
HS115 PLUS
ON 1 2 3 4 5 6 789 10
OFF
No. 3 : OFF
No. 4 : OFF
No. 5 : OFF
ON 1 2 3 4 5 6 789 10
OFF
No. 3 : OFF
No. 4 : ON
No. 5 : OFF
ON 123456789 10
OFF
No. 3 : OFF
No. 4 : OFF
No. 5 : ON
ON 123456789 10
OFF
No. 3 : OFF
No. 4 : ON
No. 5 : ON
ON 123456789 10
OFF
No. 3 : ON
No. 4 : ON
No. 5 : ON
Altude
DIP switches
HIGH-ALTITUDE INSTALLATIONS
Installaon altude
The maximum cerfied or
allowable installed altude
is 10,100 . (3,078 m)

11
VENTING INSTRUCTIONS
For indoor models
-General-
WARNING
• Improper venng of this appliance can result in excessive levels of carbon
monoxide which can result in severe personal injury or death.
• Improper installaon can cause nausea or asphyxiaon, severe injury or death
from carbon monoxide and flue gases poisoning. Improper installaon will void
product warranty.
CAUTION applicable naonal and local codes.
When installingthe vent system, all applicable naonal and local codes must be
followed. If you install thimbles, fire stops or other protecve devices and they
penetrate any combusble or noncombusble construcon, be sure to follow all
The boiler must be vented in accordance with the secon “Venng of Equipment" of the current
edion of the Naonal Fuel Gas Code: ANSI Z223.1/NFPA 54, as well as applicable local building codes.
The manufacturer recommends NovaVENT™ or Z-Vent® category III, single wall, stainless steel venng.
See "Approved Category III, Single Wall, Stainless Steel Venng and Part Numbers" on the next page.
General rules for air intake:
The boiler can obtain its combuson air from the space that it is installed in or it can be direct
vented.
Direct venng installaon:
• The air intake can use 3" PVC (solid core), CPVC (solid core), ABS, or category III vent.
• Use of cellular core PVC (ASTM F891), cellular core CPVC,or Radel® (polyphenylsulfone) in non-
metallic venng systems is prohibited. Covering non-metallic vent pipe and fings with thermal
insulaon is prohibited.
• Ensure that the installaon locaon has sufficient, clean combuson air. If unsure, direct vent the
boiler or refer to the Combuson Air Supply secon below.
Combuson air from the room:
• Install a 3" elbow into the air intake collar.
General rules for venng water heaters are:
• The maximum length of intake air piping must not exceed 60 . (18.3 m). Deduct 5 . (1.5 m) for
each 90° elbow or 2.5 (0.76 m) for each 45° elbow used in the venng system. Two 45° elbows
when connected together are equivalent to one 90° elbow. Refer to the tables on p. 19.
• When the horizontal air intake exceeds more then 5 ., support the pipe every 3 . with pipe
hangers.
• Vercal air intake pipe must be supported with pipe hangers. Ensure that the weight of the pipe
is not carried by the water heater.
• Place the boiler as close as possible to the vent terminaon.
• The vent collar of the boiler must be fastened directly to an unobstructed vent pipe.
• Do not weld the vent pipe to the boiler’s vent collar.
• Do not cut or alter the shape of the vent collar of the unit.
• The vent must be easily removable from the top of the boiler for normal service and
inspecon of the unit and vent system.
• The boiler vent must not be connected to any other gas appliance or vent stack.
• Avoid using an oversized vent pipe or using extremely long runs of pipe.
• For rooop venng, a rain cap or other form of terminaon that prevents rain water from
entering into the boiler must be installed.
• Do not common vent or connect any vent from other appliances to the boiler vent.

12
General rules for vent terminaons:
• A condensate collector is required for horizontal and/or vercal vent runs exceeding 5 . of
equivalent length (not including sidewall terminatons).
• A backflow preventor should be installed in the exhaust when the heater is installed in climates
subject to freezing temperatures.
WARNING! Do not mix parts or fings of different material types, and do not mix pipe, fings, or
joining methods from different manufacturers. Combuson exhaust can contain carbon monoxide and
must be properly vented outside. Breathing abnormal amounts of carbon monoxide can result in seri-
ous injury or death.
• Avoid locang the boiler vent terminaon near any air intake devices.These fans can
pick up the exhaust flue products from the boiler and return them to the building. This
can create a health hazard.
• Locate the vent terminaon so that it cannot be blocked by any debris, at any me. Most codes
require that the terminaon must be at least 12 in. (305 mm) above grade and ancipated snow
level, but the installer may determine if it should be higher depending on the job site condion
and applicable codes.
• A proper sidewall terminaon is required when the boiler is vented through a sidewall.
• Refer to the following pages for exhaust terminaon and air inlet clearances.

13
-General-
• Minimum and maximum inlet gas pressures:
• Inlet gas pressures that fall outside the range of values listed above may adversely affect the
performance of the water heater. These pressures are measured when the boiler is in full
operaon and when it is in stanby.
• Inlet gas pressure must not exceed the above maximum values; gas pressure above the specified range
will cause dangerous operang condions and damage to the unit.
• Unl tesng of the main gas line supply pressure is completed, ensure the gas line to the boiler
is disconnected to avoid any damage to the boiler.
• If the gas supply pressure to the heater is greater than the specified maximum, a field-supplied
regulator is required. The regulator must lower the gas pressure within the approved range.
• Install the gas regulator according to the manufacturer's instrucons.
• The regulator must be sized for the water heater input and provide the specified pressures that
are listed on the rang plate.
• In the absence of minimum install distance, it is recommended that the gas regulator be installed
no closer than 3 . (1 m) from the boiler's inlet gas connecon.
NOTICE
Gas type Inlet gas pressure
Natural Gas
Propane
Min. 4.0” W.C. (1.00 kPa) – Max. 10.5” W.C. (2.61 kPa)
Size the gas pipe to supply the necessary volume of gas for the boiler. Refer
to and follow the requirements listed in the current edion of ANSI Z223.1/NFPA
54 (USA), B149.1 (Canada), or local codes. Otherwise, flow capabilies and output
temperatures will be limited.
Min. 8.0” W.C. (1.99 kPa) – Max. 14.0” W.C. (3.48 kPa)
1. Install a full port, manual gas shutoffvalve between the boiler and the gas supply line.
2. When the gas connecons are completed, it is necessary to perform a gas leak test either by applying
soapy water to all gas fings and observing for bubbles or by using a gas leak detecon device.
• The boiler and its individual shutoffvalve must be disconnected from the gas supply
piping system during any pressure tesng of that system at test pressures in excess of 1/2 psi
(3.5 kPa).
• The boiler must be isolated from the gas supply piping system by closing its individual
manual shutoffvalve during any pressure tesng of the gas supply piping system at test
pressures equal to or less than 1/2 psi (3.5 kPa).
3. Always purge the gas line of any inert gas, debris, and/or water before connecng to the gas inlet.
WARNING
•Do not use this boiler with any gas other than the one listed on the
rang plate unless the boiler has been properly converted.
•Ensure that any and all gas regulators used are operang properly and
providing gas pressures within the specified range shown below. Excess gas
inlet pressure may cause serious accidents.
•If your boiler needs a gas conversion, refer to the instrucons supplied
with the boiler and included with the conversion components.
GAS SUPPLY AND GAS PIPE SIZING

14
Based on Energy
Content of 1,000
BTU/Cubic :
Divide each
appliance's BTU/h
requirement by
Take into account
the distance the
10' (3.1 m) Length 10' (3.1 m) Length 1,000 BTU/3to get
5' (1.5 m) Length 3/4" Pipe size 15' (4.6 m) Length 1/2" Pipe size the appliance's 3/h
1-1/4" Pipe size AB
1" Pipe size requirement.
gas chart to properly
Gas meter size the line.
5' (1.5 m) Length 10' (3.1 m) Length 15' (4.6 m) Length appliance is from
1-1/4" Pipe size 3/4" Pipe size C1/2" Pipe size the gas meter, then
look in the above
Boiler
199,000 BTU/hDryer
35,000 BTU/h
Furnace
120,000 BTU/h
Range
65,000 BTU/h
For secons of the
gas line supplying gas to more than one appliance (Ex: Point A to Point B), add up the cubic . per hour requirements
of the appliances that are being supplied by that secon, and size to the farthest appliance.
For Example: The secon from A to B supplies gas to the furnace, range and dryer. Adding up the BTU/h requirements
and dividing by 1,000 yields a cubic . per hour requirement of 220 cubic . of gas per hour. The farthest appliance
is the range, which is 50 . (15.2 m) away from the meter. According to the chart above, the 50-. (15.2 m) column
shows that Secon A to B must be 1" in order to supply 220 cubic per hour.
10' (3.1 m) Length
1" Pipe size
elpmaxegnizissaG
(Natural Gas)
Pipe Size Length: . (m)
Diameter:
in.
10'
(3.0)
20'
(6.1)
30'
(9.1)
40'
(12.2)
50'
(15.2)
60'
(18.3)
70'
(21.3)
80'
(24.4)
90'
(27.4)
100'
(30.5)
125'
(38.1)
150'
(45.7)
200'
(61.0)
1/2" 172 118 95 81 72 65 60 56 52 50 44 40 34
3/4" 360 247 199 170 151 137 126 117 110 104 92 83 71
1" 678 466 374 320 284 257 237 220 207 195 173 157 134
1 1/4" 1,309 957 768 657 583 528 486 452 424 400 355 322 275
1 1/2" 2,090 1,430 1,150 985 873 791 728 677 635 600 532 482 412
2" 4,020 2,760 2,220 1,900 1,680 1,520 1,400 1,300 1,220 1,160 1,020 928 794
Unit: Cubic feet per hour
Unit: kBTU per hour
The following tables are from NFPA 54
-Natural Gas Supply Piping-
Maximum delivery Capacity of Cubic Feet of Gas per Hour of IPS Pipe carrying Natural Gas with 0.60 Specific Gravity
Based on Pressure Drop of 0.5" W.C.
Based on Energy Content of 1,000 BTU/Cubic .: The boiler requires 140 Cubic ./hr.
Pipe Size Length: . (m)
Diameter 10'
(3.0)
20'
(6.1)
30'
(9.1)
40'
(12.2)
50'
(15.2)
60'
(18.3)
70'
(21.3)
80'
(24.4)
90'
(27.4)
100'
(30.5)
125'
(38.1)
150'
(45.7)
200'
(61.0)
1/2" 268 184 148 126 112 101 93 87 82 77 68 62 53
3/4" 567 393 315 267 237 217 196 185 173 162 146 132 112
1" 1,071 732 590 504 448 409 378 346 322 307 275 252 213
1 1/4" 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440
1 1/2" 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675
2" 6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496 1,260
-Propane (LP) Supply Piping-
Maximum Capacity of Propane (LP) Based on 11" W.C. supply pressure at a 0.5" W.C. pressure drop

15
-Pressure relief valve- (DHW Applicaons)
The boiler has a high-temperature shutoffswitch built in as a standard safety feature (called a
Hi-Limit switch). Therefore, a “pressure only” relief valve is required.
ELECTRICAL CONNECTIONS
• This unit does not come with an approved pressure relief valve.
• An approved pressure relief valve must be installed on the hot water outlet.
• The pressure relief valve must conform to the current edion of ANSI Z21.22 or CAN 1-4.4 and instal-
laon must follow local codes.
• The discharge capacity must be at least 140,000 BTU/h for DHW applicaons.
• The pressure relief valve must be rated for a maximum of 150 psi (1 MPa).
• The discharge piping for the pressure relief valve must be directed so that the hot water cannot splash
on anyone or on nearby equipment.
• Aach the discharge tube to the pressure relief valve and run the end of the tube to within 6 in.
(152 mm) from the floor. This discharge tube must allow free and complete drainage without any
restricons.
• If the pressure relief valve installed on the water heater discharges periodically, this may be due to a
defecve thermal expansion tank or defecve pressure relief valve.
• The pressure relief valve must be manually operated periodically to check for correct operaon.
WARNING! Hot water will be released. The contact of discharge may cause property damage and/
or bodily harm. Before operang the pressure relief valve manually, check that it will discharge in
a safe place. If water does not flow freely from the end of the discharge pipe, turn the gas supply
OFF and call a qualified person to determine the cause.
•No valve shall be placed between the relief valve and the water heater.
WARNING
• Ensure that circuit power is turned OFF before you complete the following steps.
• Follow the electrical code requirements of the local authority having jurisdicon.
In the absence of such requirements, follow the current edion of the Naonal
Electrical Code ANSI/NFPA 70 in the U.S. or the current edion of CSA C22.1 Canadian
Electrical Code Part 1 in Canada
• When servicing or replacing parts within the water heater, label all wires prior to dis
-
connecon to facilitate an easy and error-free reconnecon. Wiring errors can cause
improper and dangerous operaon. Verify proper operaon aer servicing.
• Failure to follow these instrucons can result in fire, electrical shock, or death.
NOTE: Hydro Smart Radiant Panel systems include a pressure relief valve for the radiant applicaon.

16
APPLICATIONS
Space Heating Applications
• In order to purge air in water pipes within a closed loop system, an air vent,
air separator, and expansion tank should be installed in the system. (Hydro
Smart pre-built space heating panels incorporate all of these features).
• Water temperature over 125° F (52° C) can cause sever burns instantly of
death from scalding.
• Chemicals such as diluted Glycol can be used for radiant oor, Hydro/fan
coil air or Baseboard heating only. The diluted solution of glycol must contain
between 25% and 55% of Glycol. Be aware that in a closed loop system, low
pressure in the heat exchanger can cause low-temperature boiling, resulting
in excessive noise and damage to the micro boiler. Consult with the glycol
maker for specications prior to use.
Hydro Smart Pre-Built Space Heating Panels
Hydro Smart pre-plumbed panels help make space heating easy and reliable. These panels are
professionally engineered and use proven Primary/Secondary hydronic practices. Call Tech Support
(1-763-331-3066) for assistance.
WARNING
HSPS120LT 1 Zone Panel:
For more information on Hydro Smart pre-plumbed panels and zoning options for this boiler please
visit www.hydro-smart.com or call 763-331-3066.
Sample:

17
Dual-purpose hot water heating
(Domestic and Space Heating)
Insert a Hydro Smart Combi Panel to provide potable heated water and Hydronic Heating (with space
heating panel(s)) with one heat source.
The Hydro Smart Combi Panel integrates with a wide variety of boilers and delivers “Priority” potable
heated water with no storage tank and hydronic space heating in a small reliable package.
Follow all local codes, or in the absence of local codes, follow the most recent
edition of the National Standard Code, ANSI Z21.10.3.
For more information on Hydro Smart Combi panels and integrating space heating and domestic
water for this boiler please visit www.hydro-smart.com or call 763-331-3066.
NOTICE

18
INITIAL OPERATION
Operaon (With Radiant & DHW Applicaons)
1.
2.
Once the above checks have been completed, please clean the filter
(Y-Strainer) of any debris.
Fully open the manual water control valve on the water supply line.
3. Open a hot water tap to verify that water is flowing to that tap. Then
close the hot water tap.
4. Fully open the manual gas control valve.
5.
6.
Turn on the 120 VAC, 60 Hz power supply to the water heater.
Now you are ready to enjoy hours of endless hot waterand/or
FOR YOUR SAFETY, READ BEFORE OPERATING
IF YOU SMELL GAS:
supplier’s instrucons.
WARNING
• If you cannot reach your gas supplier, call the fire department.
• Do not try to start the boiler.
• Do not touch any electric switches; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor’s phone. Follow the gas
•Check the GAS and WATER CONNECTIONS for leaks before firing the unit for the first me.
• Open the main gas supply valve to the unit using only your hand to avoid any spark. Never use
tools. If the knob will not turn by hand, do not try to force it; call a qualified service technician.
Forced repair may result in a fire or explosion due to gas leaks.
• Be sure to check for the presence of leaking gas toward the boom of the unit because some
gases are heavier than air and may sele toward the floor.
•Check the GAS PRESSURE
• Do not try to light the burner manually. It is equipped with an electronic ignion device which
automacally lights the burner.
•Check for PROPER VENTING and COMBUSTIBLE AIR to the boiler.
•Purge the GAS and WATER LINESto remove any air pockets.
• Do not use this boiler if any part has been submersed under water. Do not aempt to
repair the unit. It must be replaced. Failure to follow these instrucons could lead to property
damage, personal injury, or loss of life.
For radiant only applicaons, turn up the thermostat to call for heat and iniate flow through the boiler.
radiant heang.

19
OPERATING SAFETY
WARNING:
causing property damage, personal injury or loss of life.
WHAT TO DO IF YOU SMELL GAS
A. This appliance does not have a pilot. It is equipped with an ignition device which automatically
lights the burner. Do not try to light the burner by hand.
B. BEFORE OPERATING smell all around the appliance area for gas. Be sure to smell next to
.
• Do not try to light any appliance.
• Do not touch any electric 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.
C. Use only your hand to turn the gas shutoff valve. Never use tools. If the valve will not turn by
must be replaced!
1. Turn off all electric power to the appliance if service is to be performed.
2. Turn the gas shutoff valve located on the outside of the unit to the closed position.
FOR YOUR SAFETY READ BEFORE OPERATING
OPERATING INSTRUCTIONS
TO TURN OFF GAS TO APPLIANCE
1. STOP! Read the safety information above on this label.
2. Turn off all electric power to the appliance.
3. Do not attempt to light the burner by hand.
4. Turn the gas shutoff valve located on the outside of the unit to the closed position.
5.
safety information above on this label. If you don’t smell gas, go to the next step.
6. Turn the gas shutoff valve located on the outside of the unit to the open position.
7. Turn on all electrical power to the appliance.
8. If the appliance will not operate, follow the instructions in “To Turn Off Gas to Appliance,” and
call your service technician or gas supplier.

20
FLAMMABLES
DANGER
area near the water heater.
Vapors:
1. Far away from heater.
2. In approved containers.
3. Tightly closed and out of reach of children.
4. Water heater has a main burner, which may
vapors.
1. Cannot be seen.
2. Are heavier than air.
3.
4. Can be carried from other rooms to the main
burner by air currents.
A pressure relief valve listed as complying with the standard for Relief Valve and Automatic Gas Shutoff
Devices for Hot Water Supply System, ANSI Z21.22
・
CSA 4.4, shall be installed at the time of installation
relief devices for safety operation of the water heater. The relief valve must not be removed or plugged.
No valve shall be placed between the relief valve and the water heater. The relief from the discharge of
the pressure relief valve shall be disposed of in a suitable place where it will cause no damage. Also, there
.
See Installation Manual heading “PRESSURE RELIEF VALVES” for installation and maintenance of relief
valve discharge line and other safety precautions.
used
will reduce, but not eliminate the risk of vapors being ignited by the
main burner.
Flammable Vapors
Read and follow water heater warnings and instructions. If the owner’s
manual is missing, contact the retailer or manufacturer.
1. Water temperature over 125°F (52°C) can cause severe burns instantly or death from
scalds.
2. Children, disabled and elderly are at highest risk of being scalded.
3. Feel water before bathing or showering.
4. Temperature limiting valves are available. See manual.
BURN
BRÛLURE
HOHOTT
5. The outlet temperature of the water heater is set at 120°F (50°C).If you require water temperatures
below this setting, follow the instruction manual.
6. Use this heater at your own risk. Test the water before bathing or showering. Do not leave children or
temperature limiting valves that are available.
CHAUDECHAUDECHAUDE
HOT
DANGER