Evo HW 79 Wiring diagram

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
EVO DUO
300,000 BTU/hr
399,999 BTU/hr
630,000 BTU/hr
EVO MICRO
80,000 BTU/hr
136,000 BTU/hr
180,000 BTU/hr
199,000 BTU/hr
INNOVA TIVE CONDENSING TECHNOLOGY
By Hamilton Engineering, Inc.
INNOVA TIVE CONDENSING TECHNOLOGY
By Hamilton Engineering, Inc.
Installing, Operating & Maintaining
EVO 79 - 599 HIGH EFFICIENCY
WATER HEATERS AND HEATING BOILERS
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 electrical switch
• Do not use any phone in your building
Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier
instructions. If you can not reach your gas
supplier, call the re department.
If the information in this manual

explosion may result causing
property damage, personal
injury or death.
WARNING
New York Massachusetts SCAQMD CEC Listed
MEA 425-05-E Boilers: G1-06-06-24A Compliant Rule1146.2 California Energy Commission
Heaters: G1-06-06-24B
ANSI STD Z21-13/Z21.13A
Certied to CSA 4.9-2004
ANSI STD Z21.10.3/Z21.10.3.b
Certied to CSA 4.1-2004, add.A,B
WARNING
These appliances MUST be installed by a properly licensed individual in the City and State which the unit is
being installed. All start up adjustments and subsequent service work must be done by a similarly licensed
contractor or a factory trained service individual. Failure to comply could result in loss of warranty and or
severe personal injury, death and or substantial property damage. These instructions are required to be
kept with the appliance on the left side, in the pocket provided.
EVO DUO
300,000 BTU/hr
399,000 BTU/hr
630,000 BTU/hr
EVO DUO
300,000 BTU/hr
399,999 BTU/hr
630,000 BTU/hr
EVO MICRO
80,000 BTU/hr
136,000 BTU/hr
180,000 BTU/hr
199,000 BTU/hr
INNOVA TIVE CONDENSING TECHNOLOGY
By Hamilton Engineering, Inc.
INNOVA TIVE CONDENSING TECHNOLOGY
By Hamilton Engineering, Inc.
EVO MICRO
80,000 BTU/hr
136,000 BTU/hr
180,000 BTU/hr
199,000 BTU/hr

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
USING THIS MANUAL
USING THIS MANUAL
Throughout this manual you will see these
special attention boxes similar to this one,
which are intended to supplement the
instructions and make special notice of
potential hazards. These categories are in the
judgement of Hamilton Engineering, Inc.
SPECIAL ATTENTION BOXES
Indicates a condition or hazard which
WILL cause severe personal injury,
death, or major property damage.
DANGER
Indicates a condition or hazard which
WILL cause severe personal injury,
death, or major property damage.
CAUTION
Indicates a condition or hazard which
WILL cause severe personal injury,
death, or major property damage.
WARNING
WARNING
• THE VENT SYSTEM MUST BE 2 PIPE SEALED COMBUSTION CATEGORY IV ONLY, PVC
SCH 40 OR CPVC SCH 40 OR 80 OR AL 29-4C STAINLESS VENTING FOR ALL MODELS.
• THIS HEATER INSTALLATION MUST CONFORM TO THE LATEST EDITION OF THE
“NATIONAL FUEL GAS CODE” ANSI Z223.1 NEPA 54 AND/OR CAN/CGAB149
INSTALLATION CODES. STATE AND LOCAL CODES MIGHT ALSO APPLY TO
INSTALLATION.
• WHERE REQUIRED BY THE AUTHORITY HAVING JURISDICTION, THE INSTALLATION
MUST CONFORM TO THE STANDARDS FOR CONTROLS AND SAFETY DEVICES FOR
AUTOMATICALLY FIRED HEATERS, ANSI/ASME HEATER AND PRESSURE VESSEL CODE,
SECTION IV, ALONG WITH CSD-1.
• THE HEATER, GAS PIPING, WATER PIPING, VENTING AND ELECTRICAL MUST BE
INSTALLED BY TRAINED & QUALIFIED PERSONNEL FAMILIAR WITH INSTALLATION
PRACTICES, LOCAL CODE, AND LICENSING REQUIREMENTS.
• IF THE INFORMATION IN THESE INSTRUCTIONS ARE NOT FOLLOWED EXACTLY, A FIRE
OR EXPLOSION MAY RESULT, CAUSING PROPERTY DAMAGE, PERSONAL INJURY, OR
DEATH.
• DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND LIQUIDS IN
THE VICINITY OR THIS OR ANY OTHER APPLIANCE.
Page 2 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
TABLE OF CONTENTS
TABLE OF CONTENTS
Part 6 . . . . . . . . . . . . . . . . . . . 23-25
START UP PROCEDURES
A Items to be checked before
lighting the EVO 23
B Lighting Instructions 23-24
C Operating Instructions 24
D Adjusting the Temperature
on the EVO Display 24
E Sequence of Operation 24-25
Part 7 . . . . . . . . . . . . . . . . . . . 25-32
SERVICING
A Servicing the EVO 25
B Placing EVO into Normal Operation 25
C Soft Lockout Codes 26
D Hard Lockout Codes 26-27
E Fault Causes 28-31
F To Turn Off Gas to Appliance 31
G Pump & Wiring Control 31
H Temperature Sensor Reading
Instructions 32
I EVO Sensor Resistance Table 32
Part 8 . . . . . . . . . . . . . . . . . . . 33-48
MAINTENANCE & SPEC. INSTALLATION REQ.
A Maintenance Procedures 33
B Annual Inspection 33
C Condensate Cleaning Instructions 34
D Combustion Chamber
Coil Cleaning Instructions 34-35
E EVO Controls 35-36
F Installation at High Altitudes 36
G Coil Scaling Prevention Feature
(E-6 error codes) 36
H Water Heater Operating Sample 37
I EVO MICRO Parts Breakdown 38-39
J EVO DUO Parts Breakdown 40-41
K Wiring Diagrams 42-47
L Installation Requirements
(Massachusetts) 48
Part 1 . . . . . . . . . . . . . . . . . . . . . 4–7
GENERAL INFORMATION
A How It Operates 4
B EVO Dimensions 5-6
C Pre-installation Requirements 6-7
D Pressure Relief Valve 7
Part 2 . . . . . . . . . . . . . . . . . . . . . 8-9
ELECTRICAL
A Electrical Connection 8
B Internal Wiring Connection 8-9
Part 3 . . . . . . . . . . . . . . . . . . .10–14
GAS CONNECTION
A Gas Connection 10
B Gas Piping 10
C Gas Tables 11
D Gas Valve Set Up 11-12
E Setting Maximum Load 12-13
F Setting Minimum Load 13
G Gas Conversion 13
H Gas Valve Replacement 14
Part 4 . . . . . . . . . . . . . . . . . . . 14-20
VENTING
A Approved Venting Materials 14-15
B Venting the EVO 15-18
C Inlet Air Vent 19
D Venting Runs Exceeding Maximum
Combined Length 19
E Heater Removal from a
Common Vent System 19-20
F Condensate Requirements 20
Part 5 . . . . . . . . . . . . . . . . . . . 20-22
PIPING
A Hydronic Heating Boiler Piping 20-21
B Fill & Purge Heating System 21
C Removing Air from Heat Exchanger 21
D Water Heating Piping 22
Page 3 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GENERAL INFORMATION
PART 1. GENERAL INFORMATION
A. HOW IT OPERATES
The EVO product line is an extremely high efciency water heating product, requiring special venting and
condensate removal precautions. Failure to follow all of the instructions contained in this manual may cause
premature product failure that may not be covered under warranty.
This appliance has built-in freeze protection, automatically activating the circulation pump when the internal
water temperature drops below 41°F. If the internal water temperature drops to 37°F, a burn cycle will be initiated
and will shut down as soon as the supply water temperature has reached 50°F. Power must be left on for this
function to operate.
The appliance’s primary controller (FMT 914) operates all functions of needed control and safety. It contains
sophisticated logic that allows it to operate at very precise temperatures while minimizing burner on/off cycling.
When multiple units are operated as a Cascade to handle a common load, the control contains the ability to
control all of the units as efciently as one. Cascade operation is a factory-installed and programmed option,
requiring a eld wiring connection between appliances for operation.
Looking at the controls on the front of the appliance,
1) POWER on/off switch
2) SETPOINT knob, temperature control (and fan speed control knob during service mode)
3) TEMPERATURE setpoint display
a. Temperature in °F, corresponding to the SETPOINT knob
b. Display will always read temperature setpoint unless there is a fault code displayed.
c. Cascade indicator light, found in the lower right hand corner of the Temperature display. This dot will
be ashing when this appliance is part of a properly-connected, commonly-controlled group of EVO
products and reading temperature sensors.
d. Display code, not ashing indicates a Soft Lockout
e. When this display is ashing a code, the appliance is in a Hard Lockout and the reset must be
pushed to re-start the appliance.
4) Green indicating light labeled BURNER ON; when lit, the burner is ring.
5) RESET button, used as described in 3e above, as well as to view sensors and set altitude
(see pages 32 & 26 respectively for details).
6) SERVICE port, used for connecting a computer to the appliance to download the service fault history, as
well as factory setting of control board parameters. There is a service button located just below the
service port that must be pressed with a pointed object to get to the service mode.
Page 4 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GENERAL INFORMATION
B. EVO DIMENSIONS
Model
199
399
599
F (FPT)
1.5"
2.0"
2.0"
1.0"
G
0.75"
0.75"
1.0"
0.75"
H (MPT)
1.5"
1.5"
1.5"
1.0"
Width
16"
19"
19"
19"
Height
20.5"
33"
35"
33"
Depth
12"
19"
26.5"
19"
D
5"
3"
3"
4"
E
3"
3"
4"
5"
Right-hand view
SERVICE
RESET
LO
TEMPERATURE
CH
- +
Front-hand view
Condensate waste
Condensate trap cleaning point
Gas (G)
Condensate trap cleaning point
Gas (G)
Outlet (F)
Relief Valve Location
Inlet (H)
Air in Exhaust out
Outlet (F)
Air in (D)Exhaust out (E)
Inlet (H)
Air Vent
Height
79-129 1.0"0.75"1.0"16"20.5"12"3"3"
299 1.5"0.75"1.5"19"33"19"3"3"
179-199.1
(FIGURE 1-1)
EVO DIMENSIONS
HW 79
HW 129
HW 179
HW 199.1
HW 199
HW 299
HW 399
HW 599
Model
80,000
136,300
186,000
199,999
199,999
300,000
399,999
630,000
Input
BTU/hr
77,600
132,890
181,002
193,999
193,999
291,000
387,999
611,100
Water Heater*
Output
BTU/hr
74,800
127,441
168,300
186,999
186,999
280,500
373,999
589,050
Boiler**
Output
BTU/hr
93
160
217
233
233
360
466
734
GPH*
Recovery
@100°F T
116
199
272
291
291
450
582
917
GPH*
Recovery
@80°F T
155
265
362
388
600
600
776
1223
GPH*
Recovery
@60°F T
77 lbs.
77 lbs.
91 lbs.
91 lbs.
112 lbs.
111 lbs.
194 lbs.
234 lbs.
Shipping
Weight
(TABLE 1-1) EVO INFORMATION
*At 97% thermal efciency with 86oF incoming water to heat exchanger
**At 95% thermal efciency with 140oF incoming water to heat exchanger
Page 5 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GENERAL INFORMATION
C. PRE INSTALLATION REQUIREMENTS
The EVO MICRO is designed to be wall mounted using the supplied mounting
bracket or a factory supplied frame. Details are shown in Figure 1-3. The EVO
DUO must be installed using a factory supplied frame or rack system. The EVO
DUO is substantially heavier than traditional wall mounted appliances,
caution must be exercised when choosing a mounting surface if the leg
portion of a rack system is not used. Please see uninstalled unit weights
on page 5. It can be installed in alcoves, basements, utility rooms as well as
standard equipment rooms. Choose a location for your EVO, centralized to
the piping system, along with consideration for Electrical (Part 2, Page 8), Gas
Connection (Part 3, Page 10), Venting (Part 4, Page 14), and Condensate Drain
(Part 4, Section F, Page 20).
The EVO heat exchanger must be level as installed, and the mounting sur-
face must be designed to support the weight (see previous page, Table 1-1 for
weights). Be sure the appliance is adequately secured to the mounting surface.
The front cover is secured by a threaded screw and two clasp style latches; it
can only be installed one way. When removing the front cover of the EVO
unit, you must make sure all electric power to the appliance is turned
off. Then remove the screw at the bottom of the panel, undo the latches and
remove the cover (see Figure 1-4 on the next page).
If the EVO is set up for liqueed petroleum (LP) gas, some geographic areas follow the Uniform Mechanical
Code, section 304.6, “Liqueed petroleum gas burning appliances shall not be installed in a pit, basement or
similar location where heavier-than-air gas might collect. Appliances so fueled shall not be installed in a below
grade under-oor space or basement unless such location is provided with an approved means for removal
of unburned gas.”
(FIGURE 1-3)
EVO MOUNTING DETAIL
(FIGURE 1-2) EVO CLEARANCES
RECOMMENDED SERVICE CLEARANCES
(NOTE: The EVO is rated at zero
clearance to combustibles.)
24"
3"
18"
0"
(From bac
k of
unit to wall)
(From bottom
of unit)
12"
(From front
of unit)
(From side
of unit)
3"
(From side
of unit)
(From top
of unit)
Page 6 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GENERAL INFORMATION/ELECTRICAL
WARNING
The EVO is certied as an indoor appliance. Do not install the EVO outdoors
or locate where it will be exposed to freezing temperatures. This includes
all related piping and components. If the EVO is subjected to ood water or
submersed in water, the EVO must be replaced.
NOTICE
Condensation Removal: This is a condensing, high efciency appliance, there-
fore condensation removal must be addressed to avoid damage to surrounding
area or appliance. See Part 4, Section F for Condensate Requirements (pg.20).
D. PRESSURE RELIEF VALVE
This unit is supplied with a relief valve sized in accordance with ANSI/ASME Heater and Pressure Vessel Code,
Section IV. The relief valve is installed near the hot water outlet. If the valve supplied is replaced, the pressure
rating of the valve must not exceed the listed working pressure of this appliance, and must be rated to the proper
BTU/hr capacity of the water heater. Do not, under any circumstances, thread a cap or plug into the relief
valve! Explosion, serious injury or death may result! To prevent water damage, the relief valve piping must
be directed to the oor or an open drain, but not connected directly. There must be a 6” space between the outlet
of relief valve piping and drain or oor. Do not hook up to drain system directly without an air gap. Protect from
freezing. Place no other valve between the relief valve and the unit. Do not install any reducing couplings or other
restrictions in the discharge line. The discharge line must allow complete drainage of the valve and line. Manually
operate the relief valve at least once a year.
Also, care must be exercised when choosing the location of this appliance, where leakage from the relief
valve, leakage from related piping, or leakage from the tank or connections, will not result in damage to the
surrounding areas, or to the lower oors of the building. A water heating appliance should always be located in an
area with a oor drain or installed in a drain pan suitable for water heating appliances. Under no circumstances,
shall Hamilton Engineering, Inc. be held liable for any such water damage whatsoever.
SERVICE
RESET
LO
TEMPERATURE
CH
OFF
ON
- +
INNOVATIVE CONDENSING T ECHNOLOGY
By Hamilton Engineering, Inc.
WARNING!
#1 Turn off power
to unit
#2 Remove bottom
screw(s)
WARNING!
Before removing screw and opening front cover,
main power supply must be disconnected (shut off).
HIGH VOLTAGE - RISK OF ELECTRICAL SHOCK!
14 15 16
L L
230 VAC
Power supply
ST-6
Fuse
To Ground
OFFOFF
OFF
Service Switch
ON
Junction Box
Junction Box
INNOVATIVE CONDENSING TECHNOLOGY
By Hamilton Engineering, Inc.
(FIGURE 1-4) HOW TO REMOVE THE FRONT COVER
Page 7 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
ELECTRICAL
PART 2. ELECTRICAL
A. ELECTRICAL CONNECTION
The electrical connection for the EVO is on the bottom of the unit. There is a 1/2” knockout location for an
electrical connection for the heater’s incoming power connection. All electrical wiring must be performed by a
qualied licensed electrician in accordance with National Electrical Code ANSI/NEPA to and/or the Canadian
Electrical Code, Part 1 CSA C22.1, or to the applicable codes and standards. For your convenience, we have
labeled all the points for electrical connections needed to operate the EVO.
The electrical requirements are for standard 208–240 volts, 50/60 Hz 15 Amp service. This unit is wired with #18
awg and internally fused for no more than 3.15 Amps. When the unit is rst powered on, there is a self-setting
of the electronics for 50 Hz or 60 Hz. At every power up, the electronics will take a couple of seconds to com-
pare the pulses of the power to the pulses of the crystal, which is built into the electronics. Then all time-related
functions are correct no matter the power source..
The standard supplied pumps are all 208–240 volt, 60 cycle and are wired to terminals on the heater. In 50 cycle
applications, other pumps may need to be supplied, depending on water conditions. With the 914 controller
there is an ability to program a custom pump delay time, or to use a continuous (no time out) setting. The factory
default is a 1 minute delay to turn off after completing a burn cycle.
B. INTERNAL WIRING CONNECTION
CAUTION
The incoming power shall be connected directly to the labeled, intended
connection points only. Failure to do so may result in an electrical short and
the control board will have to be replaced!
DANGER
IT IS EXTREMELY IMPORTANT THAT THIS UNIT BE PROPERLY GROUNDED!
IT IS VERY IMPORTANT THAT THE BUILDING GROUND IS INSPECTED BY A
QUALIFIED ELECTRICIAN PRIOR TO MAKING THIS CONNECTION!
Terminal 19 in the electrical compartment must be connected to the building ground system.
The incoming 208–240 volt single phase power supply is connected to terminals 18 through 20, which is factory
wired to the external box on the bottom of the appliance.
It is important that the electrical power is not turned on at this time. Double check all connections and then turn
the power on. The display that is provided with the EVO should now be reading the Setpoint temperature. Note:
See Start-Up Procedures (Part 6, Page 23) to change the temperature setting or run the appliance.
Page 8 of 50

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
Optional Connection Must connect + to + and - to - between appliances in cascade
Thermostat
Remote
-+
Cascade
Connection
Sensor
10k
Thermistor
External
Temperature
Optional Connection Used for storage tank or common line sensing Optional Connection Normally open dry contact or Open Term Thermostat Optional Connection Building management system Optional Connection For use with Central heating for outdoor reset
653 421
To Pump
Fused switch or from
a maximum 15 amp
dedicated circuit
breaker
208 - 240 VAC
L LL
60 Hz
208 - 240 VAC
L
Pump Power Supply
To Ground
15 16 17 201918
-+
0-10 VDC
Sensor
10k
Thermistor
Outside
Temperature
7 8 109
Lock Out
Signal
Dry Contact
Additional
Heat Source
Dry Contact
11 12 1413
Optional Connection
Optional Connection
For use with additional heat needed w/cascade For use with alarm bell / light
Service Switch
Junction Box
A B C D E F G H I
(FIGURE 2-1) FIELD WIRING CONNECTIONS
Page 9 of 50
A. External sensor connection - system temperature sensor, senses water temp in a storage tank or a
heating loop.
B. Cascade Connection - communication cables get connected here and “daisy chained” to all heaters/
boilers in a cascade. This is polarity sensitive.
C. Remote Thermostat - normally jumped. A room thermostat may be connected here to enable/
disable the heater/boiler.
D. 0-10 VDC - connect a 0-10 VDC output here to vary set point temperature.
E. Outdoor Sensor - outdoor air sensor, set point will adjust based on outdoor air temperature (not
needed if 0-10 VDC output is connected).
F. Lock Out Signal - alarm bell or light may be connected here.
G. Additional Heat Source - dry contacts that will close a thermostat on an extra heater/boiler if the
cascade system is at 100% of capacity.
H. Pump - the pump leads that are in the electrical box originate here.
I. Power Supply - main power connections in the electrical box originate here.

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GAS CONNECTION
PART 3. GAS CONNECTION
A. GAS CONNECTION
WARNING
Failure to follow all precautions could result in re, explosion or death!
(FIGURE 3-1) EVO GAS CONNECTION
The gas supply shall have a maximum inlet pressure of less
than 14” water column (1/2 PSI) (3.44 kPa), and a minimum
of 4” water column. The entire piping system, gas meter and
regulator must be sized properly to prevent pressure drop
greater than 1” as stated in the National Fuel Gas Code. This
information is listed on the rating plate. It is very important
that you are connected to the type of gas as noted on the
rating plate, “LP” for liqueed petroleum, propane gas or “Nat”
for natural or city gas. All gas connections must be approved
by the local gas supplier, or utility in addition to the governing
authority, prior to turning the gas supply on. It is mandatory
that a drip leg be fabricated, as per the National Fuel Gas
code. Once all the inspections have been performed, the pip-
ing must be leak tested. It is recommended that a soapy solu-
tion be used to detect leaks. Bubbles will appear on the pipe to
indicate a leak is present. If the leak test requirement is a high-
er test pressure than the maximum inlet pressure, you must
isolate the EVO from the gas line. In order to do this, you must shut the gas off using factory and eld-installed
gas cocks (following the lighting instructions in Part 6, Section B, Pages 23-24.) This will prevent high pressure
from reaching the valve. Failure to do so may damage the gas valve. In the event the gas valve is exposed to a
pressure greater than 14” water column, the gas valve must be replaced.

B. GAS PIPING
Page 10 of 50
The gas piping must be sized for the proper ow and length of pipe, to avoid pressure drop. Both the gas meter
and the gas regulator must be properly sized for the total gas load. If you experience a pressure drop greater
than 1” WC, the meter, regulator or gas line is undersized or in need of service. You can attach a manometer to
the incoming gas drip leg, by removing the cap and installing the manometer, see Figures 3-2 and 3-3 on the
following page. The gas pressure must remain between 4” and 14” during stand-by (static) mode and while in
operating (dynamic) mode. If an in-line regulator is used, it must be a minimum of 10 equivalent feet from
the EVO. It is very important that the gas line is properly purged by the gas supplier or utility. Failure to
properly purge the lines or improper line sizing, will result in ignition failure. This problem is especially
noticeable in NEW LP installations and also in empty tank situations. This can also occur when a utility company
shuts off service to an area to provide maintenance to their lines. This gas valve must not be replaced with a con-
ventional gas valve under any circumstances. As an additional safety feature, this gas valve is easily de-coupled
from the fan inlet.
Refer to the following tables to size the supply piping to minimize pressure drop between meter or
regulator and unit.

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GAS CONNECTION
Nominal Internal Length of Pipe (Feet)
Iron Pipe Diameter
Size
(in.) (inches) 10 20 30 40 50 60 70 80 90 100 125 150 200
BTUs
per
HR
x
1,000
3/4 0.824 567 393 315 267 237 217 196 185 173 162 146 132 112 }
1 1.049 1,071 732 590 504 448 409 378 346 322 307 275 352 213 }
1-1/4 1.380 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440 }
1-1/2 1.610 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675 }
2 2.067 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}
(TABLE 3-2) PROPANE SUPPLY PIPING (Based on 11” WC supply pressure)
C. GAS TABLES
D. GAS VALVE SETUP
Models 119–399 Model 599
2
1
3
2
1
3
4
(DO NOT TOUCH!)
DO NOT ADJUST
increase
increase
(FIGURE 3-2) EVO MODELS 79-399 (FIGURE 3-3) EVO MODEL 599
Page 11 of 50
(TABLE 3-1) NATURAL GAS SUPPLY PIPING
Nominal Internal Length of Pipe (Feet)
Iron Pipe Diameter
Size
(in.) (inches) 10 20 30 40 50 60 70 80 90 100 125 150 200
BTUs
per
HR
x
1,000
3/4 0.824 363 249 200 171 152 138 127 118 111 104 93 84 72 }
1 1.049 684 470 377 323 286 259 239 222 208 197 174 158 135 }
1-1/4 1.380 1,404 965 775 663 588 532 490 456 428 404 358 324 278 }
1-1/2 1.610 2,103 1,445 1,161 993 880 798 734 683 641 605 536 486 419 }
2 2.067 4,050 2,784 2,235 1,913 1,696 1,536 1,413 1,315 1,234 1,165 1,033 936 801 }
(Based on 0.60 specic gravity for natural gas at 0.5” WC pressure drop; DOE standard is 1100 BTU per
cubic foot of natural gas.)
1. Run the gas supply line in accordance with all applicable codes.
2. Locate and install manual shut off valves in accordance with state and local requirements.

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GAS CONNECTION
Measure the gas supply pressure at the pressure nipple [3] of the gas valve. The required gas supply pressure
needed for these appliances to work properly is greater than 4” and less than 14” WC. This pressure range
should be maintained during full gas load on the building where the appliance is installed.
(TABLE 3-3) COMBUSTION & FUEL RELATED ADJUSTMENT TABLE
Please note: All adjustments must be made with the appliance door off, which will lower the CO2 reading
0.2%. See tables above for specic readings.
Changing incoming air temperature may vary the CO2 setting slightly (~0.2 - 0.6%) after initial set up. This is not
cause for concern or reason to set up again. After one year of operation, set up is required again.
E. SETTING THE MAXIMUM LOAD
A means of sampling the leaving ue gas is built into each model, on all models there is a rubber plug mounted
in the vent connector on top of the appliance. Remove for testing and replace when testing is completed. This
plug MUST be in place during normal operation.
• Press the service button with a pointed object and set the temperature knob on the maximum fan speed as
shown by model in the table below (RPM = display * 100, ex. 060 = 6000).
(TABLE 3-4) FAN SPEED REQUIREMENTS
Page 12 of 50
Natural Gas CO2Natural Gas CO ppm LP Gas CO2LP Gas CO ppm
Cover On Cover Off Approximate, do not use for setup! Cover On Cover Off Approximate, do not use for setup!
LOW FIRE 8.5% 8.3% Less than 10 9.6% 9.4% Less than 15
HIGH FIRE 8.8% 8.6% Less than 110 10.0% 9.8% Less than 120
Last 4 digits of serial number HWD 79, HWH 79, HWH 79.8
First Week Last Week Maximum rpm Minimum rpm
33--07 01--08 5200 1664
02--08 current 6400 1856
Last 4 digits of serial number HWD 129, HWH 129, HWH 129.8
First Week Last Week Maximum rpm Minimum rpm
24--05 05--06 6500 1625
06--06 48--06 5200 1664
49--06 current 5900 1947
Last 7 digits of serial number HWD 179, HWH 179, HWH 179.8
First Week Last Week Maximum rpm^ Minimum rpm
001-13-06 008-13-06 6000 1920
009-17-06 086-29-06 5800 1856
009-43-07 023-48-07 5800 1856
009-43-07 008-48-07 5600 1680
024-11-08 182-29-08 5600 1736
^ Fan speeds 5800 & 6000 rpm require Hamilton P/N FAN 74313, 5600 rpm requires FAN 74351.

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
F. SETTING THE MINIMUM LOAD
Set the minimum load once the maximum load has been set, turn the knob until the minimum RPM setting
has been reached. In order to set or adjust the minimum load, turn the screw [2] for the minimum setting (rst
remove the protective cap). Turn the screw clockwise to increase or counter clockwise to decrease the CO2
percentage. On the HW 599, you only are allowed to set the gas valve at the right side; the left gas valve is set
by the manufacturer. See Section H for special instructions on replacing both gas valves in a model 599.
• If the measuring process takes more than 40 minutes, the appliance will return to the automatic mode.
If so required, press the Service button another time.
• When you are done setting the valve, press the Service button again to return to normal run mode
Please do not forget to replace the protective cap on the gas valve.
Page 13 of 50
If necessary, turn the adjusting slot [1], which sets the high re performance, either counterclockwise to increase
the CO2 percentage or clockwise to reduce the CO2 percentage, as shown in Figures 3-2 and 3-3, Page 11.
Appropriate CO2 percentages are shown in Table 3-3 on the previous page.
Do not forget to place the knob, labeled with “Setpoint,” at the proper temperature value when done.
Last 4 digits of serial number HWD 299
First Week Last Week Maximum rpm Minimum rpm
49--06 01--08 6300 1890
02--08 current 6300 1575
Last 4 digits of serial number HWD 399
First Week Last Week Maximum rpm Minimum rpm
24--05 current 6200 1798
Last 4 digits of serial number HWD 599
First Week Last Week Maximum rpm Minimum rpm
24--05 current 5700 1596
Last 4 digits of serial number HWD 199, HWD 199.1, HWH 199, HWH 199.1, HWH 199.8
First Week Last Week Maximum rpm Minimum rpm
24--05 48--06 5900 1711
49--06 current 6500 1755
GAS CONNECTION
If the appliance is to be converted in the eld for using Propane (LPG), the following steps must be taken:
• Turn screw [1] (Figure 3-2, page 11) .75 of a full turn (270°) on models HW 79/199.1,three quarters of
one turn (270°) on models HW 199/299 and 1 full turn (360°) on model HW399
• On model HW599 (Figure 3-3, page 11) turn screw on left hand valve closed (clockwise) and turn right
valve 1.75 of a full turn clockwise.
• Run the appliance. If the burner does not ignite after four starting efforts, turn the screw [1] one half turn
back (180°) (counter clockwise).
• After conversion, follow the steps in Sections E and F for setting the maximum and minimum loads,
using the LP gas values shown in Table 3-3, page 12.
G. GAS CONVERSION

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
GAS CONNECTION/VENTING
H. GAS VALVE MAINTENANCE/REPLACEMENT
WARNING
Failure to follow all precautions could result in re, explosion or death!
DANGER
It is extremely important to follow these venting instructions carefully. Failure
to do so can cause sever personal injury, death or substantial property damage.
1) When checking or replacing a gas valve, the CO2 percentage in the ue gas is the preferred
measuring method to insure proper combustion and ring rate. CO is used as the alternate.
2) Gas valve replacement for the HW 599:
The left hand gas valve (which is normally factory-set and sealed and must not be adjusted) must be set up to
factory specications before any combustion related adjustments can be performed on the right hand valve. An
electronic manometer must be used, as it will be set to a scale of 0.01” WC.
The adjustment screw [1] (see Figure 3-3, page 11) normally used for setting maximum ow rate must be turned
counterclockwise until it begins to click when turned. The screw will not fall out, but will be fully retracted at this
point. this is for Natural Gas, for LP gas, close the left hand valve (clockwise) until it is closed down.
The digital manometer must now be connected to the outlet pressure tapping [4] on the left hand valve only
(marked do not adjust in gure 3-3, page 11), and the appliance red. It must be placed in the service mode and
held at the minimum ring rate (1653 rpm fan speed). With the appliance ring at this rate, adjust the offset
(minimum ring rate) screw [1] to a pressure of “0” +/- .0.01” WC. Be sure the manometer has been zeroed
out prior to making this setting.
Once this operation is complete, you may follow the instructions for setting the minimum and maximum ring rate
as shown in Sections G and H, for the right hand gas valve only.
Page 14 of 50
Please note: Venting system may contain one or more of the above materials.
The EVO is a direct vent appliance. The EVO is listed as a Category IV. Condensing Appliance.

PART 4. VENTING
A. APPROVED VENTING MATERIALS

Item Material 
United States Canada
Vent pipe
and

PVC schedule 40 ANSI/ASTM D1785 CPVC and PVC venting must be ULC-
S636 Certied. IPEX is an approved vent
manufacturer in Canada supplying vent
material listed to ULC-S636.
PVC - DVW ANSI/ASTM D 2665
CPVC schedule 40 ANSI/ASTM F441
Pipe cement
& primer
PVC ANSI/ASTM D2564 IPEX System 636
Cements & Primers
CPVC ANSI/ASTM F493


34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
VENTING
Page 15 of 50
DANGER
It is extremely important to follow these venting instructions carefully. Failure
to do so can cause sever personal injury, death or substantial property damage.
WARNING
This vent system will operate with a positive pressure in the vent pipe. Do not
connect vent connectors serving appliances by natural draft into any portion of
mechanical draft systems operating under pressure.
Note: For concrete construction or to meet certain re codes, exhaust and inlet piping at the wall penetration to
the EVO must be CPVC Schedule 40 or 80 or stainless. The balance from the penetrated wall to the outside may
be PVC Schedule 40 or 80.
B. VENTING THE EVO
HW 79 3" Plastic Stainless 6' + (2) 90° elbows 225'
HW 129 3" Plastic Stainless 6' + (2) 90° elbows 200'
HW 199.1 3" Plastic Stainless 6' + (2) 90° elbows 100'
HW 179 3" Plastic Stainless 6' + (2) 90° elbows 200'
HW 299 4" Plastic Stainless 6' + (2) 90° elbows 3"=30' 4"=225'
HW 399 4" Plastic Stainless 6' + (2) 90° elbows 180'
HW 599 5" Stainless Plastic - 6” *6' + (2) 90° elbows 200'
Model Vent
Diameter
Standard
Vent Type
Optional Vent
Type
Minimum combined vent
length
Maximum
combined length
HW 199 3" Plastic Stainless 6' + (2) 90° elbows 95'
*The use of 6” PVC will require the purchase of a
special adapter from Hamilton Engineering, Inc.
(TABLE 4-1) VENTING SPECIFICATIONS
(TABLE 4-2) EQUIVALENT FEET
Fittings or Piping Equivalent Feet
90 degree elbow 5’
45 degree elbow 3’
Coupling 0
Air inlet elbow 6’
Exhaust coupling 1’
The inlet and exhaust pipes on the top of the cabinet should be the diameter and material indicated in the Venting
Specications Table above. It is very important that you plan the location properly to eliminate long pipe runs and
excessive ttings. Inlet pipe size must not be reduced. Do not combine the inlet air or exhaust with any other inlet
or exhaust pipe including either to an additional similar appliance, unless you have purchased an engineered
Common Venting System from Hamilton Engineering, Inc. The joints must be properly cleaned, primed and
cemented if plastic, and sealed per the manufacturer’s instructions if stainless. The piping must also be properly
supported as per Local and National Standard Plumbing Codes. It is important that the piping must be clean and
free from burrs, debris, ragged ends and particles of PVC (if applicable).

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
VENTING
Page 16 of 50
NOTICE
The following are code restrictions for the location of the ue gas vent terminal.
Compliance to these requirements doesn’t insure a satisfactory installation;
good common sense must also be applied. It is important to make sure that
exhaust gases are not recirculated into the inlet air of the EVO. If there is any
doubt, contact the factory BEFORE installing.
Exhaust piping should be sloped back to the connection on the EVO, at least 1/4” per foot to remove additional
condensate that forms within the pipe. The total combined length of pipe (intake piping plus exhaust piping added
together) including elbow allowances intake and exhaust should not exceed the length shown in the vent table.
The minimum combined vent length should not be less than a combined length of 6’ plus two 90° elbows. Choose
your vent termination locations carefully. You must also make certain that exhaust gas does not re-circulate back
into the intake pipe. You must place them in an open area and follow the following guidelines:
1) Never vent into a walkway, patio area, alley or otherwise public area less than 7’ from the ground.
(See detail below references Fig. A.12.9 in the National Fuel Gas Code 2009 “Exit Terminals of
Mechanical Draft and Direct-Venting Systems.” - see Figure 4-1, pg.17)
2) Never vent over or under a window or a doorway where the exhaust plume or condensation liquid will
cause obtrusive or dangerous conditions. (Refer to National Fuel Gas Code, CAN B149).
3) Never install a heat saver or similar product to capture waste heat from exhaust.
4) Always have a vent location at least 12” above maximum snow level.
5) Always have vent a minimum of 24” above ground level, away from shrubs and bushes.
6) Follow local gas codes in your region or refer to National Fuel Gas Code, Can B149.
7) Always have at least 36” distance from an inside corner of the outside walls.
8) Maintain at least 48” clearance to electric, gas meters, windows, exhaust fans, chimneys, inlets or
mechanical vents.
9) VERY IMPORTANT! The inlet air connection must be connected to outside air and should be located
no closer than 8” and no further than 24” to the exhaust.
10) Always place screens in all openings in intake and exhaust to prevent foreign matter from entering the
EVO.
11) The vent intake and exhaust must be properly cleaned and glued if plastic, and sealed per the
manufacturer’s directions if stainless for a pressure tight joint. Several methods for venting the EVO
can be found in Figures 4-2 and 4-3 of this section, on page 18. Use these layouts as guidelines: certain
site conditions such as multiple roof lines/pitches may require venting modications (consult Hamilton
Engineering, Inc.).

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
VENTING
Page 17 of 50
(FIGURE 4-1) EXIT TERMINALS OF MECHANICAL DRAFT AND DIRECT-VENT VENTING SYSTEM
* REFERENCE: THE NATIONAL FUEL GAS CODE 2009 EDITION
*IMPORTANT NOTE
HAMILTON ENGINEERING, INC.
RECOMMENDS A MINIMUM
CLEARANCE OF 4 FEET WHERE
THE EXHAUST PLUME CAUSED BY
THE UNIT MAY OBSTRUCT VIEWS
OR AFFECT THE COSMETIC LOOK
OF THE BUILDING. IN CANADA,
THERE IS A MINIMUM CLEARANCE
OF 10 FEET.
Through-the-Wall Vent Termination
12.9.1 A mechanical draft venting system shall terminate at least 3 ft (0.9 m) above any forced air inlet located
within 10 ft (3 m).
Exception No. 1: This provision shall not apply to the combustion air intake of a direct vent appliance.
Exception No. 2: This provision shall not apply to the separation of the integral outdoor air inlet and ue gas
discharge of listed outdoor appliances.
12.9.2 A mechanical draft venting system of other than direct vent type shall terminate at least 4 ft (1.2 m)
below, 4 ft (1.2 m) horizontally from, or 1 ft (300 mm) above any door, operable window, or gravity air inlet into
any building. The bottom of the vent terminal shall be located at least 12 in. (300 mm) above nished ground
level.
12.9.3 The vent terminal of a direct vent appliance with an input of 10,000 Btu/hr (3 kW) or less shall be located
at least 6 in. (150 mm) from any air opening into a building, an appliance with an input over 10,000 Btu/hr (3 kW)
but not over 50,000 Btu/hr (14.7 kW) shall be installed with a 9 in. (230 mm) vent termination clearance, and
an appliance with an input over 50,000 Btu/hr (14.7 kW) shall have at least a 12 in. (300 mm) vent termination
clearance. The bottom of the vent terminal and the air intake shall be located at least 12 in. (300 mm) above
nished ground level.

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
VENTING
Page 18 of 50
All horizontal runs must
be supported every 24"
Exterior wall
Intake
EVO
Exhaust
18" Minimum
24" Maximum
24" or 12"above
maximum snow level
whichever is greater
Right Side View
SHOWN OFFSET
FOR CLARITY
1/4" ft. slope to appliance
DIAGRAMS FOR SIDEWALL VENTING
Front Elevation
8
"
Front Elevation
(Multiple Vents)
8"
18" Minimum
24" Maximum
- OR -
VENTING FOR MULTIPLE
UNITS, with vents all on same
horizontal plane, spaced at least
8 inches apart, and at level of
highest unit.
PLEASE NOTE:
Exhaust must not terminate
beneath an overhang!
(FIGURE 4-2) SIDEWALL VENT WITH DOWN ELBOW (INTAKE) & UP ELBOW (EXHAUST)
**IMPORTANT NOTE: All vent pipes must be glued, properly supported and the exhaust must be pitched a
minimum of a 1/4” per foot back to the heater (to allow drainage of condensate). All stainless venting must be
sealed at each joint per manufacturer’s instructions.
DIAGRAMS FOR VERTICAL VENTING
Roof
24" or 12"above
maximum snow level,
whichever is greater
Front View
Exhaust
Intake
EVO
8"minimum
Minimum 12"above
anything within 10 feet.
18" minimum
24"
maximum
(FIGURE 4-3) VERTICAL VENT WITH DOUBLE
ELBOW (INTAKE) & COUPLING (EXHAUST)
**IMPORTANT NOTE: All vent pipes must be glued,
properly supported and the exhaust must be pitched a
minimum of a 1/4” per foot back to the heater (to allow drainage
of condensate). All stainless venting must be sealed at each
joint per manufacturer’s instructions.
Front Elevation
(Multiple Vents)
8"
18" Minimum
24" Maximum
min.
min.

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
VENTING
Page 19 of 50
CAUTION
Flue Gas will condense as it exits the vent termination. This condensate can
freeze on exterior building surfaces which may cause discoloration of these
surfaces. Consideration should be given to the plume of condensation that exits
the exhaust which may affect the cosmetic appearance of the building.
C. INLET AIR VENT
You may use the same material as used for exhaust or any material that is the same diameter that provides a
pressure tight connection. THIS IS ONLY FOR INLET AIR, NOT FOR EXHAUST PIPING!
The air inlet must be a minimum of 12” vertically above the maximum snow level. It is very important that there
are no other vents, chimneys or air inlets in any direction for at least 48”.
All venting must be properly supported. The EVO is not intended to support any venting whatsoever. All
piping, glue, solvents, cleaners, ttings and components, must conform to ASTM (American Society for Testing
and Materials), and ANSI (American National Standards Institute).
D. VENTING RUNS THAT EXCEED MAXIMUM COMBINED LENGTH
If the combined venting length of a heater’s exhaust/inlet air system exceeds the Maximum Combined
Length called out in Table 4-1, Page 15, contact Hamilton Engineering, Inc. for an engineered venting
calculation. Do not proceed without calling Hamilton Engineering, Inc. at 800.968.5530 or 734.419.0200.
VENT CALCULATION EXAMPLE: Installation requires the following material for both inlet and exhaust piping for
the EVO Micro HW 199.1 (maximum combined equivalent length is 100 feet).
Required: 6 Pcs. 90° elbow (6 x 5 = 30 equivalent feet) = 30 equivalent feet
Required: 20’ of Plastic PVC Pipe (20 x 1 = 20 equivalent feet) = 50 equivalent feet
Required: Inlet air in vertical termination (1 + 1 - 90° elbows) = 11 equivalent feet (includes inlet screen)
Required: Exhaust coupling = 1 equivalent foot
Total Friction Loss in equivalent feet = 92 equivalent feet
DANGER
The EVO is not intended to be common vented with any other existing
appliance! Multiple EVO products may be common vented only if using an
engineered system by Hamilton Engineering, Inc.
E. HEATER REMOVAL FROM AN EXISTING COMMON VENT SYSTEM
At the time of removal of an existing heater, the following steps shall be followed with each appliance that
remains connected to the common venting system placed in operation, while the other appliances that remain
connected to common venting system are not operating.
1. Seal any unused openings in the common venting system. The EVO venting is NOT to be combined
with this older 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.
THIS VENT SYSTEM IS OK!

34000 Autry Street, Livonia, MI 48150 • 800.968.5530 • Fax [phone] • www.hamiltonengineering.com • LIT91127 REV 3/09
Page 20 of 50
PIPING
3. If practical, close all building doors, windows and all doors between the space in which the
appliance remains connected to the common venting system 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 the appliance being inspected in operation. 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 common venting system
properly vents when tested as outlined, return doors, windows, exhaust fans, replace dampers and
any other gas burning appliance to their previous condition of use.
7. Any improper operation of the common venting system should be corrected so the installation con
forms with the National Fuel Gas Code, ANSI Z223.1. When resizing any portion of the common
venting system, the common venting system should be resized to approach the minimum size as
determined using the appropriate tables in Appendix G in the National Fuel Gas Code, ANSI Z 223.1
F. CONDENSATE REQUIREMENTS
This is a condensing high efciency appliance, therefore this
unit has a condensate removal system. Condensate is nothing
more than water vapor derived from the combustion products,
similar to an automobile when it is initially started. This conden-
sate does have a low pH and should be treated with a Conden-
sate Neutralizer Filter. This lter contains either lime or marble
rocks, which will neutralize the condensate. The outlet of the lter
is sized for 1.5” PVC pipe. It is very important that the conden-
sate line is sloped away from and down to a suitable inside
drain. A condensate neutralizer and a condensate pump kit are
available from Hamilton Engineering, Inc. It is also very impor-
tant that the condensate line is not exposed to freezing tempera-
tures, or any other type of blockage. Plastic tubing or PVC pipe
should be the only materials used for the condensate line. Steel,
brass, copper or others will be subject to corrosion and deteriora-
tion. A second vent may be necessary to prevent condensate line
vacuum lock if a long horizontal run is used. The EVO appliance
has an automatic safety device that will shut it down in the event
of a condensate drain blockage. Please test annually.
Maximum volume of condensate produced is 11 gallons per hour
per 1,000,000 BTU of gas burned.
Blocked Drain
Switch
Condensate Drain
From Heat Exchanger
Drain Tube
Drain Trap
Clean Out Cap
Hose From
Drain To Trap
Atmoshperic
Gravity Drain
Do not seal
the opening
between
these two
pipes , or
heater will
not fire.
PART 5. PIPING
A. HYDRONIC HEATING BOILER PIPING
(FIGURE 4-4)
CONDENSATE DRAIN DETAIL
The EVO is designed to function in a closed loop (minimum) 12 PSI System. Never let the EVO operate without
a minimum of 10 PSI water pressure, this assures that the EVO heat exchanger can be completely purged of
air, failure to do so could cause damage. It is important to note that the EVO Boiler is ow dependent for proper
efciency and life expectancy; therefore, primary-secondary piping or use of a low loss header design is always
recommended, as shown in the Figure 5-1. Each EVO Heating Boiler System should have an Air Eliminator, in
addition to the heat exchanger mounted air vent, which will remove air from the Hydronic System. Always follow
good piping practices. Observe minimum 1” clearance to combustibles around all uninsulated hot water pipes,

Heat exchanger
MUST be level or
pitched slightly to
the rear!