Omni OWB-25 Manual

Waste Oil Fired Boiler
Installation, operation and service instructions
OWB-25, OWB-35, OWB-50 120v Manual
EconoHeat • 5714 E. First Avenue • Spokane Valley, WA 99212 • 800.255.1363 • www.econoheat.com • Rev 09/2015

Page 2OMNI by EconoHeat
Table of Contents
Precautions ................................................................................... Page 3
Important Notice ......................................................................... Page 4
Oil Burner ....................................................................................... Page 5
Oil Burner Technology ............................................................... Page 7
Specifications ............................................................................... Page 9
Standard Equipment ................................................................ Page 11
Code Requirements ................................................................. Page 11
Combustion Air Supply ............................................................ Page 13
Chimney/Vent Requirements ................................................ Page 14
Installation ................................................................................... Page 15
Water/System Piping ................................................................ Page 19
Burner Mounting ........................................................................ Page 26
Boiler Jacket Assembly ............................................................ Page 27
Boiler Tube Insert Assembly .................................................... Page 29
Wiring ............................................................................................ Page 30
Start-up and Adjustments ....................................................... Page 34
Water Treatment ........................................................................ Page 35
Maintenance Schedule .......................................................... Page 36
Freeze Protection ........................................................................ Page 39
Troubleshooting ......................................................................... Page 39
OMNI Limited Warranty ............................................................ Page 40
Warranty Card ........................................................................... Page 41

Page 3OMNI by EconoHeat
PRECAUTIONS
Waste oil may contain many foreign materials. Waste oil may also contain
gasoline. Therefore, specific precautions on the handling and storage of waste
oils are to be observed when using, cleaning, and maintaining this heater. Use a
screen in a funnel when pouring oil into storage tank to catch foreign material,
i.e., gasket material and sealant fibers, etc. WARNING: This appliance is not
designated for use in hazardous atmospheres containing flammable vapors
or combustible dust, or atmospheres containing chlorinated or halogenated
hydrocarbons. Do not expose this unit to rain or moisture. If installed in high
moisture atmosphere, a special cover for the integrated air compressor
must be obtained from factory to avoid rusting of internal raw metals. If this
occurs, see trouble-shooting guide for remedy. OMNI burns the widest range of
used and new oils including, but not limited to: used motor oils up to 90 weight,
transmission and hydraulic fluid, used synthetic oils, crude oil, vegetable, fish, and
mineral oil,all diesel fuel and many more. Do not use old, contaminated oils that
have been stored in underground tanks or outside barrels for long periods of time.
Excessive water and sludge may be present, causing quick filter plugging.
NOTES: The instructions contained in this manual apply to the installation,
operation, and service of OMNI Waste oil fired boiler. The following instructions
should be carefully followed for obtaining the best possible installation, operation,
and service conditions. Specifications are subject to change without notice. This
product was designed to provide an economical disposal of wast oil. Proper
operation depends on the consistency of the oil. Any water or foreign material in
the oil may cause the unit to shut down. If a continuous stream of oil cannot be
guaranteed at the burner, the main system should be set above freezing which will
prevent any building damage if the waste oil heater were to become inoperative
during subfreezing weather, i.e. supply tank empty, filter plugged, etc.
UNCRATING: Immediately upon uncrating units, check rating plate for certainty
of electrical and mechanical characteristics. Also, check the unit for any damage
that may have been incurred in shipment, if any damage is found, file a claim
with the transporting agency. The unit has been tested and inspected at the
factory prior to crating and was in perfect condition at that time. If anything is
missing, check packing slip for indications of possible backorder of those parts or
components. Otherwise, a claim must be filed for those missing parts.

Page 4OMNI by EconoHeat
IMPORTANT
Notice to the owner and installer
To enjoy the long-term benefits of burning your used oil in an OMNI Waste Oil Burning appliance,
it is necessary to become familiar with the correct installation operation and maintenance
of your new furnace. Before installing or operating this appliance, make sure you read and
understand this manual.
IMPROPER INSTALLATION, ALTERATIONS, OR LACK OF MAINTENANCE WILL VOID THE
WARRANTY.
The most critical sections of this manual are in order of importance as follows:
• Basic Operation Knowledge
• Oil Suction Line Installation
• Correct Draft Over Fire
• General Maintenance Requirements
Identical to any gas or oil furnace, without adequate draft over the fire, the combustion
gases cannot escape the furnaces. The flame will lengthen resulting in an overheated
combustion chamber. Even if the boiler is installed correctly and adequate draft achieved,
a flue passage blockage will affect the draft. Burning used oil is similar to burning wood. A
fine gray ash accumulates in the chamber and flue passage. This accumulation of ash will
eventually affect the draft. It is important to remove this ash before the draft is affected.
These topics are discussed in detail on the pages listed above. Please familiarize yourself with
these sections of your manual. Spending a few minutes to review this material will assure that
you receive the return on investment that you expect from your OMNI boiler.
Note: All illustrations and specifications contained herein are based on latest information
available at the time of publication. EconoHeat reserves the right to make changes at any
time without notice.

Page 5OMNI by EconoHeat
Oil Burner
Installation and use of this used oil burning appliance shall be in accordance with
the standard for the Installation of Oil Burning Equipment – ANSI/NFPA 31 – 1987,
and National Electric Code – ANSI/NFPA 70 – 1990 and the requirements of the
inspection authorities having jurisdiction.
WARNING
Igniter
Transformer
Air Band
(combustion air
supply adjustment)
Power Indicator
Run Indicator
Figure 1 – Oil Burner (Back View Closed)
Oil Primary Control
Air Filter
Air Pressure Gauge
Air Pressure
Adjustment Screw
Motor Air Compressor
Figure 2 – Oil Burner (Back View Opened)
Electrical Terminal Block
Pre-Heater Control Circuit BoardTransformer
Pre-Heater Block

Page 6OMNI by EconoHeat
Oil Valve Burner Motor
Compressor Flame Cone
Nozzle
Electrodes
Figure 3 – Oil Burner (Front View)
Figure 4 – Oil Pump Diagram
Oil Inlet
Oil Outlet
Mounting Flange
(3 or 4 bolt universal pattern)
Vanes/Carbon Plate
(Remove Cover)
Filter
Oil Primer Switch
Inline Breaker

Page 7OMNI by EconoHeat
Oil Flow Control Supply Pump has the ability to control flame even when various viscosities are
used- furnace or stove oil to 90 weight straight- flame remains stable
Figure 5 – Oil Pump Assembly
Oil Shut-off Valve
(Eliminates start delays due
to possible drain back)
Spin-On Filter
Oil Primer Switch
(Solenoid valve, on/off)
Adjustable
Motor Speed
(Initial set up only; Once
set, no adjustment
needed thereafter)
Inline Breaker
Oil Burner Technology
OMNI’s patented burner technology improves the efficiency of the oil burn process by
continuous stabilization of the oil viscosity. Optimum atomization (spray) is accomplished
by precisely pre-heating the oil and air prior to introduction to the combustion chamber.
The waste oil enters into the Oil Pre-Heater Block (figure 4) and is pre-heated to operating
thermo set-point, then compressed air from the air compressor (figure 3) is mixed with the oil
prior to spraying out the nozzle similar to fuel injection, by breaking up the oil droplets into a
finer mist or spray (atomization). Electrodes mounted just above the nozzle (figure 5) provides
continuous electrical arc across electrode to electrode igniting the fine oil mist as it sprays out
of the nozzle. Once ignited the flame is forced into a swirl caused by the burners blower and
specially designed flame cone (figure 5) providing a very efficient and thorough burn of the
waste oil.
DC Motor
Oil Tank
Filter
Flow Control
Oil Pump
Internal Pump Filter
Air Compressor
On Burner
Oil Preheater
Inside Burner
Air Line to Preheater
Mixes with Oil at Nozzle
Suction Line
Pressure Line
Atomization Through Low Pressure
Preheat & Air Induction At Nozzle
Air Filter

Page 8OMNI by EconoHeat
Burner Components
• Igniter Transformer: (figure 3) Supplies high voltage to the electrodes generating electrical
arc igniting the oil.
• Oil Valve: (figure 5) energizes when burner is running and de-energizes when burner is not
running eliminating bleed back of oil out of the Pre-heater block.
• Air Band: (figure 3) Adjusts amount of air introduced into the combustion chamber. Air
band is adjusted at the factory for optimum performance, approx. ½ to ¾ inch open. NO
FIELD ADJUSTMENT REQUIRED unless in high altitudes application where minor adjustment
may be required.
• Oil Primary Control: (figure 3) Controls the oil burner ignition. Checks for flame in the
combustion chamber, if no flame is detected within 45 seconds, the oil primary will shutdown
the oil burner. To restart the unit, reset the red button on the oil primary.
• Oil Pre-Heater Block: (figure 4) Pre-heats the oil and air before entering combustion
chamber.
• Photo Eye: (figure 4) Senses flame in combustion chamber and signals oil primary when
no flame is present.
• Igniter Springs: (figure 4) Transfers the high voltage from the igniter transformer to the
electrodes (when door is closed)
• Air Pressure Gauge: (figure 3) Displays air pressure supplied by on-board air compressor.
• Air Compressor: (figure 3) Supplies air used within pre-heater block to aid in atomization
of the oil.
• Air Muffler/Filter: (figure 3) Filters air and muffles the sound generated by the compressor.
• Pre-Heater Control Circuit Board: (figure 4) Precisely controls temperature of the Oil Pre-
Heater Block and controls safety feature of not allowing burner to energize until oil has
established operating thermo set-point or shutdown burner if Pre-Heater Block temperature
falls below shutdown thermo set-point.
• Electrodes: (figure 4 and 5) Provides continuous high voltage electrical arc from electrode
to electrode igniting the waste oil as it is being sprayed out of the nozzle.
• Nozzle: (figure 5) Low-pressure nozzle for oil spray pattern.
• Flame Cone: (figure 5) Specially engineered flame cone forces the flame into a swirl pattern
improving the burn thoroughness.
• Burner Motor: (figure 5) Multi-task motor turns the burner blower and integrated air
compressor.
• Air Pressure Adjuster: (figure 3) Adjusts the air pressure going to the pre-heater block.
Should be adjusted between 12 PSI and 13PSI as indicated on the Air Pressure Gauge on the
burner for thorough burn of the waste oil. Note: In order to insure proper air adjustment,
air gauge must read 0 when burner is cycled off or powered down.
• Oil Pressure Adjustment: Adjust flame length in the heater combustion chamber viewed
through the inspection port located directly above the burner gun assembly by increasing
CW or decreasing CCW the adjuster located on the oil delivery pump (figure7). The adjuster
increases or decreases the pump motors RPM, which increases or decreases the delivery
of fuel to the burner. When you increase or decrease the fuel to the burner, you will notice
the flame length will increase or decrease. Adjust flame length so flame is just slightly less
than halfway down main combustion chamber tube.

Page 9OMNI by EconoHeat
IMPORTANT:
• Power Indicator: (figure 3) Indicates when power is present at the burner.
• Run Indicator: (figure 3) Indicates that the burner is ready for operation after the initial pre-
heat time of approx. 5 minutes from initial power up.
Oil Burner/Pump Specifications
Voltage 115 VAC
Cycles 60Hz
Total Operating Amperage (Burner Only) 8.4 Amps
Total Operating Amperage (Burner and Oil Pump) 10.5 Amps
Electrical Operating Consumption (Burner Only) 970 Watts
Electrical Operating Consumption (Burner and Oil Pump) 1,212 Watts
Weight 36.5 Lbs.
Oil Primary 0.2 Amps
Oil Valve 0.075 Amps
Pre-Heater Block 4.2 Amps
Pre-Heater Controller Board 0.011 Amps
Igniter Transformer 0.3 Amps
Burner Motor 3.6 Amps
Burner Assembly Performance Ratings
Voltage 115 VAC
Cycles 60Hz
Total Operating Amperage (Pump Assembly Only) 2.1 Amps
Electrical Operating Consumption (Pump Assembly Only) 241.5 Watts
Weight 16 Lbs.
Oil Valve 0.075 Amps
Pump Motor 2.0 Amps
Pump Assembly Performance Ratings

Page 10OMNI by EconoHeat
Boiler Specifications
Boiler
Manual
Burner
GPH
Input
BTU’s
Output
Capacity
BTU’s
Net
Rating
Water
BTU/hr
Rating
Water
Sq. Ft.
Approx.
Dry
Weight
(Lbs)
Vent
Connect
Diameter
(Inches)
Diameter
“L”
Inches
Water
Content
Gallons
Max
Water
Working
Pressure
OWB-25 1.7 250,000 212,000 184,700 1,450 902 74 4 -1/4 10.8 60PSI
OWB-35 2.4 350,000 2 97, 5 0 0 258,600 2,030 1654 10 52 28.5 75PSI
OWB-50 3.3 500,000 425,000 369,500 2,900 1831 10 57 31.7 75PSI
Notes:
1. Net ratings shown are based on piping and pick-up allowance of 1.15.
2. Net ratings in square feet are base on 170° Fahrenheit average water temperature in radiators.
For higher water temperatures, select boiler based on basis of net ratings in BTU per hour.
3. Firing rate in G.P.H. is based on oil having heat value of 150,000 BTU/gallon.
4. 4% reduction of output for every 1,000 feet of elevation.
Centerline of Burner Plate
36”
17”
33”
.75”
8”
9.375”
Approx. 14”
L
29.5”
4”
20”
2.5 M.P.T. Supply Connection
2.5 M.P.T. Return Connection
OWB-35 and OWB-50 Dimensions
26”
25”
12.25”
15.5”
21.5”
Approx. 14”
L
1.5 M.P.T. Return
Connection
1.5 M.P.T. Supply Connection
Circulator
OWB-25 Dimensions

P a g e 11OMNI by EconoHeat
Standard Equipment
Components Model 250 Model 350 Model 500
Factory Assembled Cast Iron Sections X X X
Flow Control Oil Supply Pump X X X
Waste Oil Burner X X X
Insulated Jacket X X X
Long Well (35-1020) X X X
Short Well (35-1010) X X X
High Operating Limit (L4008A) X X
Supply Manifold X X X
Refractory Insulated Hinged Front Door w/ Sight Glass X X X
ASME Relief Valve 30 PSI X X X
Spin-on Oil Filter X X X
Low Water Cut-off Control X X X
Manual Reset High Limit Aquastat Control (L4006E) X X X
10” Damper X X
Temperature/Pressure Gauge X X X
Important Code Requirements
Installations must comply with all state, local, and utility codes, laws, regulations, and
ordinances, and CSA standard B139. Where required by the authority having jurisdiction,
the installation must conform to American society of Mechanical Engineers Safety Code for
Controls and Safety Devices for Automatically Fired Boilers, No. CSD-1.
All electrical wiring must be done in accordance with the National Electrical codes latest
edition and all state and local codes.

Page 12OMNI by EconoHeat
OWB series boilers are three pass Scotch Marine design with fully water backed transfer
surfaces. Boilers are designed for use in forced hot water heating systems. Heating is supplied
by a Waste Oil Burner that burns all petroleum products any weight combination up to SAE
90W as well as fuel oils. Boiler–Burner units operate with no less than 0.01WC or greater over fire
and may be vented using a conventional chimney.
Relief Valve Manual Reset Limit
Modulating
Agustat Tapping
Supply
Manifold
Pressure/
Temp
Gauge
Transition Piece
to Flue Pipe w/
Quadrant Locking
Damper for Draft
Control
Rear Clean Out Ports
L 4008A Hi Limit Switch
Waste Oil
Burning Gun
Assembly
Complete
Third Pass
Second Pass
First Pass
Water flows
through all heat
transfer elements
OMNI Three Pass Design
Figure 6 – Boiler (OWB-25, OWB-35 & OWB-50)

Page 13OMNI by EconoHeat
Combustion Air Supply
Failure to provide an adequate supply of fresh air for combustion will result in
hazardous operating conditions. If you use a fireplace or a kitchen or bathroom
exhaust fan, you should install an outside air intake. These devices will rob the
boiler and water heater of combustion air.
WARNING
1. In unconfined spaces in buildings infiltration may be adequate to provide air for combustion
and ventilation. However, in buildings of unusually tight construction, additional air must
be provided as described in Item2. (b) below.
2. Boiler located in confined space: [Note: Confined space may be defined as a space whose
volume is less than 50 cubic feet per 1000 Btuh of total input of all appliances installed in
that space.]
a) All air from inside of building: Providing infiltration in the rest of the building is adequate,
the confined space may be provided with two permanent openings communicating
directly with another room or rooms of sufficient volume that the total volume of all spaces
meets the criteria for unconfined space. One opening must be within 12 inches of the
bottom of the enclosure. See Figure 7.
b) All Air From Outdoors:
The confined space shall be provided with two permanent openings, one within 12 inches
of the top and another within 12 inches of the bottom of the enclosure. The openings
shall communicate directly, or by ducts, with the outdoors or crawl or attic spaces which
communicate freely with the outdoors.
Note: Each
opening shall
have a free area
of not less than
one square inch
per 1,000 Btu per
hour of the total
input rating of all
equipment in the
enclosure, but
not less than 100
square inches.
Chimney
Opening
Opening
Note: The inlet
and outlet air
openings shall
each have a free
area of not less
than one square
inch per 4,000
Btu per hour of
total input rating
of all equipment
in the enclosure.
Chimney
Outlet Air
Inlet Air
Ventilation Louvers
(each end of the attic)
Alternative
Air Inlet
Ventilation Louvers
(for unheated crawl space)
Figure 7 – Air from inside
Figure 8 – Air from outdoors

Page 14OMNI by EconoHeat
NOTE: All wall openings directly to outdoors must be screened to prevent entry by birds or
small animals.
Chimney or Vent Requirements
Inspect existing chimney to make sure it is clean, the right size, properly constructed
and in good condition before installing boiler. Failure to do so may cause a
hazardous operating condition.
WARNING
NOTE: Venting must conform with applicable local codes and National Board of Fire Underwriters.
1. Chimney must be a Class A chimney.
Chimney
Outlet Air Duct
Inlet Air Duct
Note: Each air duct opening shall
have a free area of not less than
one square inch per 2,000 BTU per
hour of the total input rating of all
equipment in the enclosure.*
*If the equipment room is located against an outside
wall and the air openings communicate directly with
the outdoors, each opening shall have a free area of
not less than one square inch per 4,000 BTU per hour of
the total input rating of all equipment in the enclosure.
Figure 10 – With horizontal ducts
Boiler Model Minimum Breaching
Diameter (inches)
Minimum Recommend
Chimney Diameter (inches)
Minimum Recommend
Chimney Height (feet)
OWB-25 7" 8" 20'
OWB-35 10" 10" 15'
OWB-50 10" 10" 15'
Table 1: Minimum Recommended Breaching and Chimney Size
Note: The inlet
and outlet air
openings shall
each have a free
area of not less
than one square
inch per 4,000
Btu per hour of
total input rating
of all equipment
in the enclosure.
Chimney
Outlet Air
Inlet Air
Ventilation Louvers
(each end of the attic)
Alternative
Air Inlet
Figure 9 – With vertical ducts

Page 15OMNI by EconoHeat
2. This is a high efficiency boiler which operates with a low stack temperature which may be subject
to condensation in a cool or improperly designed chimney. Accordingly, the right vent or liner is
very important.
• Masonry chimney with three walls exposed to outdoors may require the use of a 316 stainless
steel liner.
• Masonry chimney with all inside walls—use a tile liner.
3. Breaching
• See Table 1 for minimum recommended breaching and chimney sizes.
• Keep run boiler to chimney as short as possible.
• Use as few elbows as possible.
• Slope upward towards chimney at not less than 1/4” per foot.
• Use a sealed-in thimble for the chimney connection.
• Connect together all sections and fittings with sheet metal screws and seal with silicone sealant.
4. When more than one appliance is connected to the same chimney, the chimney’s internal cross-
sectional area must be at a minimum equal to the area of the largest vent plus 50% of the area of
each additional vent.
5. Clearances—vent pipe between boiler and chimney must be a minimum of 6” from any
combustible material.
6. An oil-fired unit shall be connected to a flue having sufficient draft at all times, to assure safe
proper operation of the unit.
SIDE-WALL VENTING---IMPORTANT NOTE
Two problems arise when side wall venting any oil appliance;
1. There can be an accelerated rate at which soot builds up on the cad-cell, spinner, etc.
2. There is the potential for severe soot damage to the side of the structure in the event that
the boiler operates at a high smoke level. This can happen for many reasons, some of
which are out of the control of both the installer and appliance manufacturer.
EconoHeat recommends the use of a chimney to vent our residential oil boilers. If a power
venter must be used, it is the responsibility of the installer and power vent manufacturer to
“engineer” the power vent system.
ECONOHEAT WILL ASSUME NO RESPONSIBILITY FOR SOOT DAMAGE TO SIDING FROM A
POWER VENTED OIL BOILER. THIS APPLIES REGARDLESS OF THE CAUSE OF THE SOOTING.
Locating the Boiler
Boiler must not be installed in an area where gasoline, paint or other combustible
materials or flammable vapors or liquids are present.
WARNING
Consider all piping and venting connections before selecting a location. Locate as close to
the chimney as possible, observing the following clearances requirements from combustible
surfaces:

Page 16OMNI by EconoHeat
Front – Additional clearance is required for insertion and removal of the Tube Insert as noted for
each model:
• OWB-25 38.5”
• OWB-35 38.5”
• OWB-50 43.5”
Top – 6” above controls
Left Side – 6”
Right Side – 6”
Back – 18”
Boiler is not intended for installation on combustible floor. Further, to facilitate servicing it is
desirable to raise the boiler at least 8” off the floor. It is recommended that concrete blocks be
employed to build up a foundation. Ensure that top surface of foundation is level.
Installing the Boiler
1. Move the boiler as close as possible to its final location in the crate.
2. Remove the two lag screws holding the rear feet to the skid.
3. Remove the front jacket panel. Cut the band holding the front of the boiler to the skid.
4. Move the boiler into the final position.
5. Waste Oil Piping: USE ONLY 3/8” nominal ID copper piping with flare fittings only on the oil
suction from the tank to the oil pump and oil pump to burner. DO NOT use ferrule fittings
or teflon tape on any pipe fittings. Keep suction line approximately 6” from bottom of
oil tank to prevent suction of sludge (Figure 11). Use only an inside oil storage tank. Do
not draw from an outside tank, especially not an underground tank directly to burner. A
separate transfer pump from an outside tank with proper filtration to the inside supply tank
is acceptable.
6. The fuel pump included with burner is to be mounted at tank level or below. PUMP MUST
BE MOUNTED HORIZONTAL AND LOCATED NEXT TO WASTE OIL SUPPLY TANK.
Waste Oil Supply Tank Waste Oil Pump
Oil Feed Line, 3/8” to connector on burner gun assembly
O Suction Line, 3/8” copper piping
Suction Line 6” min from bottom of tank to prevent sludge from being introduced into the supply line
3
21
Boiler
Figure 11

P a g e 17OMNI by EconoHeat
Breaching Installation
The over fire draft should be minimum of -0.02 or more. Refer to Table 1 for minimum breaching
sizes. Breaching run should be as short as possible with as few elbows a practical. Unless
marginal draft conditions exist, a barometric draft control must be installed in the breaching
and should be approximately 18 inches from the boiler breaching connection. Breaching
should not project into the chimney beyond the inside wall of the chimney. Connect the
breaching to the chimney with a thimble or slip joint to facilitate cleaning. See Figure 12.
Pitch Up 1/4” per foot
Barometric Draft Control
Straight Run Preferred
18"
Installing the Boiler Controls & Accessories
1. Accessories for Boilers OWB-25:
a) Take the L-7248C Aquastat relay, the well, the pressure relief valve with pipe nipple and
the temperature/pressure gauge from the large carton. Install in taps provided at the
top rear of the boiler as shown in Figure 13.
Figure 12
Figure 13

Page 18OMNI by EconoHeat
b) Take the boiler drain from the same carton and connect it to the 3/4 inch opening of
the 1 1/4 x 3/4 x 1 1/4 inch tee in the boiler return manifold at the bottom rear of boiler.
c) Install 1 1/4 x 3” Nipple and Circulator Flange.
d) Remove the circulating pump from its carton in the crate and mount it to the pump
flange on the end of the return manifold.
2. Bare Boiler:
a) The pressure relief valve and temperature/pressure gauge are supplied with the boiler
and should be mounted as shown in Figure 13.
b) The bare boiler does not include the return manifold. The installer must make up his
own manifold to connect to the 2 x 1 1/4 inch bushing which is supplied in the boiler
supply and return ports, and must provide his own boiler drain and circulating pump.
3. Accessories for Boilers OWB-35 and OWB-50:
a) Attach supply manifold as shown in Figure 14.
b) Install return port diffuser and attach return flange as shown in Figure 15. Make sure
diffuser SLOTS face upward.
c) Screw threading used on these parts are metric. There is no English thread equivalent
to the nuts or studs supplied. Attempts to use any English threaded stud in place of
those supplied will damage the boiler block.
Figure 14 – Supply Manifold Assembly
Figure 15 – Return Diffuser Installation

Page 19OMNI by EconoHeat
Water Piping Connections
1. To make the piping connections to the boiler ready to connect to the system piping, the
following will also be required at a minimum:
• 1 – Air Purger (same size as supply pipe)
• 1 – Pressure reducing Fill Valve
• 1 – Expansion Tank (sized to system design requirements)
• 1 – Automatic Air Vent
2. The following accessories may also be required, depending upon overall system design
and code requirements:
• 1 – Low Water Cutoff may be required (Electronic Probe Type 550 LWCL included) if boiler
is located above radiation level. Check requirements of state or local code bodies and
insurance companies. If required use a probe-type designed for water system use and
install in tee in supply piping above the boiler.
• 1 – Manual Reset High Limit----Required by some state or local codes. Also required if
system is to comply with ASME code.
• 1 – Backflow Preventer----- Required by many State and local codes.
3. Additional circulating pumps or zone valves may also be required if the system is to be
multi-zone or if it is to include a domestic hot water storage tank with coil.
4. There are two types of expansion tanks used, the closed type and the pre-pressurized
diaphragm tank Most new installations use the diaphragm type tank, however some
installations still employ the closed type tank.
• Piping Connections with closed type expansion tank----See Figure 16. Piping from tee in
supply to tank should be 3/4 inch.If horizontal piping is employed,pipe must be pitched
up toward tank 1/4 inch per foot.
• Piping connections with diaphragm expansion tank--- See Figure 17. The cold water
feed to the pressure reducing fill valve may be piped with 1/2 inch pipe.
The expansion tank must be properly sized to system requirements. An under-sized
expansion tank will cause system water to be lost through the relief valve and
make-up water to be introduced through the fill valve. Continual introduction of
fresh water into the system will cause mineral build-up in the boiler sections and
eventual section failure.
WARNING

Page 20OMNI by EconoHeat
Figure 16
Closed Type Expansion Tank
Circulation Pump
Return from System
Fill ValveCold Water Feed
Pressure Relief Valve
3/4 in.
Shutoff Valve
Supply to
System
Drain Cock
Figure 17
Discharge Type
Expansion Tank
Circulation Pump
Purger
Cold Water Feed
Shutoff Valve
Auto Air Vent
Drain Cock
S
R
S
R