Electro Industries EB-MX-10 Manual

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ELECTRO-BOILER
Midsize
INSTALLATION & OPERATING INSTRUCTIONS
Model EB-M(S or X)-10
EB-M(S or X)-15
EB-M(S or X)-20
APPLICATION: This Electro-Boiler is factory equipped with WarmFlo smart controller.
WarmFlo automatically regulates outlet water temperature based on a desired
output temperature set point.
Primary application is any hydronic water heating system where reduced flow or
radiation can cause overheat conditions (example, zones). However, if it is a
mixture of large and small zones, the sudden capacity and flow changes may
cause some internal timing/over temp conditions. With the mixture of zones the
Electro Industries’ zone controller option is highly recommended.
This series is equipped for load management interrupt and can apply to standard
baseboard radiation (not recommended for EB-MS Model), dual heat
combinations, under floor radiant, wood boiler supplement, etc.
Note: If this installation does not include dual heat standby boiler, the front panel
switch must always be in the “normal” position.
ACCESSORIES: Attached BL001 lists various accessory or option items which are not part of
basic Electro-Boiler. See Room Thermostat Placement section for additional
information on slab stat.
Note: This product meets the requirements of the ASME Boiler and Pressure Vessel Code.

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TABLE OF CONTENTS
Description Page
Introduction 1
System or Water Flow 2
Multiple Zones & Radiant Temperatures 2
Zone Controller 2
Room Thermostat Placement 3
Two-Temperature Operation or Feature 3
Multiple Boilers 4
Boiler/Plumbing Kit Placement 5
Installation Requirements 5
Mechanical Installation
Under-Floor Radiant 7
Dual Heat 8
Electrical Hookup 9
Standby Boiler 10
Water Fill Procedure 10
Controller Setup 11
Staging/Modulating Jumper 12
Operational Tips 13
Standby Switchover, SOT Timer 14
Replacement Parts List 15
Troubleshooting/Repair Helps 16
WarmFlo Operational Information 17
Drawings:
Hookup BH511
Basic Mechanical BX505
Plumbing, Series Dual Boilers BX506
Internal Wiring Schematic UAW416
Low Voltage Wiring Diagram UAW849
Boiler Accessories BL001
Warranty XX017

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INTRODUCTION
With this WarmFlo configuration, the electric heating elements are automatically staged/modulated and
controlled to establish a fixed outlet water temperature. This outlet temperature is sensed by the
WarmFlo controller and is controlled to achieve and maintain the boiler’s set point temperature.
Even though this WarmFlo configured unit adjusts outlet temperature independent of water flow and
prevents high limiting even with marginal water flow, it is still very important that the hydronic system be
correctly designed for the building, the total heat loss requirement, and proper hydronics design and
installation practices. This boiler is the energy source for the water flow and radiation system. If the
water flow and radiation systems are not adequate for the Btu/h heat loss of the building, installing the
Electro-Boiler with WarmFlo will not necessarily supply the comfort and heating for the building.
“Cold boiler” notation – do not, under any circumstances, simply jumper R and W and allow the
temperature sensing controller to operate this Electro-Boiler as a “hot boiler”. Unless there is at least 2
GPM flow, the staging delays will cause temperature overshoot and could open up the manual reset
limits.
In most dual heat installations this Electro-Boiler is plumbed in parallel with an existing oil, gas, or wood
boiler. The Electro-Boiler is generally at the gas/oil outlet; but for wood, the Electro-Boiler must be on
the inlet sides. The standby boiler cannot be operated as “hot boiler”. This will defeat the Electro-Boiler.
Rewire as required, standby boiler is turned on from the brown wires (included with this boiler).
In the case of existing fossil fuel boiler conversions, it is assumed the expansion tank, valving, air
bleeder, and circulation pump are in place, in good operating condition, and adequate for the overall
system design.
In the case of new installation (floor radiant or baseboard), use standard hydronics water heating practices
for the necessary expansion tank, air bleeder, valving, water pump, etc., sized for the total capacity of the
system. The Electro-Boiler is turned on with an “R and W” closure from the zone system wiring.
208 Volt application – the elements within the standard product are rated a 240 volts. If operating at
208, there will be approximately 25% reduced capacity. The internal transformer may or may not
adequately operate the control system from a 208 source. Voltage measurements between “R” and “C”
must be 22VAC or greater when the system is in the complete operational mode. True 3-phase, 208-volt,
models are available in the WarmFlo Series, models EB-WX-13-2 and EB-WX-27-2, contact factory.
In the case of under floor radiant heating, the basic components for the electric energy, heating system
typically includes:
1. Electric boiler itself – covered by this manual.
2. Plumbing kit or piping material at the boiler itself – can be ordered as a kit.
EB-PK-M – shown on plumbing installation drawing BX505.
3. Circulating pump – typically sized for head pressure and system flow requirement, typical
catalog number 5586/5582.
4. The under floor circulating tubes and manifolds – provided and manufactured by others, not
covered in this manual.
APPROVED TUBING/PIPING
When plumbing this boiler and its peripheral parts to the loop system, all plumbing parts and/or tubing
must be sealed to prevent entrance of oxygen.
Use only tubing or polyethylene tubing with oxygen Diffusion Barrier.

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SYSTEM OR WATER FLOW
In order to prevent hi-limiting and assure full 20+ years parts life, the piping system/basic
plumbing/circulator pump must be arranged to provide flow greater than minimum GPM shown in Table
1. If zoned system, this applies when the smallest zone is operating.
NOTE: Since this is an automatic temperature sensing system, both sensors and the complete control
wiring are required before using or turning on this Electro-Boiler.
TABLE 1 - ELECTRO-BOILER SPECIFICATION
240 volts, 60 Hz, single phase
Model Btu/h Rating Amp Breakers Stages GPM
EB-S/MX-10 34,000 10 kW 42A 60 2 2-4
EB-S/MX-15 51,000 15 kW 63A 60, 30 3 2-6
EB-S/MX-20 68,000 20 kW 83A 60, 60 4 2-8
MULTIPLE ZONES AND RADIANT TEMPERATURES
Same water temperature all zones – in this case the system can be setup as one pump with the water
circulated through the boiler and directly to a manifold containing the various zone valves. Although this
model series has a built-in outlet sensing and controller mechanism for staging the elements, also consider
the next section, Zone Controller. If not using zone controller, the end switches of all of the zone valves
are paralleled and directly control R and W to turn on the boiler.
Various water temperature requirements – if this is the case, a primary loop with mixing valve for the
various zone temperature requirements is necessary. Injection pump techniques can also be used.
However, usually injection pump techniques come with a controller which is designed to protect a gas
boiler from cool water return. This is simply not needed and a duplication with the temperature sensing
controller within this Electro-boiler and the injection pump controller will be of no benefit within the
operating system. The zone valve/zone pump control strategy must be wired to provide the boiler “R and
W” contact closure and the primary pump is connected to the boiler pump contacts. This assures the
primary pump is active and running whenever the boiler is turned on via contact closure on “R and W”.
At least one zone must be open before turning on the primary pump/Electro-Boiler. Do not design a
system where the Electro-Boiler is supposed to operate as a “hot boiler” based upon its outlet sensor
without the primary pump circulating water, minimum 2 GPM is required.
Electro Industries’ Zone Controllers – the Electro Industries’ zone controller priority zone has the
ability to communicate with this TS Series boiler and it will automatically switch to a low mass high
water temperature (150 or 180) during zone 1, priority switch on, operation. With this feature the TS
boiler can automatically take care of two temperature requirements thus eliminating the need for the
technique described in the paragraph above.
ZONE CONTROLLER
This Midsize Series boiler controls the electric elements based upon water temperature independent of
flow; therefore, in theory, a staging zone controller is not required; however, there are three suggestions
or reasons why a zone controller can simplify the installation and enhance overall performance.
1. Zone wiring and troubleshooting convenience – the addition of the zone board allows for easy
terminal block and point to point wiring for each zone thermostat and each zone valve. Also there
are LED’s associated with the thermostat action and the zone valve action. This greatly simplifies
wiring and future troubleshooting with a neat terminal block wiring arrangement and the onboard
LED’s.
2. Prevents over control or false staging up and down when the temperature sensors are
attempting to regulate – since Electro Industries’ zone controllers have staging “smarts”, the
addition of the zone controller will provide smoother boiler temperature control. The zone board has

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a dial switch for each zone and the installer selects one of four zone capacity sizes. When dialing in
the size closest to the zone Btu/h capacity, the zone controller “smarts” only allows the appropriate
boiler stage which can handle that capacity. Also this is additive if more than one zone calls at any
one time.
3. Two temperature system with unbalanced zones – if the application includes zone one requiring
high temperature (fin tube, air handler, etc.) and the remaining zones are radiant floor low
temperature, this zone controller will automatically raise the output of the high temperature zone.
This is a priority arrangement, zone 1 holds off the other zones while the high temperature output is
heating. If at the end of the high temperature zone there is a call on any of the low temperature
zones (up to three plus slave 4), there will be a pump only function until the outlet temperature drops
below the front panel dial setting.
ZONE CIRCULATORS
The EE-5051 switching relay can be used to interface line voltage pumps with the boiler R and W control
terminals, see drawing BH008. However, when using zone controller EB-ZEA-1, these are not required.
ROOM THERMOSTAT PLACEMENT
Fin tube radiation, fan coil, etc. – heat only wall t-stat, connected to operate zone valves (see previous
section) or for single zone the t-stat is connected directly to Electro-Boiler R and W.
Floor radiant – comfort and proper space heating response is a direct relationship to the thermostat type
and the placement of the thermostat sensing bulb. Typically an under floor heating system can be broken
down into three categories.
A. Energy storage, water tubing is under the concrete or within the
sand base – the controlling thermostat must have a remote bulb, and
this remote bulb must sense the concrete slab temperature (slab stat).
Coordinated with the concrete pour, install a ¾” PVC, minimum bend
radius of 7 inches, and locate at approximately center (vertical) of the
concrete slab. The thermostat sensing bulb can later be pushed down
this PVC conduit. If the slab is already poured without conduit for slab
stat, use electronic remote sensing thermostat.
B. Floor covering, medium to high insulation – use slab stat as described in paragraph A above.
C. Quick response, hydronic tubing just under the concrete surface, no flooring material over the
concrete – in this case, heated water can directly radiate into the room, a standard wall mount room
thermostat is adequate. Mount room thermostat on an inside wall similar to most heating systems.
TWO-TEMPERATURE OPERATION OR FEATURE
When using Electro’s zone controller in priority mode, the boiler system can
automatically raise the outlet temperature with zone 1 calling. This is setup
for default of 150° or pulling a jumper peg the high temperature value is
176°. See appropriate zone controller installation manual for details.

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MULTIPLE BOILERS
This boiler series now includes a method for automatically staging any
number of parallel-plumbed boilers. Order plug-in relay EB-C-STG5.
The thermostat is connected only to the first boiler, when all stages are
on for more than 5 minutes, this new plug-in relay module turns on the
next boiler (R and W), and a second EB-C-STG5 could be used to turn
on the third, etc.
Outdoor Reset Option
The EB-MX-** boiler comes equipped with an outdoor sensor (shipped loose). This sensor can be
connected to the board to allow for outdoor reset function.
What is Outdoor Reset?
Outdoor reset is where the Electro Boiler DT (desired water temperature) shifts up and down based on the
outdoor temperature. The water temperature coming out of the boiler will be higher when it’s cold outside
and lower when it’s warmer outside. The idea is to have the boiler work with the building heat loss to
maintain a more even BTU delivery to the space. This helps with overall system efficiency as well.
NOTE: The EB-MS-** does not include an outdoor sensor. However, one can be ordered if outdoor
reset is required.
Outdoor sensor part number: WFS25F
Outdoor Reset Activation
If it is determined that outdoor reset is required for this application, it needs to be activated.
Follow this sequence to activate outdoor reset:
Step 1: Power down the Electro-Boiler
Step 2: Connect the outdoor sensor
Red wire to “RED”
Black wire to “OT”
White wire to “COM”
Step 3: Power up the Electro-Boiler
See: CONTROLLER SETUP for more information on outdoor reset.

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BOILER/PLUMBING KIT PLACEMENT
This model series is wall hung and the vessel must be vertical, drawing BX505.
The plumbing kit items are located adjacent to the boiler housing itself as shown on drawing BX501 or
BX505.
For future servicing, the unit itself must be installed 20” or more above the floor, the elements are
screwed in from the bottom.
INFORMATION/WATER FLOW CALCULATIONS
Water flow, GPM, can easily be calculated if the temperature rise across the electric boiler can be
measured.
The formula below can only be used when the temperature rise is stable and the boiler is not hi-limiting.
In other words, verify constant current draw and stable outlet temperatures for at least 15 minutes.
GPM = Volts x Amps x 3.4
500 x Temp. rise
INSTALLATION REQUIREMENTS
1. All installation work must be performed by trained, qualified contractors or technicians. Electro
Industries, Inc., sponsors installation and service schools to assist the installer. Visit our Website at
electromn.com for upcoming service schools.
WARNING
ALL ELECTRICAL WIRING MUST BE IN ACCORDANCE WITH NATIONAL ELECTRIC CODE
AND LOCAL ELECTRIC CODES, ORDINANCES, AND REGULATIONS.
WARNING
OBSERVE ELECTRIC POLARITY AND WIRING COLORS. FAILURE TO OBSERVE COULD
CAUSE ELECTRIC SHOCK AND/OR DAMAGE TO THE EQUIPMENT.
CAUTION
This unit can only be used for its intended design as described in this manual. Any internal
wiring changes, modifications to the circuit board, modifications or bypass of any controls, or
installation practices not according to the details of this manual will void the product warranty,
the CSA/us certification label, and manufacturer product liability. Electro Industries, Inc.,
cannot be held responsible for field modifications, incorrect installations, and conditions which
may bypass or compromise the built-in safety features and controls.
2. This installation manual and Electro-Boiler products relate only to the addition of the Electro-Boiler
to the hydronics system. The owner/ installer assumes all responsibility and/or liability associated
with any needed installation of the gas/oil boiler, pump, plumbing, system design, hydronics systems
or backup gas/oil boiler, etc. Any instructions or comments made within this manual (or factory
phone assistance) relating to the gas/oil furnace are provided as comments of assistance and “helps”
only.
CAUTION
Hazards or unsafe practices could result in property damage, product damage, severe personal
injury and/or death.

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3. Remember, safety is the installer’s responsibility and the installer must know this product well
enough to instruct the end user on its safe use.
Safety is a matter of common sense - - a matter of thinking before acting. Professional installers have
training and experienced practices for handling electrical, sheet metal, and material handling
processes. Use them.
CLEARANCES
MINIMUM CLEARANCE FROM
COMBUSTIBLE SURFACES SUGGESTED MINIMUM SERVICE CLEARANCE
BACK 0 INCH 0 MM 0 INCH 0 MM
LEFT 1 INCH 25 MM 12 INCHES 305 MM
RIGHT 1 INCH 25 MM 6 INCHES 152 MM
FRONT 1 INCH 25 MM 24 INCHES 610 MM
TOP 1 INCH 25 MM 24 INCHES 610 MM
BOTTOM REQUIRED CLEARANCE – 18 INCHES/457 MM

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MECHANICAL INSTALLATION – UNDER-FLOOR RADIATION
CAUTION
Electro Industries Inc. requires the use of dielectric isolation between the boiler vessel supply
and return piping when the boiler is plumbed using copper or any other dissimilar metal.
Damage to the vessel caused by galvanic corrosion voids Electro Industries’ warranty.
Reference drawing BX505
1. With the typical radiant floor system, a dual heat backup boiler is uncommon. If a backup boiler is
required, please reference “Mechanical Installation – Dual Heat” section.
2. Unpack the Electro-Boiler, the safety relief and pipe fittings are packed within a small carton. The
safety relief is plumbed to the ¾” bushing as shown on BX505.
3. The Electro-Boiler must be positioned with the vessel vertical. The water IN/OUT ports must be at
the top. The unit will not function properly with the vessel in a horizontal position.
NOTE: Mount at least 20 inches above the floor to allow element removal and service at the
bottom.
4. The plumbing components and plumbing layout shown on drawing BX505 have been very carefully
chosen and should be plumbed as shown. When following this diagram, the water fill procedure
becomes very simple and almost guarantees the removal of all air or prevents air locking problems.
Experienced hydronic heating installers may be able to eliminate some components but the inclusion
of these components guarantees installation and initial operating success.
5. The vessel is factory constructed with an “air trap” chamber at the top of the vessel, connected to the
1” pipe and arrangement shown on BX505.
6. The key mechanical components required include:
Expansion Tank – as a closed loop hydronic heating system, a minimal expansion tank is
required. This can be an air diaphragm tank as provided in the plumbing kit or a basic
“empty” tank where air is compressed at the tank top.
Inlet Temperature Gauge – recommended to observe the operation of the system.
Air Vent – install with the pressure relief valve as shown on drawing.
Inline Air separator – this can be installed ahead of the pump with the expansion tank
moved to this point. However, the vessel designed air trap and the piping arrangement
leading to the air bleeder.
Pressure Safety Valve – this is required and is furnished as a loose component with the
boiler unit itself. Failure to install the provided, 30 PSI, pressure relief valve as shown void
warranty and the CSA product listing. During purging there is a requirement to bleed out the
initial air within this 1” pipe leg by manually holding open the relief valve. Add the
necessary pipe extension to the relief valve to prevent water damage on this unit or
surrounding area.
Gate Valve/Drain Valve – these are for servicing and easy fill purposes.
Circulating Pump – depending upon system lift and system loop resistance, the proper
circulating pump is required to guarantee the minimum GPM flow as specified in
Specification Table.
Comment: Circulator pump can be in the outlet or inlet. Newer, higher quality pumps seem to
work better in the “supply” line, plus pumping away from the expansion tank is preferred.
7. To ensure safe boiler operation adequate system pressure must be maintained. Some expansion tanks
may have an integral regulator and “port” for water source hookup.
8. Depending upon water conditions, determine whether water additives are necessary.
9. Purge and fill water system. Do not allow the electric element to come on until the system is purged
and you have verified proper water circulation. If the pump is needed, jumper the two orange wires
in order to operate the pump directly from its own 120 volt source.
10. Purge each loop individually, one at a time.
11. Check for leaks.

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MECHANICAL INSTALLATION – DUAL HEAT
CAUTION
Electro Industries Inc. requires the use of dielectric isolation between the boiler vessel supply
and return piping when the boiler is plumbed using copper or any other dissimilar metal.
Damage to the vessel caused by galvanic corrosion voids Electro Industries’ warranty.
Reference drawing BX506
1. Unpack the Electro-Boiler. The safety relief and pipe fittings are packed within a small carton.
2. In most dual heat installations this Electro-Boiler is plumbed in parallel with an existing oil, gas, or
wood boiler. If piped in series, the Electro-Boiler is generally at the gas/oil outlet; but for wood
boiler systems, the Electro-Boiler must be on the inlet sides. The standby boiler cannot be operated
as “hot boiler”. This will defeat the Electro-Boiler. Rewire as required using the included standby
boiler interface (brown wires).
3. Standard hydronic hot water heating practices apply. This procedure assumes adequate piping size to
meet the flow requirements of the specific boiler model, expansion tank, pump, zones, etc. are
properly designed and installed.
4. The Electro-Boiler must be positioned with the vessel vertical. The water IN/OUT ports must be at
the top. The unit will not function properly with the vessel in a horizontal position.
NOTE: Mount at least 20 inches above the floor to allow element removal and service at the
bottom.
5. Typically this unit is wall hung next to the existing boiler.
6. Use the ¾” pipe fittings to install the safety relief valve and air vent. Add the necessary piping to the
safety relief valve so that water damages do not occur in the surrounding area.
7. Connect the “hot” water line from the fossil fuel boiler to the Electro-Boiler "inlet". Connect the
Electro-Boiler "outlet" to the main feed line. When facing the Electro-Boiler vessel, the "outlet" is on
the LEFT
NOTE: Wood applications, plumb so electric feeds the wood boilers.
8. If piping contains any "U" bend, an air vent may be required at the top.
9. When possible, isolating ball valves are recommended for easy servicing.
10. To ensure safe boiler operation and prevent element damage, the system should contain a pressure
regulator and an automatic water fill valve. Expansion tank may have an integral regulator and “port”
for water source hookup.
11. Depending on water conditions, determine whether water additives are necessary.
12. Purge and fill water system. Do not allow the electric element to come on until the system is purged
and you have verified proper water circulation. If the pump is needed, short out the two orange wires
in order to operate the pump directly from its own 120 volt source.
13. Check for leaks.

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ELECTRICAL HOOKUP
Reference drawing BH511
1. 240 Volt Heating Power – route and install the proper current carrying conductors from service
panel fuse or circuit breaker. See Specification Table and/or product nameplate for ratings. These
models contain built-in circuit breakers and meet the requirement for local disconnect for appliances
greater than 10 kW. Connection is at the circuit breaker terminals. If using single feed method,
single feed bus – order part number 5701.
Only copper wire is allowed.
CB1 is highest priority stage.
2. Grounding – copper conductor is required, size per NEC code relating to the current of each feed.
3. Circulating Pump – the two orange wires connected to a relay on the control board represent a
switch closure (10-amp maximum) to operate an external circulating pump motor. Voltage for the
pump must come from a separate source.
The pump is controlled as a direct function of the R and W input.
If this is connected with a standby boiler, generally the assumption is series plumbing with
the single pump. In this case, the R and W function will operate the pump whether in electric
or standby mode.
If a standby boiler installation has parallel plumbing with two pumps, field wiring and
controls will be necessary to properly operate (and typically check valve isolate) the standby
boiler self-contained pump from the system pump controlled by these two terminal screws.
4. Operating Thermostat – two types can be used. Connection is at the control board bottom.
Standard Mechanical – connect to “R” and “W”, bottom right. Set thermostat internal heat
anticipator to 0.2.
Floor Sensing Stat – connect to “R” and “W”, bottom right. Place slab sensor in the slab.
If needed, can connect thermostat “C” to boiler “C
NOTE: Power robbing/power stealing thermostat – if you have a power robbing or power stealing
thermostat, you must use the resistor included with the thermostat. Place this jumper between boiler
“W” and boiler “C”. If resistor is not used, intermittent boiler operation can be expected.
Comment: If zone valve or zone pumps see appropriate sections.
5. Load Management Interrupt Control – this Electro-Boiler series has been pre-wired and designed
for an external utility load management receiver connection. The control board lower left terminal
block marked BLU and BLU/WHT represent the two contact points, extend these wires to the utility
load control device. As shipped, this unit is only equipped for off-peak = N.C. logic. If reversed
logic is required, contact the factory for modification.
Optional – if load management is not used, simply keep the two blue wires shorted.
Optional – if the power company disconnects 240V for load control, contact factory for
drawing BH029 for special wiring requirements.
6. Outdoor Sensor (OT, outdoor reset control configuration EB-MX models only) – the loose OT
sensor bracket/probe needs to sense true outdoor temperature. Mount on an outside wall position that
will represent the most accurate outdoor temperature. If possible shade from direct sun rays.
If you have an EB-MS boiler and would like outdoor reset, order part number WFS25F.

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7. Zone Valves or Zone Pumps – see Zone Controller section for options.
WARNING
THE END SWITCHES FROM THE ZONE VALVES MUST BE AN ISOLATED CONTACT WITH NO
VOLTAGE PRESENT ON THESE WIRES OR SCREW TERMINALS. THIS IS VERY IMPORTANT
TO MAKE SURE THERE ISN’T ANY INTERFERENCE OR FEEDBACK BETWEEN THE
TRANSFORMER OPERATING THE ZONE VALVE SYSTEM AND THE TRANSFORMER WITHIN
THIS ELECTRO-BOILER PRODUCT. ONCE THIS HAS BEEN DETERMINED, ALL END
SWITCHES ARE SIMPLY PARALLELED WITH THE TWO WIRES GOING TO “R” AND “W”.
8. If this is a dual heat application with standby boiler, the 2 brown wires connect to the standby boiler
R and W or T and T. These 2 brown wires represent a contact closure to activate the standby boiler
during load control or when the front panel switch is in the “standby” position.
WATER ADDITIVES
1. Unless the source water is unusually poor and/or rust elements, additives are not required. It is
recommended the water source as shown on drawing BX505 comes through the household water
softener or use distilled water.
2. Impurities within a closed loop hydronics boiler are considerably less damaging than the typical
domestic water heater. In a closed loop electric boiler, the water impurities “boil out” and the
system essentially makes its own pure water. As a closed system, this “pure water” becomes the
operating mode. In the case of domestic water tank, there is always new water entering with new
impurities.
3. However, if additives are required, use the recommendations and source from your local
professional plumber, specializing in hydronics heating systems.
WATER FILL PROCEDURE
The following procedure applies to non-glycol or antifreeze and prepackaged plumbing kit and/or when
the system is plumbed exactly as shown on drawing BX505.
CAUTION
If the building supply pressure is connected directly to supply water ball valve without pressure
reducing regulator, user needs to make sure the pressure within the boiler loop does not exceed 30
PSI. Careful control of the supply water ball valve opening can take care of this. Also at steps 6
and 10, use caution to make sure the building water supply pressure does not “spike” the system.
1. Connect the temporary household water supply source (probably hose connection) to the "water
supply connection" input.
NOTE: If water supply connection is permanent, some local building codes may require
special anti-siphon check valve, RPZ check valve, or equivalent between the boiler fill
regulator and the domestic water source or the city water connection.
2. Connect a drain hose to hose bib, "drain valve".
3. Open "drain valve" and close "inlet gate valve" (between drain valve and boiler inlet).
4. Verify “top gate valve” is open.
5. Do not apply 240 heating power during water fill sequence.
6. Open “water supply valve” and open household water supply source.
7. Allow system to circulate, discharging through drain valve, for at least 15 minutes.
8. Put your ear against the metal pipe and listen for air bubbles. If the water flow is consistent and
quiet, the system is probably purged and water filled.
9. Close the "drain valve". Open the "inlet gate valve".
10. The cold system pressure at the gauge should be approximately 10 to 14 PSI.

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11. Close “water supply valve” and disconnect water supply.
12. Optional – energize circulating pump during this fill operation. The water pressure from the
household system and as plumbed should typically flow through the circulating pump without the
pump running.
COMMENT: Purge one loop at a time.
CONTROLLER SETUP
Staging/modulating jumper, red dial switch, front panel:
Non-outdoor reset – simply set the “knob” to the desired outlet temperature shown here and on the
front panel decal.
This control strategy is accomplished via disconnecting the outdoor sensor and performing a power
reset to the boiler (low voltage power cycle).
Outdoor reset – the temperature decal will relate to the OT 0° set point and the “knob” numbers
coincide with the curves below. High and low mass also relate to the ramp-up water temperature
starting point, as shown. Select the high or low mass with the rate of temperature rise based on
outdoor temp (OT).
Comment: The WF-ANZ* test set allows field change of the base temperature start point.
This control strategy is accomplished via connecting the outdoor sensor and performing a power
cycle on the boiler (low voltage power cycle).
The front panel temperature selection number coincides to the curves below. This temperature value
shown on the front decal is actually the supply water at 0° outside.

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Staging/Modulating Jumper
The control board on the Midsize Series boiler is a universal controller with the capability of interfacing
with many different models of TS Electro boilers.
The correct setting of this jumper is determined on the model of the boiler you are
working with.
If you’re working with an EB-MX-**, this should be set to “MODULATE”.
If you’re working with an EB-MS-**, this should be set to “STAGING”.
Circulator pump mode – as factory set, the circulator pump is controlled directly from the “W” input
terminal. In this setup the circulator pump continues during load control interrupt (or optional remote
standby switch). There is a provision within the controller board (inside) to allow the circulator pump to
not operate during load control interrupt.
On the inside control board, just above the two
bottom terminal blocks, is a small pin jumper
arrangement. The black “device” sets up the pump
mode. Just below this pin jumper arrangement are
W and L lettering. When the two pin shorting
device is in the W position, the pump is a direct
function of R to W input. When the two pin jumper
is in the L position, the pump is interrupted during a
load control.
WARNING
THIS SHORTING DEVICE MUST BE IN ONE OF THE TWO POSITIONS FOR THE CIRCULATOR
PUMP TO PROPERLY OPERATE.

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OPERATIONAL TIPS
Normal/Standby Switch
If this system does not have a standby operating (gas or oil) boiler, this
switch must always be in the “normal” position.
To activate standby boiler, simply position front panel switch to “standby”.
Monitor Lights, Front Panel
190°F AUTO RESET LIMIT, red – this will only
illuminate when the vessel hi-limit opens due to
excessive high water temperature. This hi-limit is
self-resetting.
BOILER POWER, green – basically this is
illuminated at all times. It represents 24-volt power
source, good fuse, controller logic is operational,
and a good outlet sensor. If the outlet sensor is
inoperative, incorrectly wired, or malfunctioning;
this green monitor LED should be in the blinking or
pulsing mode (see Troubleshooting section).
ELECTRIC MODE, amber – when illuminated the
system is in the electric mode. If it is not
illuminated the utility load control receiver is in the
interrupt or on-peak mode. If there is an optional or
remote standby switch, the status of the standby
switch is also monitored by this amber LED.
THERMOSTAT CALL, red – indicates a remote
switch closure (t-stat or zoning end switch) is
closed between terminals R and W.
Inside Controller Board
STAGES, red – these four LED’s indicate which electric element stages are on and active.
Flow Switch Statement
A flow switch is not included with the boiler. However, one can be added to the LMC circuit. Simply
place the field provided flow switch in series with this circuit.
NOTE: The “L/W” (J3) jumper must be in the “W” position.

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Manual Reset, Hi-Limit
At the top of the vessel there will be either two or three surface mount hi-limits preset at 205° F. There is
no light indicator associated with these safety hi-limits. Also these 205° F safety limits break the L2
current carrying 240-volt wire going to the elements. Reset involves locating a small shiny lever or metal
tab protruding on the side of the black safety limit base. This small tab is pressed inward approximately
1/8” to “snap in” the contacts.
CAUTION
The wires and screws have 240-volt potential and can be dangerous. Turn off circuit breakers
before investigating or attempting to reset the 205° F safety limits.
Internal Fuse
The fuse on the controller board protects the transformer secondary, external items connected to “R”, and
the circuit board itself. Replace with 5-amp fast blow, mini-automotive fuse or equivalent.
Stat Heat Anticipator - If it is a mechanical stat, verify heat anticipator has been set at Ø.2 (non-zone
system).
System Pressure
The side press/temperature gauge should be at approximately 10 to 16 PSI at room temperature water and
should not rise more than approximately 4 PSI at the operating or hot water temperature. If the pressure
change is more than approximately 4 PSI, the expansion tank is too small or there is a problem with the
expansion tank piping, expansion tank itself.
Cold slab, outdoor reset and temperature sensing prevent full boiler on – by adding a temporary
jumper between the lower W screw terminal and the upper left “E” tab, all temperature sensing functions
are bypassed and the control board will step in all the stages.
CAUTION
This jumper shall not be a permanent function, jumper needs to be removed after slab is
approaching normal temperature.
Standby Switchover, SOT Timer
This plug-in option device allows a selection from 40 to 80 minute thermostat operating time for
automatic switchover to standby boiler. Order part number SOT-1.
WARNING – HIGH VOLTAGE
MUST SHUT OFF HIGH VOLTAGE BEFORE
ATTEMPTING TO RESET.

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Replacement Parts
WFSB Water sensor, 3 ft.
WFS25F Outdoor sensor (OT)
EB5623 Controller, temperature sensing
UFUSE0442 5-amp, fast blow mini-automotive fuse
4038KIT Triac switch module
5127 Heating relay
5535 Safety hi-limit, manual, 205°
5537 First hi-limit, auto-reset, 185°
5453 Relief valve, 30 PSIG
5456A Gauge press/temperature
5652 60A SQ D circuit breaker
5650 30A SQ D circuit breaker
EB5526 Electric element, 240, 5 kW
5541 Transformer, 24V, 40VA

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TROUBLESHOOTING/REPAIR HELPS
1. This WarmFlo controller contains several interference suppression components, but as an electronic
logic product, unpredictable and unusual transients or interference may sometimes cause strange
results. If the WarmFlo controller is “acting strange”, one immediate step would be power down
reset. Simply turn off boiler power or breaker number 1, when the green LED goes out, count to 1Ø,
and re-energize power supply.
2. Inoperative temperature sensor, if the internal program can detect a bad sensor (shorted, open wire,
etc. – not necessarily bad value) the front panel green LED will be pulsing. By checking the pulsing
pattern, the appropriate sensor can be identified.
-OT sensor – 1 blink every second
-ST sensor – 2 blinks every second
-Both bad – 3 blinks every second
3. The temperature sensor can be further evaluated with diagnostic program from standard PC or WF
Analyzer software. This includes the ability to “fool” the sensor or set in an offset for various
troubleshooting purposes. This software disk comes with a special cable needed for PC or Palm
hookup.
-WF-ANZ* – Handheld/Analyzer
-ET-SOFT-HTG – PC software disk and cable
4. The terminal blocks for control wire hook-up are designed for a wire insertion and screw clamp
down. If there is no wire connected and the screw is loose, the screw may not necessarily make a
good electrical contact to the inside components. Example – if you are jumpering the thermostat
terminals without thermostat wire connection or if you are attempting to measure voltage on the
screw head, you may get erroneous or unpredictable results if the screw is not tightened down.
5. The outdoor sensor (OT) must be sensing the actual outside temperature for this controller to
correctly operate (if you’re using the outdoor reset configuration). Do not simply leave the outdoor
sensor “hang in the room” and attempt to run this system.
6. Temperature sensing bypass – the inside control board, left side, contains a “E” tab which can be
used to directly step in the heating stages and in essence bypass the temperature sensing and control
functions. The “E” tab has the highest priority and overrides all temperature sensor functions. In
other words, when jumpering from W to E all four stages are hard on. Note: Verify pump is
operating prior to using the E terminal. Since activating this E terminal causes full electric element
output, this function should only be used to verify all stages or troubleshoot proper 24Ø current at
each element.
7. Use general heating system logic information and basic understanding of the terminal block wiring
functions measure various voltage points to determine proper operation.
8. Acquiring the PC software or Palm with serial port hookup cable is a positive tool for understanding
and troubleshooting the WarmFlo controller. Either test set device can display all temperatures, real
time evaluation of WarmFlo functions and provide temperature offsets for assimilating winter
conditions.
Sensor Temperature Calibration - Both remote sensors are digital electronic and factory calibrated.
Normally these do not require field calibration or verification. However, if sensor temperature error is
determined, there are two field calibration techniques. Proceed with extreme caution.
1. The outdoor sensor (OT) can be calibrated with ice (32F). This is not a checking temperature
situation. If you proceed with this function, the sensor automatically goes to 32F. Notice a small
push button next to the sensor terminal block, with the sensor at 32F, push and hold for
approximately ten seconds. When the green LED next to the fuse “blinks” at you, release and now
the outdoor sensor is set at 32F.
2. Use PC or Palm software to calibrate sensor. See other paragraphs.

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OPERATIONAL INFORMATION
In order for the installer to completely understand the WF II functions and operational sequence it is
recommended to thoroughly read and understand the information below. This knowledge can help in
determining settings that can be set according to the end customer’s needs.
WarmFlo Analyzer (WF-ANZ*) or PC software (ET-SOFT-HTG) – can be used to verify
temperatures.
Warning, field reprogramming – within WarmFlo II internal logic and non-volatile memory, it can
detect whether it is operating from one of the above factory pre-programmed chips or if it has been
modified (reprogrammed) with PC software or Handheld. Once the user or field technician has
downloaded (save), from that time forward the WarmFlo II physical control board is no longer governed
by the above table, or the chip code written on the plug-in chip, etc. In other words, power up/power
down, reset, or removing and re-plugging the chip does not affect any altered reprogrammed functions. It
is smart enough to know it is no longer the original chip and that specific physical board, from this time
forward, must be under the control of the PC software/Palm.
Normal Heating Operation – whenever the WarmFlo screw terminal “W” is at 24 volt (with reference to
“C”), the WarmFlo controller begins turning on the elements and automatically controls the water
temperature as sampled by the ST sensor. However, if added heat is not required, no element power is
used.
Depending upon the Electro-Boiler model, there will be various electrical stages, all under the control of
WarmFlo. Except for the first 4.5 kW element, the remaining stages operate as steps 2, 3, and 4 from the
WarmFlo controller.
MODULATE Setting (J8) Description: Step 1 (first 4.5 kW) is pulse modulated through the triac
(approximate 1Ø second cycle) based upon the WarmFlo controller automatic requirement. Steps 2, 3,
and 4 are turned on and off with relays. However, steps 2, 3, and 4 are only used when required by the
WarmFlo water temperature calculations. Stage 1 may not necessarily remain at 100%, but is modulated
downward to meet the requirements of the water sensor, etc.
STAGING Setting (J8) Description: Steps 1, 2, 3, and 4 are turned on and off with relays. Steps 1, 2, 3,
and 4 are only used when required by the WarmFlo water temperature calculations.
The time between stage turn on depends upon where the controller logic memory was after the last
thermostat call or following a power up reset condition. The longest time between staging is from the
power up condition because the logic does not have a history of previous thermostat calls. Once the
history of several thermostat calls has been established within memory, it automatically returns to the last
active stages, with an approximate 5 seconds between stage turn on. However, during power up the logic
needs to search a number of times before it finally declares the next stage.
A clamp-on amp meter at the service input can be used to “visualize” the stage 1 modulation and/or stage
2, 3, and 4 functions.
Delay, transfer from standby to electric – if the unit was operating in SB for more than 1 minute, the
follow-up transfer back to electric engages a 2-minute delay before any of the electric stages are
activated. The pump will react to the call for heat, but the elements will stay off for 2 minutes in order for
the pump to cool down the standby boiler vessel.