Electro Industries EB-MS-15, EB-MS-20, EB-MX-10, EB-MX-15, EB-MX-20 Installation Manual

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
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

SUGGESTED MINIMUM

SERVICE CLEARANCE

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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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