Hubbell BWP Series User manual

INSTALLATION, OPERATION AND
MAINTENANCE MANUAL FOR
INDIRECT FIRED WATER HEATER
ELECTRIC HEATER COMPANY
BASE MODEL “BWP”
Edition 2019

2
HUBBELL
ELECTRIC HEATER COMPANY
P.O. BOX 288
STRATFORD, CT 06615
PHONE: [phone]
FAX: [phone]
INTERNET: http://www.hubbellheaters.com/
-- IMPORTANT --
Always reference the full model number and serial number when calling the factory.
WARNING / CAUTION
1. FLUIDS UNDER PRESSURE MAY CAUSE INJURY WHEN RELEASED.
Always shut off all incoming and outgoing valves and carefully decrease all trapped
pressures to zero before opening any covers, piping or gauge connections, etc.
2. HOT WATER OR HOT SURFACES CAN CAUSE SEVERE BURNS.
Wear safety goggles and protective gloves when carrying out maintenance procedures
involving the heater and/or when removing and accessories from the heater. Shield
your eyes and body to protect from spray when opening a relief valve.
3. Tank is to be completely filled with water and all air is to be vented before energizing.
4. Due to the rigors of transportation, all connections should be checked for tightness before
heater is placed in operation.
5. Safety relief valve must be installed in tapping provided.
6. KEEP AWAY FROM LIVE ELECTRICAL CIRCUITS.
Do not perform any maintenance, make any adjustments, or replace any components
inside the control panel with the high voltage power supply turned on. Under certain
circumstances, dangerous potentials may exist even when the power supply is off. To
avoid casualties, always turn the power supply safety switch to off, or ground the circuit
before performing any maintenance or adjustment procedure.
7. Generalized instructions and procedures cannot anticipate all situations. For this reason,
only qualified installers should perform the installations. A qualified installer is a person
who has licensed training and a working knowledge of the applicable codes and
regulations, tools, equipment, and methods necessary for safe installation of an indirect
fired water heater. If questions regarding installation arise, check with your local
plumbing and electrical inspectors for proper procedures and codes. If you cannot obtain
the required information, contact the company.

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SECTION
TITLE
PAGE No.
I
GENERAL DESCRIPTION AND CONSTRUCTION
5
General Description
General Operation
Construction
II
INSTALLATION
9
Codes and Regulations
Water Heater Placement
Piping Installation
Electrical Installation
Filling the Heater
III
OPERATION
15
Startup
Shutdown
IV
SCHEDULED MAINTENANCE AND SERVICING
16
Recommended Maintenance
General Maintenance
V
TROUBLESHOOTING
18
VI
MISCELANEOUS CHARTS AND FORMULAS
19

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MODEL BWP -
OUTLINE DIMENSIONS

5
SECTION I
GENERAL DESCRIPTION AND CONSTRUCTION
GENERAL DESCRIPTION
This manual provides a complete description, as well as installation, operation, troubleshooting,
maintenance, and servicing procedures for a fully packaged indirect fired water heater. This
heater provides potable hot water for various functions. It is a permanently installed, stationary,
self-contained unit with automatic operating controls.
The complete assembly on a standard unit consists of the storage tank, a brazed plate heat
exchanger (piped to the storage tank), a circulator pump, and an ASME rated combination
temperature and pressure safety relief valve. Optional equipment may be supplied with your
unit. Please consult the product drawing for details specific to your assembly. The unit is
factory assembled, insulated, jacketed, piped, tested, and ready for service connections.
GENERAL OPERATION
The BWP model operates using boiler water as its energy source for heating potable hot water.
The BWP series can provide potable hot water up to 180°F. Therefore, the supplied boiler
water must be within the range of 150°F to a maximum of 220°F and must be at least 5° above
the potable water temperature desired from the water heater storage tank outlet.
Boiler water and potable water enter the plate heat exchanger, in a counter flow pattern, where
heat transfer takes place from the boiler water to the potable water. The heated potable water
exits the heat exchanger and enters the storage tank. An integrally mounted control panel
provides a central location for electrical power connections.
How it Works
1. When there is a demand for hot water consumption, hot water exits from the top of the
storage tank and is replaced by cold water entering the bottom of the tank. When enough
cold water enters the storage tank to lower the stored hot water temperature below the
desired value, the control circuit closes creating a call-for-heat, which energizes the
circulating pump and boiler water control valve.
2. When the circulating pump and control valve are energized, the pump circulates domestic
water from the storage tank through the potable side of the heat exchanger plates. Boiler
water flowing through the opposing side of the heat exchanger plates heats the potable
water before it returns to the storage tank.
3. When the stored water temperature increases above the desired value, the control circuit
opens and the circulating pump and boiler water control valve are de-energized. With
the pump no longer running, no more potable water flows from the heat exchanger into
the storage tank.
CONSTRUCTION
The water heater components and operating controls are factory selected, sized, piped, and
tested to ensure reliable operation. See applicable drawing supplied with water heater for
specific details.
TANK CONNECTIONS
The storage tank is constructed of all welded carbon steel, and internally lined with specially
formulated Hydrastone cement to a ½-inch minimum thickness for superior protection and tank
longevity. The tank is designed for a maximum allowable working pressure of 150 psi (225 psi
TP).

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Temperature and Pressure Relief Valve
A combination safety temperature and pressure relief valve is installed at the top of every
storage tank. An overflow line (either 1-inch or ¾-inch connection) should be utilized from the
relief valve outlet to a suitable floor drain. Refer to Section II, Piping Installation, Figure I,
Temperature and Pressure Relief Valves section of this manual for additional information.
Outer Shell, Insulation, and Supports
The tank is encapsulated in 2-inch thick polyurethane foam insulation. The insulation is
protected by a high impact non-corroding colorized composite protective jacket. The entire
vessel is supported on heavy-duty integrally welded steel supports for sturdy floor mounting.
BRAZED PLATE HEAT EXCHANGER
The water heater is supplied with an
efficient high quality Brazed Plate
Heat Exchanger. The heat
exchanger consists of individual
embossed plates contained between
end plates. The serially arranged
plates are brazed together forming a
sealed pack with flow gaps between
each plate. The boiler water and
potable water flow through every
other flow gap in opposite
directions for efficient heat transfer.
The number and arrangement of the
heat exchanger plates depends on
the specific requirements of each water heater application. Refer to the separate component
O&M manual for a complete functional description as well as detailed information on the
construction and maintenance of the brazed plate heat exchanger.
BOILER WATER COMPONENTS
Boiler Water Control Valves
The standard BWP model includes a 2-way Modulating Control Valve. Refer to the
technical drawings provided with the heater to determine which valve type is utilized.
Control Valve, 2-Way
A high quality electrically operated control valve is installed in the
boiler water line upstream of the heat exchanger. This
sophisticated electronic device controls the flow of boiler water to
the heat exchanger providing the precise amount of boiler water to
produce the desired potable water output temperature. This valve
receives an electrical position signal from the panel mounted
temperature controller to maintain the pre-set water temperature.
The control valve is installed in such a way that in the event of
reaching the potable water high limit temperature, power is
removed from the control valve allowing it to automatically close.
The closed valve blocks the flow of boiler water to the heat
exchanger, thereby preventing excessively high temperatures of the potable water. Refer to
the separate component O&M manual for a complete functional description as well as
detailed information of the 2-way valve.

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POTABLE WATER COMPONENTS
Thermocouple
A thermocouple is mounted in the storage tank. That element is wired to the panel mounted
temperature controller for monitoring and control of the desired water temperature. See
Control Panel components for additional detail.
Temperature and Pressure Safety Relief Valve
A temperature and pressure Safety Relief valve is
provided for installation in the potable water line
downstream of the heat exchanger.
Circulator Pump
A recirculation loop is used to maintain the
necessary flow of potable water from the storage tank through the heat exchanger. This loop
recirculates the potable water via a circulator installed between the heat exchanger inlet and
the storage tank. The circulator runs any time the system initiates a “call-for-heat.” For
more information regarding the circulator pump see included supplemental material from the
pump manufacturer.
Strainer
A cast bronze ‘Y’ strainer with 20 mesh stainless steel screen protects the potable water
controls and the passages within the plate heat exchanger from dirt and debris in the water
supply.
CONTROL PANEL COMPONENTS
Control Panel Enclosure
A painted steel NEMA 1 enclosure houses the main electrical control elements.
On/Off Switch
A lighted toggle switch is mounted through the enclosure door and is utilized to turn on
power to the unit.
Temperature Controller
A temperature and process controller is configured to control the
boiler water control valve with input from a thermocouple mounted
in the storage tank. The controller is mounted through the enclosure
door to allow full access to the user interface. Refer to the separate
component O&M manual for a complete functional description as
well as detailed information.
High Limit Thermostat
The water heater is supplied with an immersion thermostatic switch that is installed and
wired at the factory. The immersion thermostat can be adjusted through a range of 100°-
190°F and is typically set 10°F above the panel mounted high limit set point. The thermostat
is adjustable with a flat tip screwdriver.
Fused Low Voltage Transformer
A fused low voltage transformer is supplied prewired within the control panel. This is used
to step down higher voltages to 24-volts for the control circuit.

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MISCELLANEOUS COMPONENTS
Dial Temperature and Pressure Gauge
A combination temperature (70°-250°F) and pressure (0-200 psi)
gauge with a 2½-inch dial may be installed within the potable and
boiler water inlet and outlet piping for local indication.
OPTIONS
The following optional features may be included in your water heater. Reference included
drawing specific to your heater for further details.
Single Solenoid Safety System
A single solenoid safety system closes the water supply to the control valve should the
temperature in the tank reach the high limit set point.
Control Valve, 3-Way
The control valve is a motorized 3-way characterized control valve that regulates the flow of
boiler water to the heat exchanger, providing the precise amount of boiler water to produce
the desired potable water output temperature. This valve receives an electrical position
signal from the panel mounted temperature controller, directing excess boiler water flow
around the heat exchanger and directly to the boiler water outlet piping.
Isolation Valves for Clean-in-Place Heat Exchanger Maintenance
Depending on the water quality and operating temperature, scale can form during operation
and will continue to accumulate inside the heat exchanger. If non-damaging water
conditions are particularly poor, it may be necessary to outfit the heat exchanger piping with
isolation valves to utilize Clean-in-Place practices for heat exchanger maintenance.
Double Wall Brazed Plate Heat Exchanger
Depending on the application a Double Wall Brazed Plate Heat Exchanger may be required.
Ultimately a double wall configuration differs from a single wall configuration by utilizing a
gap of air between the plates to prevent cross contamination of fluid streams in the event of an
internal leak within unit.

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SECTION II
INSTALLATION
WARNING/CAUTION
CODES AND REGULATIONS
This equipment must be installed in accordance with all appliance markings, the instructions
included in this manual, and any supplemental instructions provided. This equipment must
also be in compliance with any installation regulations enforced in the local area where the
installation is to be made. These must be carefully followed in all cases. Authorities having
jurisdiction must be consulted before installation. In the absence of such regulations, the
installation must be in accordance with the latest edition of the applicable state and local
mechanical and plumbing codes. The storage tank conforms to the current edition of the
ASME Boiler and Pressure Vessel Code Section IV, and the plate heat exchangers conforms
to the current edition of the ASME Boiler and Pressure Vessel Code Section VIII.
For protection against excessive pressures and temperatures, local codes may require the
installation of a temperature-and-pressure (T&P) relief valve certified by a nationally
recognized laboratory that maintains periodic inspection of production of listed equipment of
materials, as meeting the requirements for Relief Valves and Automatic Gas Shutoff for Hot
Water Supply Systems. ANSI Z21.22-1971. THE CUSTOMER IS RESPONSIBLE TO
PROTECT PROPERTY AND PERSONNEL FROM HARM WHEN THE VALVE
FUNCTIONS.
All water heaters have a risk of leakage at some unpredictable time. IT IS THE
CUSTOMER'S RESPONSIBILITY TO PROVIDE A CATCH PAN OR OTHER
ADEQUATE MEANS, SO THAT THE RESULTANT FLOW OF WATER WILL NOT
DAMAGE PROPERTY.
Never operate unit in excess of design conditions.
The tank should be fully drained in the event the incoming boiler water is shut off and if there is
danger of freezing.
WATER HEATER PLACEMENT
Checking Equipment Before Installation
Inspect the unit completely upon receipt from the freight carrier before signing the bill of
lading. Inspect the heater and all accompanying parts for signs of impact or mishandling.
Verify the total number of pieces shown on packaging slips with those actually received.
Contact the freight carrier immediately if any damage or shortage is detected.
Handling and Locating the Water Heater
WARNING: Use industry standard safe rigging methods when attempting to lift or move
this product. Failure to follow industry standard safe rigging methods (such as the use of
straps and spreaders bars when lifting the water heater skid assembly) can cause
uncontrolled tipping or even dropping of the water heater, resulting in property damage,
personal injury, or even death.
1. Place the heater on a solid foundation in a clean and dry location. This location
should be as close as possible to the point of most frequent hot water. Additionally,
the location chosen should be near to boiler water and/or electrical power as practical.
2. If the heater is to be raised off the floor, the entire bottom of the heater should be
supported by a solid surface.
3. Verify that the system utilities are adequate to meet the water heater requirements as

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specified in this manual and/or other applicable appliance markings.
4. Unit should be level to permit proper drainage should any water connections leak. A
suitable drain would be capable of accepting hot water discharge (at least 210°F) from
the water heater temperature and pressure relief valve.
5. This water heater is suitable for indoor installation only and must not be subject to
freezing.
6. When the water heater has been placed in its final location, remove all shipping
supports and bracing.
Service Clearances
A minimum service clearance of 18” is recommended on all sides and above the water heater
to facilitate easy access for inspection and service of installed components. Optional
equipment may increase the clearance requirements.
Also allow sufficient space for installing and servicing connections such as building water,
electrical, pump, boiler water, heat exchanger, and any other auxiliary/optional equipment.
PIPING INSTALLATION
IMPORTANT: The most effective means for preventing deterioration from accelerated
corrosion due to galvanic and stray current is the installation of dielectric fittings/unions.
The installation of these fittings is the responsibility of the installing contractor.
IMPORTANT: If two or more water heaters are piped in parallel, it is critical that the
piping systems are balanced to assure that the combined capacity is realized. It is
recommended that reverse return piping is utilized in multiple-unit installations.
CAUTION: DO NOT use galvanized pipe or fittings or steel pipe or fittings when making
waterside connections. Use only non-ferrous waterside materials.