Hubbell Electric Heater T120-20 Installation Manual

INSTALLATION, OPERATION AND

MAINTENANCE MANUAL FOR

ELECTRIC HEATER COMPANY

COMMERCIAL INDIRECT

POWERED WATER HEATER

BASE MODEL “ T ”

Edition 2011

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. Tank is to be completely filled with water and all air is to be vented before energizing.

2. Due to the rigors of transportation, all connections should be checked for tightness before

heater is placed in operation.

3. Safety relief valve must be installed in tapping provided.

4. 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, turn the charge or
ground the circuit before performing any maintenance or adjustment procedure.

5. The unit is designed to operate at pressure not more than 150 psi.

6. 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 regulation,
tools, equipment, and methods necessary for safe installation of an electric resistance
water heater. If questions regarding installation arise, check 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 4

II INSTALLATION 6
III SCHEDULED MAINTENANCE AND OPERATION 8
IV TROUBLESHOOTING 10

V SERVICING AND REPLACEMENT OF PARTS 11
VI MISCELANEOUS CHARTS AND FORMULAS 19

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SECTION I - GENERAL DESCRIPTION AND CONSTRUCTION

GENERAL DESCRIPTION

This book describes a packaged boiler water powered indirect water heater that is a stationary,
self-contained unit. The complete assembly on a standard unit consists of the storage tank,
immersion heating coil, 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, wired,
tested, and ready for electrical and plumbing service connections.

CONSTRUCTION

TANK

The standard storage tank is constructed of steel and internally lined with specially formulated
Hydrastone cement to a ½-inch minimum thickness. The tank is designed for a maximum
allowable working pressure of 150 psi (300 psi TP).

TANK CONNECTIONS

The heater is supplied with separate cold water and hot water connections. Water entering the
cold water inlet is deflected by means of a baffle within the tank. The hot water outlet includes a
built in heat trap to prevent hot water from radiating out from the heater. A ¾-inch FNPT
connection is located on the side of the heater for mounting a combination safety temperature
and pressure relief valve. An overflow line should be installed from the relief valve outlet to a
floor drain. A ¾-inch GHT connection is supplied for draining. See drawing for locations and
sizes.

OUTER SHELL AND INSULATION

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.

HEATING COIL

The water heater is supplied with a high quality,
factory installed, high efficiency, single walled,
copper finned heating coil designed for a maximum
working pressure of 150 psi. The tubing is installed
in a heavy-duty fabricated steel head with threaded
NPT connections. Each assembly is fastened to a
corresponding tank flange using a gasket and hex head steel bolts and
nuts.

CONTROL THERMOSTAT

The water heater is supplied with an immersion thermostatic switch. The
thermostat can be adjusted through a range of 120° - 140° F.

OPTIONAL BACK-UP ELECTRIC HEATING SYSTEM
Back-up Electric Heating Element

The water heater may be supplied with an electric immersion heating element assembly(s).
Each assembly is fastened to a corresponding tank flange using a gasket and four (4) 3/8-16 x 1­inch long hex head steel bolts and nuts. See drawing for voltage and power ratings.

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Control Thermostat

The water heater may be supplied with either a surface mounted or immersion thermostatic
switch to control the back-up electric heating system. See drawing for specific details. The
surface mounted thermostat can be adjusted through a range of 110° - 170° F. The immersion
thermostat can be adjusted through a range of 100° - 190° F. Both thermostats are adjustable
with a flat tip screwdriver.

Surface Mounted Thermostat Immersion Thermostat

Temperature High Limit Switch

As a safety device, either a surface mounted high temperature cut-off switch with manual reset,
factory set at 190° F, or an immersion high temperature cut-off switch with manual reset,
factory set at 180° F, may be provided. In the event of an over-temperature condition, the
thermostat will disengage the power from the back-up electric heating system. The high limit
must be manually reset thereafter to restart the heater.

Manual Reset

Surface Mounted High
Temperature Cut-Off Switch Immersion High Temperature Cut-Off Switch

Double Wall Heating Coil

A Double Wall Heat Exchanger consists of two copper tubes,
one inside the other, wound into a coil. The outer tube is
soldered into the fitting that mates into the tank. The inner
tube is soldered into the fitting that mates with the hot water
supply. The gap between the two tubes is open to the air,
allowing visible detection of any leaks, as well as preventing
any leaks from mixing into the other liquid.

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SECTION II – INSTALLATION

WARNING / CAUTION

DO NOT TURN ON THE BOILER WATER SUPPLY to this equipment until heater is
completely filled with water and all air has been released. If the heater is NOT filled with
water when the power is turned on, damage to the heating coil may result.
For protection against excessive pressures and temperatures, local codes 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 FURNISHINGS OR PROPERTY.

WATER HEATER PLACEMENT

1. Place the heater on a solid foundation in a clean, dry location nearest to the point of

most frequent hot water use. If the heater is to be raised off the floor, the entire bottom
of the heater should be supported by a solid surface.

2. The water heater should be protected from freezing and waterlines insulated to reduce

energy and water waste.

3. Leave a minimum of 18” clearance for element withdrawal, if necessary.

INSTALL THE HEAT EXCHANGER COIL

1. Remove the access panel.

2. Apply the included o-ring lubricant to o-rings.

3. Insert the o-rings into the grooves on the plastic o-ring housing.

4. Insert heat exchanger and align holes in cover plate with holes in flange.

5. WARNING: Plastic o-ring housing must be properly installed. Failure to do this

will void the warranty.

6. Insert and secure the bolts to the nuts one at a time in the following manner:

• Place the nut behind the flange opening.

• Hold the nut in place with one hand – insert the bolt with washer with the other.

• Thread the bolt through the washer and into the nut and tighten.

• NOTE: Be sure to place bolts in all of the openings.

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