Immersion Heating Elements; Start-Up Procedure; Thermal Expansion; Filling The Water Heater - Lochinvar Commercial Electric Water Heaters Installation And Service Manual

IMMERSION HEATING ELEMENTS

FIG. 14 Immersion Heating Element
WARNING:
HAZARD OF ELECTRICAL SHOCK - Before
opening the access panel to remove or service the
immersion heating elements, make sure the electrical
supply to the water heater is turned "OFF". Failure to
do this could result in death, serious bodily injury or
property damage.
The heating input to this commercial electric water heater
is provided by low watt density immersion heating
elements. The heating elements are constructed from a
copper sheath with a tin plate on the exterior surface.
Individual element blades are mounted on a hex-head
screw-in mounting flange. The element flange mounts into
a 1" NPT threaded connection welded to the storage tank.
The hex-head screw-in mounting flange seals to the tank
with an "O" ring gasket at the base of the threaded portion
of the flange. The tank flange has a matching recess for the
"O" ring gasket to insure a proper water tight seal. The "O"
ring element gasket must be replaced with a new gasket
when an element is removed for inspection, cleaning or
replacement.
DANGER
HAZARD OF ELECTRICAL SHOCK - Full power is
present whenever the cabinet door is opened and
main power is turned "ON".

START-UP PROCEDURE

Never operate the heating elements without being certain
the water heater is filled with water and a temperature
and pressure relief valve is installed in the relief valve
opening on top of the heater.
Full power is present whenever the cabinet door is
opened.

THERMAL EXPANSION

Many water systems are equipped with pressure reducing
valves, check valves or back flow preventers which may
cause the water system to be closed. As water is heated, it
will expand in volume due to thermal expansion. The
system must make allowance for this expansion. If an
expansion tank is not provided in the system, water
pressure may increase to the point where the water heater's
temperature and pressure relief valve opens to relieve the
excess pressure. The temperature and pressure relief valve is
not intended for the constant relief of thermal expansion.
This is an unacceptable condition and must be corrected. A
properly sized expansion tank is typically installed in the
potable water system to relieve the pressure built up by
thermal expansion of heated water. Consult your local
plumbing contractor and plumbing wholesaler for
assistance in properly selecting an expansion tank for your
system.
As the water heater operates, there may be noises generated
by the expansion and contraction of the metal parts of the
water heater and related piping. These noises may occur
during periods of heat up or cool down. They do not
represent harmful or dangerous conditions.

FILLING THE WATER HEATER

1. Insure that the electrical power to the water heater is in
the "OFF" position. If the power disconnect point is out
of sight, lock it in the open ("OFF") position and tag to
prevent unexpected application of power.
2. Close the water heater drain valve(s).
3. Open a nearby hot water faucet to allow the air in the
system to escape as the tank fills.
4. Fully open the cold water inlet valve to the water heater
to begin filling the heater and piping.
12
DANGER