Installation Guide

SERVICE
Electric Tankless Water Heater • 27
5
Remove the thermistor by
turning it counter-clockwise
with a 1/2-inch open end
wrench.
6
Install the new thermistor in
the opening by turning it
clockwise with a 1/2-inch
open end wrench.
□ Make sure that the O-ring is
in place before you install the
thermistor.
□ Tighten the thermistor hand
tight, then carefully tighten
it with a wrench until it is
seated. Do not overtighten.
7
Plug the thermistor’s wires
into the control board. The
proper loca on is shown in one of the
fi gures on page 26.
8
Return the water heater to
service. To do so, follow the
instructions in “Returning the
Water Heater to Service,” page 28.
Draining the Water
Heater
WARNING!
• Working on an energized circuit
can result in severe injury or
death from electrical shock. Turn
power off.
• Some models are connected to
more than one branch circuit.
Disconnect all branch circuits
before servicing unit.
• Check wires with a non-contact
circuit tester to make sure power
is off . When you are fi nished,
be sure all covers are secured to
reduce the risk of fi re and electric
shock.
Draining the Water Heater
1
Confi rm that power is off by
checking the wires with a
non-contact circuit tester.
2
Open a nearby hot water
faucet and run the water until
it is cool.
WARNING! Be sure the
water runs cool before
draining the water heater to
reduce the risk of scalding.
3
Close the inlet valve to the
water heater, but leave the
hot water faucet open to
relieve pressure.
4
Remove the heater’s cover,
then place a bucket under the
water heater to catch any
water that spills.
NOTICE: If you have a two- or four-
chamber model, you must unplug the
cover’s ribbon cable from the control
board. When you plug it back in later,
it must be oriented correctly. We
recommend marking the connector
and board with a marker. You will then
be able to align the marks. See also
Figure 5, page 14.
• If you have a point-of-use water
heater, go to step 5.
• If you have a two- or four-chamber
water heater, go to step 6.
5
Point-of-use water heaters
only:
Drain the point-of-use water heater:
A.) Remove both screws which secure
the top plate to the water heater.
(See Figure 25.)
Figure 25.
Top View of Point-of-Use Model
Top Plate
Screws
B.) Lift and remove the top plate.
(Removing it will protect if from
damage.)
C.) Cover the top of the water heater
with heavy towels (to prevent
water from dripping through the
openings).
A er the towels are in place,
disconnect the inlet and outlet
water lines from the water heater.
D.) Remove the hea ng element as
described in “Element Removal and
Replacement” (page 22).
E.) Insert a pump hose into the water
heater’s chamber and pump all of
the water out.
F.) Reinstall the hea ng element as
described in “Element Removal and