Maintenance
Tronic 3000T – 6 720 801 072 (2022/07)
12
▶ Turn the heater upside down over a sink to drain the water
out of it.
-or-
it can also be emptied by:
▶ Siphon through the inlet side hose.
▶ Keep a hot water faucet open while siphoning.
-or-
If the heater has been installed with rigid piping:
▶ Siphon the water out through any (lower) service valve on
the (inlet side).
▶ Keep a hot water faucet open while siphoning the water out.
5.3
Inspecting the anode rod
The purpose of the anode rod (
Fig. 12, [N]) is to protect the
tank against corrosion. It is critical that the anode rod be
inspected once a year to determine whether it requires
replacement (and it must be replaced at least once every two
years). To access the anode rod, the heating element must be
removed (see Section 5.4 Removing the heating element).
Upon inspection, the anode rod surface should appear smooth.
If the rod surface appears pitted, bumpy, rusty, or if the rod is
missing completely, then it must be replaced before the water
heater can be put back into operation.
To access the anode rod:
▶ Remove the heating element (see Section 5.4 Removing
the heating element).
Original anode rod sizes
•
ES2.5, ES4: length 5⅛", diameter ⅝"
•
ES8:length 6½", diameter ¾"
Certain installations may require more frequent replacement of
the anode rod:
•
recirculation applications;
•
poor water quality;
•
galvanic/electrolytic corrosion
•
high flow applications
In the event of poor water quality, Bosch recommends
consulting a local water treatment professional for water
treatment options. Always ensure the water heater is grounded.
Models ES2.5 and ES4 must be connected only to a properly
grounded outlet. Damage resulting from poor water quality or
failure to replace the anode rod is not covered under the
manufacturer’s warranty. For additional questions, please call
Bosch Technical Service.
5.4
Removing the heating element
▶ Turn off power supply and drain the heater (see previous
section).
▶ Remove the front cover plate, disconnect terminals X, Y and
T.
▶ Unscrew the 4 heating element retaining nuts F.
▶ Remove thermostat temperature sensor from well [B]
located on the element assembly.
▶ Remove the element G.
Fig. 10
Fig. 11
6720801072-09.1V
G
Z
F
X
Y
T
A
E
H
B
6720801072-10.1V
G
Summary of Contents for ES 2.5
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