A.O. Smith T-H2-DV User Manual

T-H2-DV/T-H2-OS Service Manual
Ver. 1.01
36
CONFIDENTIAL
10-17. Freeze protection heaters
Unit Part #
#405
#415
#426
#453
#454
Takagi Part #
EX002
EKK2P
EKJ47
EX13P
EX13R
Checkpoint B1
Function
Prevents the heat exchanger, water valves, and water pipes within the water
heater from freezing. The heaters are but one of the freeze protection
devices in the water heater.
Failure events
Open circuit failure: Ceramic heaters do not receive the voltage needed to
heat up.
Effects on the water
heater if heater fails
Ceramic heaters do not activate, allowing water contained in the heat
exchanger to freeze up, possibly causing the heat exchanger to burst.
Error codes when
heaters
fails
N/A
Diagnostic
1. Visual inspection: connection/breakage of wires and the condition of the
heaters.
2. Check: whether those are in the normal range as shown in the following
table.
Color/Number of wires Black - Black
AC90〜110V (during freeze protection operation)
3 array heater (#454 / EX13R)
Heater
For the outlet pipe (#415 / EKK2P)
Flat Heater (#453 / EX13P)
Heater (#405 / EX002)
Pipe heater
(#426 / EKJ47)
For heat exchanger

A.O. Smith T-H2-DV Specifications

General

Brand	A.O. Smith
Model	T-H2-DV
Category	Water Heater
Language	English