T-D2-IN / T-D2-OS Service Manual
Ver. 1.00
31
CONFIDENTIAL
10-15. Computer board
Unit Part #
#701
Takagi Part #
EK439
Checkpoint
N/A
Function
Controls the functions of most of the parts in the water heater.
Failure events
Malfunctioning computer
Effects on the water
heater if the computer
board fails
-A component(s) may not operate within the water heater. In most cases
of computer board failure, the whole the water heater does not operate at
all.
-Error codes will display.
Error codes when the
computer board fails
701
721
741
761
Diagnostic
Visual inspection: connection/breakage of wires and/or burn marks on the
computer board.
Color/Number of wires
N/A
6
-
1
/
2
"
(
1
6
5
.0
5
m
m
)
5 - 3 / 8 " ( 1 3 8 m m )
1 - 3 / 8 " ( 3 5 m m )
The computer board
differs from one in
the T-K3-SP/OS.
