Takagi T-K3 Service Manual

T-K3 Service Manual
Ver. 1.05
18
CONFI DENTIAL
10-6. AFR rod
T-K3 Part # #716 Takagi Part # EKK0E Checkpoint I
Functions
Failure event
Effects on the T-K3
if the AFR rod fails
Error codes when
the AFR rod fails.
101 991 391
D iagnostic
The AFR rod is assembled with the flame rod.
(during operation) 1
μ
A or more
-Checks flame conditions during combustion.
- When AFR r od d etects un expected flam e conditions, the T- K3's co mputer mak es
adjustments in the fan motor speed to compensate.
1. Visual inspection: connection/braking of wires, soot on it.
2. Check voltages: proper range of values are shown below.
Color/Number of
wires
1. Unable to detect flames when flames actually do occur
2. Detecting a false flam e when no fl am es actua lly occur
1. Th e T- K3 stops op er ating. The "111" and/or "121 " er ror code(s) wi ll display
2. The T-K3 will not initiate the ignition process. The "721" error code will display
3. Th e fan motor speed cannot be modulated pro pe rly unde r abno rma l flam e
conditions, which can result in excessive CO emission.
Yellow (8) - Green (18)
(during operation) 40KHz~60KHz
Yellow (8) - AFR rod:
between the AFR r od and the
computer board
1-3/8" (35mm)
5/8" (15mm)
7/8" (24mm)
3-1/2" (88.6mm)
2-1/4" (58.6mm)
AFR Rod
Flame rod
Leads to computer board
Detecting elements (AFR and flame rods)

Takagi T-K3 Specifications

General

Type	Tankless
Installation Type	Indoor
Maximum BTU Input	199, 000 BTU/h
Gas Connection Size	3/4"
Vent Size	3"
Hot Water Flow Rate (at 35°C rise)	6.6 GPM
Maximum Input	199, 000 BTU/h