Takagi T-K3 Service Manual

T-K3 Service Manual
Ver. 1.05
32
CONFI DENTIAL
11. Fault Analysis & Specifications
Re mar ks :
1 Proper range of values of voltage & resistance shown below.
2 Please refer to the wiring diagram for checkpoint positions.
3 Remove power to T-K3 when checking for continuity, disconnections, resistance value
Checkpoint
1 Check the power supply
①
Check the power supply from the GFI to the PCB
(Refer to section 12-2)
② Check the power supply line to the T-K3
2 Fault of GFI
Normal: AC100V between
(
white-black
)
A
Normal: AC100V between (brown-brown) A1
3 Fault of transformer
①
Disconnection / breakage of wires
Normal: AC120V between
(
white-black
)
A2
Normal: AC100V between (brown-brown) A1
4 Blown fuse at PCB (3A) A2
5 Fault of PCB
①
No voltage at remote control terminal
Normal: 11VDC - 25VDC between
(
white-black
)
6 Disconnection/short-circuit/grounding of remote wires
Normal: 11VDC - 25VDC between
(
white-black
)
7 Fault of PCB of remote control
①
1
1
2 Check whether the gas supply pressure is enough.
3 Check whether the temperature setting is too low.
・
The water is too hot 1 Check whether the tem
p
erature settin
g
is too hi
g
h.
1 Make sure the unit gets a 120V 60Hz power supply.
2
3 Check that the filter on the cold water inlet is clean.
4
5 Check that the filter on the cold water inlet is clean.
6 Check whether or not the unit is frozen.
7 Check if there is enough gas in the tank. (for propane units)
F
Check for normal volta
g
e at terminal
・
It takes long time to
get hot water at the
fixtures
The time it takes to deliver hot water from the T-K3 to
your fixtures depend on the length of piping between
them. The longer the distance and/or the bigger the
pipes, the longer it will take to get hot water.
Check whether the hot water fixture is suff iciently open
to draw at least 0.5 GPM through the water heater.
Nature of Fault Diagnosis
・
No display on
temperature remote
controller, even when
remote is turned on.
・
The water is not hot
enough
Check cross plumbing between cold water lines and hot
water lines.
・
The hot water is not
available when a
fixture is opened
If the remote controller is used, check whether the
power button is turned on.

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