9-4.Diagnosis Flow Chart For Each Error Code; 9-4-1.Hydro Unit Failure Detection - Toshiba HWS-803XWHM3-E Service Manual

9-4. Diagnosis flow chart for each error code
9-4-1. Hydro unit failure detection
[A01] Error Pump flow determination
Operation restarts
Pump rotates
Perform
air vent
Yes
Excess air noise
comes from inside
Chattering noise comes
from flow switch
Pump stops 2-3
minutes after its rotation
TC sensor characteristic
Flow switch is normal
Water heat exchanger control board
is defective, replace it
[A01] occurs
No (No pump sound)
Yes
the pump
No
No
No
Yes
started
No
Flow shortage
No
is correct
Yes
No
Yes
Flow switch is
connected to board
Yes
Built-in pump is
connected to board
Yes
Flow switch is normal
Yes
(Identify causes, and resolve)
Dirt clogging inside
water circuit
(strainer)
12 M or longer water
pipe to a branch,
or 5 or less branches
91
No
Connect flow switch
connector to board
No
Connect pump
connector to board
No
Replace flow switch
Replace pump
Replace TC sensor
Remove waste
Fit buffer tank and the
second pump
Attach or replace
flow switch