Daitsu DS-9KIDR - 4-Way Value Reversing Abnormal

Air Conditioner Service Manual
58
3.2.19 F8---4-Way Value Reversing abnormal
On heating mode, if IDU Coil temperature tested lower than Room temperature 5℃ or even more after compressor
works for 8min, unit will show F8 code.
Display F8
Is there 220V
voltage on the 4-
way valve?
Replace ODU PCB
Multimeter test the
valve coil resistance,
does it open or short
circuit?
Replace 4-way valve coil
End
the 4-way valve
wiring connection
correct?
Re-connect
F8 disappear?
F8 disappear?
Yes
No
Yes
Yes
Yes
Yes
No
No
No
No