"J7" Four-way Valve Air
Backflo w Protection
Replace th e 4-way valve
Yes
Whether th e voltage at the output of the
main boar d is normal? (If th e voltage at the output does n ot
meet requirements, the output voltage of the fo ur-way valve
is 220V when it is e nergized)
Whether the four-way valve
coil is connected to the main
board p roperly?
Yes
Confirm that the four-way valve is abnormal
No
Conne ct them prope rly and
reliably
No
Replace the main control
board
Whet her t he diffe rence b etwe en
th e h igh pressure an d the low p ressure of t he
un it d urin g ope r ation is greate r tha n 0.1 MPa? At the same
time t ouch th e f ou r-way valve by hand to see whether it is hot or cold. In
coo lin g mo de, E pipe an d S pip e a re o f low t empe rature an d low p r essure,
while D p ipe an d C p ipe ar e of h igh temp eratu re a nd high pre ssure; in
he at in g m o de, D pip e a nd E p ipe are of high te mp eratu r e a nd
high p ressur e, while S pip e a nd C pip e a re
of low te mp er at ure a nd low p ressure.
Yes
Yes