Fujitsu Airstage J-II Service Manual page 154

Check Point 5 : Check Opening and Closing Operation of Valve
When Valve is closed,
it has a temp. difference between Inlet and Outlet.
CLOSE
Example : Hot GUS
Pipe (In)
Check Point 6 : Check Strainer
Strainer normally does not have temperature difference between inlet and outlet as shown in (1), but if there is a difference
as shown in (2), there is a possibility of inside clogged. In this case, replace Strainer.
(1)
Pipe (In)
If it is open, it has no temp. difference between Inlet and Outlet.
OPEN
Example : Hot GUS
Pipe (Out)
(2)
Pipe (Out)
04-92
Pipe (In)
Pipe (In)
Pipe (Out)
Pipe (Out)