Service manual
i
i
4.
Heater does not work. (compressor and fan operate)
MSH-OSDW
-
IU;I1
t
Heating selected
?
Is blow out air temp.
140' F for MSH-OSDW
151'F for MSH-12/15DN or below
?
Is
set
temp, minus
room
temp.
larger than
5°F
?
Check voltage to heater.
Yes
Is
there 1 15V AC
between
heater
connector
-
CJ]
7
I
t
Is there continuity to
Replace
fuse
(FS)
fuse
(FS)
?
of heater
assembly
I
Yes
Is there continuity to
heater (H)
?
Nml
I
Replace heager (H)
I
/
Check voltaae to heater contactor 88H
\
I
i
for MSH-O~DW-~1 or 88H1. 88H2,
for MSH-12/15DN-Ul. Replace Heater contactor
Is there 12V DC betweeen heater contactor
88H or 88H
1,
88H2.
I
Check resistance of heater control
thermistor RT13.
No
0
See
the thermistor resistance on page
40,
43.
I
Replace Heater control
thermistor RT13.
Yes
I
Replace Electronic control P.C. board.
1