York DHP30NWB21SDCP30NWB21SDHP36NWB21SDCP36NWB21S Service Manual page 47

Display Method of Indoor Unit
Indicator Display (during
blinking, ON 0.5s and OFF
Dual-8
Malfunction
NO.
0.5s)
Code
Name
Operation
Display
Indicator
Normal
53 communica-
tion
54 Defrosting
Malfunction
of zero-cross
U8
55
detection
circuit
Display Method of Outdoor Unit
Indicator has 3 kinds of display
status and during blinking, ON
0.5s and OFF 0.5s
Cool Heating Yellow
Indicator Indicator Indicator Indicator
OFF 3S
and blink
once
(during
OFF 1S
blinking,
and blink
ON 10s
twice
and OFF
0.5s)
A/C status
Red Green
Indicator
OFF 0.5S
and blink
once
Defrosting will occur in
heating mode.
Compressor will operate
while indoor fan will stop
operation.
The complete unit stops
Possible Causes
It's the normal state
1.Power supply is abnormal;
2.Detection circuit of indoor
control mainboard is abnormal.
40