High-Pressure Protection - Lennox LI036CI-180P432 Service Manual

(10) High-pressure Protection

High-pressure protection
Use pressure gauge to
measure if the pressure is
Check if the operation mode of
indoor unit is set properly?
Check if the gas valve and
liquid valve are fully open ?
Check if the front panel of
outdoor unit is covered tightly?
Check if the air inlet and outlet of
the indoor and outdoor
exchanger is smooth ?
Check if the indoor and
outdoor fans operate normally?
Check if the indoor swing
louver is fully open ?
Check if the capacity output of
outdoor unit is equal to the
capacity demand of indoor units ?
Check if the indoor / outdoor
filters or radiating fins are dirty or
Clean the fins
70
no
really high?
yes
no
yes
no
yes
no
yes
no
yes
no
yes
no
yes
no
yes
no
blocked ?
no
yes
Measure if the pressure switch
is normal
no
Set the correct operation
mode
Fully open the valve
Cover up the front panel
properly
Remove the obstructions
Measure the fan motor and
signal input
Measure the swing motor and
signal input
Refer to the dial -up of indoor
and outdoor unit
The system pipe is blocked
Replace the mainboard of
outdoor unit
Replace the pressure switch
Replace the blocked parts or
pipe
Installation and Maintenance
Service Manual