Lennox LICH4012021T431E-1, Service Manual

Page: 145 / 164

Troubleshooting
Electrical Control System
143
2.4.4.13. J1 Malfunction
Malfunction conditions When the outdoor pipe temperature is more than 65°C, the unit stops. It
starts again only when the outdoor pipe temperature is less than 52°C.
Possible causes
●
Faulty condenser temperature sensor
●
Dirty heat exchanger
●
System leakage or blockages
J1 displayed
J1 displayed
High temperature protection of
condenser
High temperature protection of
condenser
Is the condenser
temperature is Higher than
65°C?
Is the condenser
temperature is Higher than
65°C?
Yes
Is the resistance of
condenser temp. sensor
normal according
to
Appendix 1
Is the resistance of
condenser temp. sensor
normal according to
Appendix 1
Replace the temperature sensor
Replace the temperature sensor
No
No
Is the outdoor ambient
temperature higher than
50
℃ ?
Is the outdoor ambient
temperature higher than
50
℃ ?
No
Stop the unit
Stop the unit Yes
Is the outdoor unit ventilation
functioning properly?
Is the outdoor unit ventilation
functioning properly?
Yes
Ensure that the outdoor unit
ventilate is functioning properly
Ensure that the outdoor unit
ventilate is functioning properly
Is the heat exchanger dirty?
Is the heat exchanger dirty?
No
Clean the heat exchanger
Clean the heat exchanger
Yes
Check whether the refrigerant
system is functioning normally
Check whether the refrigerant
system is functioning normally
Replace outdoor main
board. Has the problem
been resolved?
Replace outdoor main
board. Has the problem
been resolved?
No
If the level of refrigerant is not
sufficient, does the system work after
refrigerant is added?
If the level of refrigerant is not
sufficient, does the system work after
refrigerant is added?
No
Is the outdoor fan running
properly?
Is the outdoor fan running
properly?
Refer to the solution to the
malfunction of fan speed being out of
control . Find the cause and resolve the
problem.
Refer to the solution to the
malfunction of fan speed being out of
control . Find the cause and resolve the
problem.
No
Yes
No
Correct the connection
Correct the connection No
Yes
Is the connection between
temperature sensor and
PCB in working order?
Is the connection between
temperature sensor and
PCB in working order?
Yes