Carrier 40QA024-060 Troubleshooting, Problem, Cause, Typical Solution, System Does Not Start

Table 7 — Troubleshooting

PROBLEM	CAUSE	TYPICAL SOLUTION
System Does Not Start.	Blown fuse or circuit breaker tripped at building	Replace fuse or reset circuit breaker.*
	power entry.
	Indoor and/or outdoor unit disconnect switch is off.	Turn on disconnect switch(es).
	Thermostat is set to night mode.	Cancel mode using Day/Night button on thermostat.
	Power failure.	Restore power.
	Unit is in off mode.	Press Mode button on thermostat until thermostat
		displays the desired unit mode.
	Three-minute time delay is running.	Wait for 3 minutes.
	Temperature is above or below the selected	Select new temperature using the thermostat.
	temperature.
System Does Not Cool Properly.	Air filter(s) in indoor unit is dirty or needs to be	Clean or replace air filter(s).
	replaced.
	Temperature is set too high or too low.	Reset temperature to desired comfort setting using
		the thermostat.
	Outdoor unit outdoor coil restricted.	Remove obstruction.
	Fan speed is set too low.	Adjust fan speed to high or auto. using the Fan
		button on the thermostat.
System Does not Heat Properly.	Air filter(s) in indoor unit is dirty or needs to be	Clean or replace air filter(s).
	replaced.
	Temperature is set too high or too low.	Reset temperature to desired comfort setting using
		the thermostat.
	Outdoor unit outdoor coil restricted.	Remove obstruction.
	Fan speed is set too low.	Adjust fan speed to high or auto. using the Fan
		button on the thermostat.
	Outdoor unit outdoor coil is frosted up.	Check manual defrost timer setting and adjust as
		necessary.
Ice or frost has Formed	Low outdoor-air temperature.	Run system in fan-only mode until frost is gone.
on Indoor Coil.†
	Air filter(s) in indoor unit is dirty or needs to be	Clean or replace air filter(s).
	replaced.
Insufficient Airflow.	Air filter(s) in indoor unit is dirty or needs to be	Clean or replace air filter(s).
	replaced.
	Fan coil unit coil is blocked.	Clean air discharge louvers.

*If fuse blows or circuit breaker trips again after first start attempt, DO NOT attempt to start system again. Contact your local dealer for assistance.

†When outdoor temperature is approximately 55 F or below, indoor coil frosting may occur when system is operated in cooling or maximum dehumidification mode. Units are not intended to operate below 55 F without appropriate accessories.

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