TROUBLESHOOTING
If the under-ceiling fan coil unit fails to start or operate
properly, sometimes the problem is minor and can be handled
without a service call. Refer to Table 9 for some common
problems, causes, and typical solutions. See Fig. 25 and 26
for additional system troubleshooting details. If the problem
cannot be corrected, contact your local Carrier representa-
tive for further assistance.
Table 9 — Troubleshooting
PROBLEM
CAUSE
TYPICAL SOLUTION
System does
not start.
Blown fuse or circuit breaker tripped at building
power entry.
Replace fuse or reset circuit breaker.*
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.
Compressor three-minute timer is running.
Wait for 3 minutes.
Temperature is above or below the selected temperature.
Select new temperature using the thermostat.
System does not
cool properly.
Air filter(s) in indoor unit is dirty or needs to be replaced.
Clean or replace air filter(s).
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 replaced.
Clean or replace air filter(s).
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 on
indoor coil.†
Low outdoor-air temperature.
Run system in fan-only mode until frost is gone.
Air filter(s) in indoor unit is dirty or needs
to be replaced.
Clean or replace air filter(s).
Insufficient
airflow
Air filter(s) in indoor unit is dirty or needs
to be replaced.
Clean or replace air filter(s).
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 Carrier rep-
resentative for assistance.
†When outdoor temperature is approximately 55 F or below, indoor
coil frosting may occur when system is operated in cooling or maxi-
mum dehumidification mode.
REAR VIEW
NOTE: See Fig. 3 for dimensions.
Fig. 24 — Field Installation of Ventilation-Air Accessory
17
Summary of Contents for 40QA
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