9
• Inspect the return-air duct connection(s) at the furnace to
ensure it is physically sound, sealed to the furnace casing,
and terminates outside the space containing the furnace.
• Inspect electrical wiring, connections, and components for
loose connections.
• Perform an operational checkout to determine whether
your furnace is working properly and if it requires
adjustments.
• Inspect all condensate drain tubes and condensate trap
assembly for leaks. The condensate removal system should
be cleaned annually by a qualified service agency. Refer
to the Service and Maintenance Instructions for further
information.
• Examine the physical support of the furnace. Support
should be sound with no cracks, sagging, gaps, etc. around
the base.
• Check furnace for any obvious signs of deterioration.
BEFORE YOU REQUEST A SERVICE CALL
If your furnace is not operating or not performing properly,
you may save the expense of a service call by checking a few
things yourself before calling for service.
FOR INSUFFICIENT AIRFLOW:
• Check for dirty air filter(s).
• Check for blocked return-air or supply-air grilles through-
out your home. Ensure they are open and unobstructed.
If problem still exists, call your dealer for service.
IF FURNACE FAILS TO OPERATE:
Follow this checklist step by step, advancing to the next step
only if furnace fails to start.
• Check thermostat for proper temperature. Is thermostat
set above room temperature?
• Is thermostat switch on HEAT?
• Check fuses and circuit breakers. Is electrical supply on?
• Is manual shut-off valve in gas supply pipe in open posi-
tion? (Follow start-up procedures if you open gas valve.)
NOTE:
Turn off electrical supply before continuing with
checklist.
• Is control knob on gas valve in ON position? (Follow start-
up procedures if you must reset knob to ON.)
• Check manual reset flame rollout switch located on the
burner box. (See Fig. 2 or 3.) If furnace has experienced high
temperature conditions, this switch will shut off the furnace.
Reset it by pushing the button on the switch. If it trips again,
shut down the furnace and call for service. See section “Shut-
ting Down Your Furnace” in this manual.
• Check for obstructions around the vent termination.
If the furnace still fails to operate, call your service
representative.
For your convenience, record the furnace product and serial
numbers on page 2. Should you ever require service, you
will have ready access to the information needed by your
service representative.
This furnace has an LED operation and fault code display
to aid the installer, service technician, or homeowner
while installing or servicing the unit. The LED code can
be seen by removing the access door and viewing the
LED(s) through the view port in the blower access panel.
NOTE:
Removing the blower access panel or turning off the
115-v electrical power supply will terminate LED diagnostic
code display.
To decipher the meaning of the LED code, and suggested
action, the following cross-reference can be used.
MODEL 58MCA and 58MXA DIAGNOSTIC CHART
(See Fig. 3.)
NOTES:
1. Light on continuously means control has power and working properly.
2. The status codes are a 2 digit number. The first digit is determined by the number of short flashes of the light and the second digit is determined by number of
long flashes of the light.
FAULT
CODE
FAULT CODE DESCRIPTION
CHECKLIST
13 or 33
Limit Switch Lockout
M
Check for dirty air filter.
M
Check for blocked return-air or supply-air grilles.
14 or 34
Ignition Lockout or
Ignition Proving Fault
M
Check to be sure manual shut-off valve in gas supply pipe is in the open position. (Follow start-up proce-
dure if you open gas line.)
NOTE:
Turn off the electrical supply and remove access doors before continuing with this
checklist.
M
Check to be sure control knob on gas valve is in ON position. (Follow start-up procedures if you must reset
dial to ON.)
24
Furnace Fuse Open
M
Check for blown fuse and possible short in 24-v wiring.
31
Pressure Switch Not Closed
M
Check to make sure that all PVC pipes leading into the combustion-air intake and vent/exhaust are free
from any cracks and sags. Also check the combustion-air intake and vent/exhaust pipes on the outside of
your home for blockage.
12, 21, 22,
or 23
Any Other
Fault Code
M
Call dealer for service.
No Fault
Code
Signaled
Furnace Fails to Operate and No
Fault is Signaled
M
Check thermostat for proper temperature setting.
M
Check for blown fuses and circuit breakers.
M
Check to be sure blower access panel is properly in place.
