TO OBTAIN INFORMATION ON PARTS: Consult your installing dealer or classified section of your local telephone directory under the
“Heating Equipment’’ or “Air Conditioning Contractors & Systems’’ headings for dealer listing by brand name.
Have available the Model No., Series Letter & Serial No. of your equipment to insure correct replacement part.
Carrier Corporation Syracuse, New York 13221
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
.
Copyright 1994 Carrier Corporation
Form: OM58-67
Replaces: OM58-61
Printed in the U.S.A.
6-94
PC 101
Catalog No. 535-882
MODEL 58MVP DIAGNOSTIC CHART
(See Fig. 4.)
NOTES:
1. Red light 1 on continuously means furnace is operating in emergency heat.
2. Red light 2 on continuously means the microprocessor board has malfunctioned.
3. Yellow light on continuously means furnace is operating in high heat.
4. Green light on continuously means furnace is operating in low heat.
5. The status codes are a 2 digit number. The first digit is determined by the number of flashes of the yellow light and the second digit is determined by number of
flashes of the green light.
FAULT
CODE
FAULT CODE DESCRIPTION
CHECKLIST
12
Blower Calibration Lockout
M
Check for dirty air filter.
M
Check for blocked return-air or supply-air grilles.
M
Turn electrical supply off, then back on. Set the thermostat switch to call for heat.
13 or 33
Limit Switch Lockout
14 or 34
Ignition Lockout or
Ignition Proving Fault
M
Check to be sure manual shut-off valve in gas supply pipe is in open position. (Follow start-up procedure 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).
M
Check for disconnected ground wire.
24
Furnace Fuse Open
M
Check for blown fuse and possible short in 24-v wiring.
31, 32, or 43
Pressure Switch Fault
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.
42
Inducer Outside Valid
Speed Range
44
Blower Calibration Fault
M
Check for dirty air filter(s).
M
Check for blocked return- or supply-air grilles.
NOTE: In zoned applications, fault 44 may flash during operation when a single zone is calling for heat.
When other zones call for heat, or the unit cycles, the fault should clear itself. Call for service if fault 12
develops.
21, 22, 23,
or 41
Any Other Fault Code or Either of the
Red Lights On Continuously
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
Be sure thermostat switch is on HEAT.
M
Check for blown fuses and circuit breakers.
M
Check to be sure blower access panel is properly in place.