Operating instructions

Cancels: OM05-26 OM05-30
© 2000 Bryant Heating & Cooling Systems, 7310 W. Morris St., Indpls., IN 46231
12 Printed in U.S.A. Catalog No. 5335-510 10-00
MODEL 355MAV 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 fault code is 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 Check for dirty air filter.
Check for blocked return-air or supply-air grilles.
Turn electrical supply off, then back on. Set the thermostat to call for heat.
13 or 33 Limit Switch Lockout
14 or 34
Ignition Lockout or
Ignition Proving Fault
Check to be sure manual shutoff 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.
Check to be sure control switch or knob on gas valve is in ON position. (Follow start-up
procedures if you must reset switch or knob to ON position).
Check for disconnected ground wire.
24 Furnace Fuse Open Check for blown fuse and possible short in 24-v wiring.
31, 32, or 43 Pressure Switch Fault 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
Check for dirty air filter(s).
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
Call dealer for service.
No Fault
Code
Signaled
Furnace Fails to Operate and No
Fault is Signaled
Check thermostat for proper temperature setting.
Be sure thermostat is set to HEAT.
Check for blown fuses and circuit breakers.
Check to be sure blower access panel is properly in place.