NO FAULT IN RECENT HISTORY DISPLAY- Indicates no faults have occurred within the last five cycles. To read recent fault history, put setup switch "SW-1" in the "ON" position. To clear recent fault history, put setup switch "SW-1" in the "ON" position and jumper thermostat terminals "R", "W/Wl" and "Y/Y2" simultaneously until an "11" is flashed.
BLOWER CALIBRATION LOCKOUT- Indicates RPM calculated for low heat was less than 250 RPM or greater than 1300 RPM on two successive attempts. Auto reset after three hours. Reset power
LIMIT SWITCH LOCKOUT- Indicates the occurrence of 10 successive limit trips during high heat or three successive limit trips during low heat. Auto reset after three hours. Check for ^Improper or misaligned limit and/or limit shield. ^Improper high or low heat qas input adjustment. *Stuck high heat solenoid in gas valve.
IGNITION LOCKOUT- Control will auto-reset after three hours.
INVALID MODEL SELECTION- Indicates model plug is missing or incorrect.
SETUP ERROR- Indicates setup switch "SW-1" or "SW-6" is positioned improperly. The following combinations will cause the fault:
^Thermostat call with "SW-1" "ON", or Thermostat call with "SW-6" "ON", or "SW-1" and "SW-6" both "ON" together.
INVALID BLOWER AIRFLOW SELECTION- Indicates improper "A/C" or "CF" switch setting. The 042 and 14 units can deliver 1-1/2 to 3-1/2 tons A/C and 600 to 1400 CFM for continuous fan. The 060 and 20 unit can deliver 2 to 5 tons A/C and 800 to 2000 CFM for continuous fan. If code is flashing, unit will default tp closest allowable airflow.
SECONDARY VOLTAGE FUSE IS OPEN Check for: - Short circuit in secondary voltage (24VAC) wiring.
PRESSURE SWITCH DID NOT CLOSE OR REOPENED - If open longer than five minutes, inducer shuts off for 15 minutes before retry. Check for: - Excessive wind
- Proper vent sizing - Defective inducer motor - Low inducer voltage (115VAC) - Defective pressure switch - Inadequate combustion air supply - Restricted vent
- Disconnected or obstructed pressure tubing - Low inlet gas pressure (if LGPS used) If it opens during blower on- delay period, blower will come on for the selected blower off-delay
LIMIT CIRCUIT FAULT - Indicates a limit, or flame rollout is open. Blower will run for 4 minutes or until open switch remakes whichever is longer.
If open longer than 3 minutes, code changes to lockout #13. If open less than 3 minutes status code #33 continues to flash until blower shuts of Flame rollout switch requires manual reset. Check for: - Restricted vent - Proper vent sizing - Loose blower wheel - Excessive wind - Dirty filter or restricted duct system.
- Defective blower motor or capacitor. - Defective switch or connections. - Inadequate combustion air supply (Flame Roll-out Switch open).
IGNITION PROVING FAILURE - Control will try three more times before lockout #14 occurs. If flame signal lost during blower on-delay period, blower will come on for the selected blower off-delay. Check for: - Control ground continuity - Flame sensor must not be grounded - Oxide buildup on flame sensor (clean with fine steel wool)
- Proper flame sense microamps (.5 microamps D.C. min., 4.0 - 6.0 nominal). - Gas valve defective or gas valve turned off - Manual valve shut-off - Defective Hot Surface Ignitor - Low inlet gas pressure
- Inadequate flame carryover or rough ignition - Green/Yellow wire MUST be connected to furnace sheet metal
BLOWER OUTSIDE VALID SPEED RANGE- Indicates the blower is not operating at the calculated RPM. If this fault occurs in conjunction with fault #44 check wiring to motor otherwise
Bryant 340MAV Furnace Error Codes
FAULT CODE DESCRIPTION
13 or 33
Limit Switch Lockout
- Check for dirty air filter.
- Check for blocked return-air or supply-air grilles.
14 or 34
Ignition Lockout or Ignition Proving Fault
- Check to be sure manual shutoff valve in gas supply pipe is in the open position. (Follow start-up procedure if you open gas line.)
- Check to be sure control switch or knob on gas valve is in ON position. (Follow start-up pro- cedures if you must reset switch or knob to ON position.)
- Check for disconnected ground wire.
Furnace Fuse Open
- Check for blown fuse and possible short in 24-v wiring.
Pressure Switch Not Closed
- 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
- Call dealer for service.
No Fault Code Signaled
Furnace Fails to Operate and No Fault is Signaled
- Check thermostat for proper temperature setting.
- Check for blown fuses and circuit breakers.
- Check to be sure blower access panel is properly in place.
Bryant 355M-40-4 Furnace Error Codes
RED LED1 ON
Furnace is operating in emergency heat.
RED LED2 ON
The microprocessor has malfunctioned. To reset: Put setup switch "SW-1" in the "ON" position nad jumper thermostat terminals "R", "W/Wl" and "Y/Y2" simultaneously with the door switch pushed in and power to the unit "ON". Disconnect jumper and place setup switch in the "OFF" position. If LED2 reappears, replace main control board.