Bryant 355MAV Troubleshooting Manual page 18

Fault Code 22
SETUP ERROR—THIS FAULT INDICATES THAT SETUP SWITCHES SW-1 OR SW-6 ARE ON WHEN THEY SHOULD BE OFF.
THE FOLLOWING COMBINATIONS WILL CAUSE THE FAULT:
• Thermostat call with SW-1 ON.
• Thermostat call with SW-6 ON.
• SW-1 and SW-6 both ON together.
STEP
1. Turn power off and remove blower access panel.
Make sure thermostat is NOT calling for heating or cooling. Disconnect all thermostat terminal leads
2.
to make sure.
3. Is setup switch SW-1 in ON position?
4. Put setup switch SW-1 in OFF position.
Go to page number indicated in Index for CLEANUP AND START-UP
5.
INSTRUCTIONS.
6. Is setup switch SW-6 in ON position?
7. Put setup switch SW-6 in OFF position.
8. Replace furnace control board.
Fault Code 23
INVALID BLOWER AIRFLOW SELECTION—THIS FAULT INDICATES IMPROPER A/C OR CF SWITCH SETTING. THE -14
UNITS CAN DELIVER SUFFICIENT AIRFLOW FOR 1-1/2 TO 3-1/2 TONS A/C AND 600 TO 1400 CFM FOR CONTINUOUS FAN.
THE -20 UNIT CAN DELIVER SUFFICIENT AIRFLOW FOR 2 TO 5 TONS A/C AND 800 TO 2000 CFM FOR CONTINUOUS FAN.
IF FAULT CODE IS FLASHING, UNIT STILL OPERATES, BUT IT DEFAULTS TO CLOSEST ALLOWABLE AIRFLOW.
NOTE: Boards with date codes of 9506 or later will flash fault code and set continuous fan airflow to same airflow as A/C if continuous fan is
adjusted to a higher airflow than A/C setting.
STEP
1. Turn power off and remove blower access panel.
2. Are air conditioning select switches A/C set properly? (See Table 2.)
3. Set air conditioning select switches A/C for proper tonnage as required by condensing unit.
Go to page number indicated in Index for CLEANUP AND START-UP
4.
INSTRUCTIONS.
5. Are continuous fan select switches CF set properly? (See Table 3.)
Set continuous fan select switches CF for desired airflow. This setting should normally be set to DE-
6. FAULT position unless a 2-speed AC/HP is part of system. Use Table 4 for reference on 2-speed
AC/HP airflow requirements.
Are continuous fan select switches CF set to a higher airflow than air conditioning select switches
7.
A/C? (See Tables 2 and 3.)
8. Is furnace a 100 size?
The problem is in the A/C or CF selection circuit. The maximum cooling or continuous fan airflow for
9.
this unit will be delivered.
Jiggle A/C and CF switches back and forth. If fault code continues to flash, replace furnace control
10.
board.
The problem is in the A/C or CF selection circuit. The minimum cooling or continuous fan airflow for
11.
this unit will be delivered.
Jiggle A/C and CF switches back and forth. If fault code continues to flash, replace furnace control
12.
board.
ACTION
ACTION
—18—
YES NO GO TO
— — 2
— — 3
4 6 —
— — 5
— — INDEX
7 8 —
— — 5
— — 5
YES NO GO TO
— — 2
5 3 —
— — 4
— — INDEX
7 6 —
— — 4
6 8 —
11 9 —
— — 10
— — 4
— — 12
— — 4