Справочник Пользователя для White Rodgers 50M56-743

White-Rodgers is a business 
of Emerson Electric Co.

The Emerson logo is a  
trademark and service mark 
of Emerson Electric Co.

1

External lockout 
(exceeded retries)

Failure to sense flame is often caused by carbon deposits on the flame 
sensor, a disconnected or shorted flame sensor lead or a poorly grounded 
furnace. Carbon deposits can be cleaned with emery cloth. Verify sensor is 
not contacting the burner and is located in a good position to sense flame. 
Ignitor must be positioned to light the gas immediately when the valve 
opens. If the ignitor has been replaced, verify hot spot position has not 
changed.
Check sensor lead for shorting and verify furnace is grounded properly. 
Verify gas supply to valve, gas valve in "On" position and appliance 
lighting properly. Verify flame reaches flame sensor during ignition 
attempts and gas pressures are correct. 

2

Pressure switch stuck 
closed

Pressure switch stuck closed. Check switch function, verify inducer is 
turning off. Refer to wiring diagram, terminals PSI / PSO.

3

Pressure switch stuck 
open

Check pressure switch function and tubing. Verify inducer is turning on 
and pulling sufficient vacuum to engage switch. Refer to wiring diagram, 
terminals PSI / PSO.

4

Open high temperature 
limit switch

Verify continuity through limit switch circuit. Refer to wiring diagram 
terminals, HLI / HLO. 

5

Flame sensed with gas 
valve 
de-energized

Verify the gas valve is operating and shutting down properly. Flame in 
burner assembly should extinguish promptly at the end of the cycle. Check 
orifices and gas pressure.

6

Open rollout switch 

Verify continuity through rollout switch circuit. Refer to wiring diagram 
terminals, RO IN / RO OUT. 

7

Low flame sense current

Low flame sense current is often caused by carbon deposits on the flame 
sensor, a poorly grounded furnace or a mis-aligned flame sense probe. 
Carbon deposits can be cleaned with emery cloth. 
Check or improve furnace and module ground. Verify sensor is located in 
or very near flame as specified by the appliance manufacturer. Refer to 
wiring diagram FS terminal and GND.  

8

Ignitor relay fault

This flash code does not indicate a broken, disconnected or shorted 
ignitor. It indicates the ignitor relay contacts on the ignition module are not 
functioning properly. Replace the ignition module. 

Rapid Flash

Reversed polarity

Verify the control and furnace are properly grounded. Check and reverse 
polarity (primary or secondary) if incorrect. 

Continuous On

Normal operation

No fault

Off 

Control failure

Verify power to the control, replace control if power is at the control and no 
lit Red LED