SYSTEM LOCKOUT AND
DIAGNOSTIC FEATURES
SYSTEM LOCKOUT FEATURES
When system lockout occurs, the gas valve is
(System lockout will never override the precautionary fea- tures.)
To reset the control after system lockout, do one of the following:
1.Interrupt the call for heat or cool at the thermostat for at least one second but less than 20 seconds (if flame is sensed with the gas valve
2.Interrupt the 24 VAC power at the control for at least one second. You may also need to reset the flame rollout sensor switch.
3.After one hour in lockout, the control will automatically reset itself.
DIAGNOSTIC FEATURES
The 50A55 control continuously monitors its own operation and the operation of the system. If a failure occurs, the LED will indicate a failure code as shown below. If the failure is internal to the control, the light will stay on continuously. In this case, the entire control should be replaced, as the control is not
If the sensed failure is in the system (external to the control), the LED will flash in the following
1 flash, then pause | System lockout |
2 flashes, then pause | Pressure switch stuck closed |
3 flashes, then pause | Pressure switch stuck open |
4 flashes, then pause | Open limit switch |
5 flashes, then pause | Open rollout switch |
6 flashes, then pause | 115 Volt AC power reversed/Im- |
| proper ground |
7 flashes, then pause | Low flame sense signal |
Continuous flashing | Flame sensed with gas valve |
(no pause) | off |
The LED will also flash once at
7
