White Rodgers 50A65-843 User Manual

7

When system lockout occurs, the gas valve is de-energized, the
circulator blower is energized at heat speed, and, if flame is
sensed, the inducer blower is energized. The diagnostic indica-
tor light will flash or glow continuously to indicate system status.
(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 de-energized, interrupting the call for
heat at the thermostat will not reset the control).

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.

The 50A65-843 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 field-repairable.

If the sensed failure is in the system (external to the control), the
LED will flash in the following flash-pause sequences to indicate
failure status (each flash will last approximately 0.25 seconds,
and each pause will last approximately 2 seconds).

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

8 flashes, then pause

Check ignitor

Continuous flashing

Flame has been sensed when

(no pause)

no flame should be present (no
call for heat)

The LED will also flash once at power-up.