Page 22 of 25
507640-05
Issue 2245
Control System Diagnostics
LED Status
Flashing Rate
Fault Description
Slow Flash
One flash per
second
Normal operation:
No call for heat
Fast Flash
Two flashes per
second
Normal operation:
Call for heat
2 Flash
Two flashes in
1 second with
1-second pause
System lockout:
Failed to detect or
sustain flame
3 Flash
Three flashes in
1.5 seconds with
1-second pause
Pressure switch senses
incorrect pressure or gas
valve coil is open.
4 Flash
Four flashes in
2 seconds with
1-second pause
High limit or rollout
switch open
5 Flash
Five flashes in
2.5 seconds with
1-second pause
Flame sensed and gas
valve not energized
6 Flash
6 Flashes in 3
seconds with
1-second pause
Rollout switch open
Steady
--
Internal failure:
Micro-controller failure;
self-check
Table 5. Fault Codes
Secure Owner’s Approval
When the system is functioning properly, secure the owner’s
approval. Show the owner the location of all disconnect
switches and the thermostat. Instruct the owner on how
to start and stop the unit and how to adjust temperature
settings within the limitations of the system.