5407934-UIM-C-1119
50
Johnson Controls Ducted Systems
TABLE 16:
Modulating Furnace
Fault (Displayed Text) Description
Category
FURNACE: FLAME
W/OUT POWER
Flame is present with no power being
supplied to gas valve. This can be
caused by a gas valve that is slow to
close or that leaks gas through to the
burners.
Critical
FURNACE: HIGH LIMIT
OPEN
High limit switch or 24 V fuse is open.
This can be caused by restricted airflow
or an open fuse.
Critical
FURNACE: ROLLOUT OR
AUX OPEN
Rollout or auxiliary switch open. Reset
the rollout switch if possible. Check the
limit switch in the air blower housing.
Critical
FURNACE GAS VALVE
FAILURE
Current failure on modulating gas valve Critical
FURNACE: SUPPLY PWR
REVERSED
Reversed line polarity or improper
grounding. Check the polarity of incom-
ing power and grounding. Check the
transformer.
Critical
FURNACE: GAS VALVE
CIRCUIT SHORT
Gas valve circuit shorted. Check the
gas valve wiring. If correct, replace the
gas valve.
Critical
FURNACE: BLOWER
FAILURE
Main blower failure
Critical
FURNACE: NO MODEL
PLUG
ID plug is not present or not connected
properly. Check for loose plug or loose
wires in plug.
Critical
FURNACE: JUMPER
ERROR
Jumper error
Critical
FURNACE: PRESSURE
SWITCH OPEN
Stuck open pressure switch indicates
that the pressure switch is open when it
should be closed
Critical
FURNACE: IGNITION
FAILED
Lockout due to no ignition. Check gas
supply, ignitor, gas valve, and flame
sensor.
Critical
FURNACE: MULTI FLAME
DROPOUTS
Lockout due to too many flame recy-
cles. This can be caused by a faulty
gas valve, low gas pressure, or a dirty
flame sensor.
Critical