Modulating Furnace - Johnson Controls Hx 3 S1-THXU430W Installation Manual

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