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58SU0A (Series 2 & 3): Troubleshooting Guide
SERVICE/STATUS CODE INSTRUCTIONS
If status code recall is needed disconnect the "R" thermostat lead, reset power, and put setup switch "SW1-1" in the ON position. To clear the status
code history put setup switch "SW1-1" in the ON position and jumper thermostat terminals "R", "W/W1", and "Y/Y2" simultaneously until status
code #11 is flashed.
LED CODES
STATUS
CONTINUOUS OFF
Check for 115VAC at L1 and L2, and 24VAC at SEC-1 and SEC-2
CONTINUOUS ON
Control has 24VAC power.
RAPID FLASHING
Line voltage (115VAC) polarity reversed.
Each of the following status codes is a two digit number with the first digit determined by the number of short flashes and the second digit is
the number of long flashes.
LED ACTIVITY (CFH = Call for Heat)
11
NO PREVIOUS CODE - Stored status codes are erased automatically after 72 hours or as specified above.
12 BLOWER ON AFTER POWER UP (115VAC or 24VAC) - Blower runs for 90 seconds, if unit is powered up during a call
for heat (R-W closed) or (R-W opens) during a blower on-delay period.
13 LIMIT CIRCUIT LOCKOUT - Lockout occurs if a limit, draft safeguard, burner thermal switch or blocked vent switch
(if used) is open. Control will auto-reset after three hours. Check for:
- Loose blower wheel
- Restricted vent
- Proper vent sizing
- Excess wind
- Dirty filter or restricted duct system
- Defective switch or connections
- Inadequate combustion air supply (Burner thermal switch open)
14 IGNITION LOCKOUT - Control will auto-reset after three hours. Refer to status code #34.
21 GAS HEATING LOCKOUT - Control will NOT auto-reset. Check for:
- Mis-wired gas valve
- Defective control (valve relay)
- 24VAC sensed at gas valve when should not be present
22 ABNORMAL FLAME - PROVING SIGNAL - Flame is provided while gas valve is de-energized, inducer will run until fault is
cleared. Check for:
- Leaky gas valve
- Stuck-open gas valve
23 PRESSURE > 0.15-in. w.c. AT START-UP. Check for:
- Obstruction in pressure tubing or Transducer vent holes
- Defective Transducer
-Transducer wiring
24 SECONDARY VOLTAGE FUSE IS OPEN. Check for:
- Short circuit in secondary voltage (24VAC) wiring
25 INVALID MODEL SELECTION OR SETUP ERROR - Indicated either the model plug is missing or incorrect. If code
flashes 4 times
on power-up control is defaulting to model selection stored in memory
31 PRESSURE TRANSDUCER INPUT DOES NOT SENSE TARGET PRESSURE OR PRESSURE IS OUT OF RANGE.
Check for:
- Excessive wind- Proper vent sizing
- Restricted vent
- Defective inducer motor
- Inadequate combustion air supply
- Defective pressure transducer
- Low inlet gas pressure (if LGPS used)
- Low inducer voltage (115VAC)
- Disconnected or obstructed pressure tubing
34 IGNITION PROVING FAILURE - Control will try ignition four times before lockout #14 occurs. If flame signal lost during
blower on-delay period, blower will come on for the selected blower off-delay. Check for:
- Oxide buildup on flame sensor (clean with fine steel wool)
- Proper flame sense microamps (.5 microamps D.C. Min., 4.0 - 6.0 nominal)
- Manual valve shut-off- Low inlet gas pressure
- Control ground continuity
- Gas valve defective or turned off
- Flame sensor must not be grounded or touching casing
- Inadequate flame carryover or rough ignition
- Green/Yellow wire MUST be connected to furnace sheet metal
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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