935SA: Installation, Start-up, Operating and Service Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
51
A200236
Fig. 63 – Service Label Information
Component Self-Test
To initiate the component test sequence, shut OFF the room thermostat
or disconnect the “R” thermostat lead. Briefly short the TEST/TWIN
terminal to the “C” terminal. Status LED will flash most recent code 4
times and then turn ON the inducer motor.
The inducer motor will run for the entire component test. The hot surface
igniter, blower motor fan speed, blower motor-heat speed, and blower
motor-cool speed will be turned ON for 10-15 seconds each. Gas Valve
and Humidifier will not be turned on.
Troubleshooting
Refer to the service booklet. (see
)
Care and Maintenance
For continuing high performance and to minimize possible furnace
failure, periodic maintenance
must be performed on this furnace.
Consult your local dealer and Owner’s Manual ab
out proper frequency
of maintenance and the availability of a maintenance contract.
The minimum maintenance on this furnace is as follows:
1. Check and clean air filter each month or more frequently if
required. Replace if torn.
2. Check blower motor and wheel for cleanliness each heating and
cooling season. Clean as necessary.
3. Check electrical connections for tightness and controls for proper
operation each heating season. Service as necessary.
4. Inspect the vent pipe/vent system before each heating season for
water leakage, sagging pipes or broken fittings. Have vent
pipes/vent system serviced by a qualified service agency.
SECTION 1
LED CODES - STATUS
SERVICE
COMPONENT TEST
LED CODES - STATUS
LED ACTIVITY
If status code recall is needed, briefly (2-3 seconds)
remove then reconnect one main limit wire to display
stored status code. After status code recall is completed
component test will occur.
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. Check for poor or no ground (GND).
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 BY THE NUMBER OF LONG FLASHES.
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. If BTS is also open,
the inducer will operate as well.
13 LIMIT CIRCUIT LOCKOUT - Lockout occurs if a limit is open.
Control will auto-reset after three hours. Check for:
-Loose blower wheel - Restricted vent - Proper vent sizing
- Dirty filter or restricted duct system - Defective switch or connections
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 untill fault is cleared.
Check for: - Leaky gas valve - Stuck-open gas valve.
23 PRESSURE > 0.15” 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.
26 BURNER THERMAL SWITCH (BTS) open - if switch is
open during call for heat (W), then a permanent lockout
will occur. Cycle power to reset lockout.
Check for: -Blocked burner inlet -Blocked burner mesh
-Poor inducer flow -Excess wind
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 (115 VAC)
- Frozen or blocked drain - 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
42 INDUCER MOTOR FAULT the RPM pulses are not detected from the inducer
motor within 20 seconds after a heat request, the inducer is outside of its valid
range of operation, or the inducer RPM signal was lost for 5 seconds during
operation, Inducer exceeds model specific RPM limit.
Check for: - Proper vent sizing – Restricted combustion air supply
– Failed inducer motor – Improper or loose motor wiring or bad connection.
– Frozen or blocked drain.
45 CONTROL CIRCUITARY LOCKOUT Auto-reset after one hour
lockout due to: - Gas valve relay stuck open - Flame sense circuit failure
- Software check error
Reset power to clear lockout. Replace control if status code repeats
To initiate the component test sequence, shut OFF the room thermostat or disconnect the “R” thermostat lead.
Briefly short the TEST/TWIN terminal to the “C” terminal. Status LED will flash most recent code 4 times and then
turn ON the inducer motor. The inducer motor will run for the entire component test. The hot surface igniter, blower
motor fan speed, blower motor-heat speed, and blower motor-cool speed will be turned ON for 10-15 seconds
each. Gas Valve and Humidifier will not be turned on.
11 Indicates the blower motor tested OK. Visual check of inducer motor and hot surface igniter required.
25 SETUP ERROR - Reference code 25 above.
42 INDUCER MOTOR FAULT - Indicates inducer motor failed test. Check inducer, wiring, furnace control and tubing
for poor connections. See code 42 above.
CODE DESCRIPTION
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
Never store flammable or combustible materials on, near, or in contact
with the furnace, such as:
1. Spray or aerosol cans, rags, brooms, dust mops, vacuum cleaners,
or other cleaning tools.
2. Soap powders, bleaches, waxes or other cleaning compounds,
plastic or plastic containers, gasoline, kerosene, cigarette lighter
fluid, dry cleaning fluids, or other volatile fluids.
3. Paint thinners and other painting compounds, paper bags, or other
paper products. Exposure to these materials could lead to
corrosion of the heat exchangers.
WARNING
!
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Turn off the gas and electrical supplies to the furnace and install lockout
tag before performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace.
WARNING
!
CARBON MONOXIDE POISONING AND FIRE
HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
Never operate furnace without a filter or filtration device installed.
Never operate a furnace with filter or filtration device access doors
removed.
CAUTION
!
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and wear
appropriate protective clothing, safety glasses and gloves when
handling parts, and servicing furnaces.
