Bryant air troubleshooting

The tables below will give you a chance to learn about some common problems associated with the air conditioning systems, and the easiest ways of troubleshooting them. Depending on your qualifications, experience, desire, and the type of malfunction you may either call for service or try to fix the appliance on your own, saving money and time.

Bryant 187B I air troubleshooting

Standby no call for unit operationNoneOn solid, no flashNormal operation
Low-stage Cool/Heat OperationNone1, pause
High-stage Cool/Heat OperationNone2, pause
System Communications Failure16Communication with user interface lost. Check wiring to User Interface, indoor and outdoor units
Invalid Model Plug25Control does not detect a model plug or detects an invalid model plug. Unit will not operate without correct model plug.
High Pressure Switch Open31High-pressure switch trip. Check refrigerant charge, outdoor fan operation and coils for airflow restrictions.
Low Pressure Switch Open32Low pressure switch trip. Check refrigerant charge and indoor air flow
Control Fault45Outdoor unit control board has failed. Control board needs to be replaced.
Brown Out (230 v)46Line voltage < 187v for at least 4 seconds. Compressor and fan operation not allowed until voltage>190v. Verify line voltage.
No 230v at Unit47There is no 230v at the contactor when indoor unit is powered and cooling/ heating demand exists. Verify the disconnect is closed and 230v wiring is connected to the unit.
Outdoor Air Temp Sensor Fault53Outdoor air sensor not reading or out of range. Ohm out sensor and check wiring.
Outdoor Coil Sensor Fault55Coil sensor not reading or out of range. Ohm out sensor and check wiring.
Thermistors out of range56Improper relationship between coil sensor and outdoor air sensor. Ohm out sensors and check wiring.
Low stage Thermal Cutout71Compressor operation detected then disappears while low-stage demand exists. Possible causes are internal compressor overload trip or start relay and capacitor held in circuit too long (if installed)
High stage Thermal Cutout72
Contactor Shorted73Compressor voltage sensed when no demand for compressor operation exists. Contactor may be stuck closed or there is a wiring error.
No 230V at Compressor74Compressor voltage not sensed when compressor should be starting. Contactor may be stuck open or there is a wiring error.
Low-stage Thermal Lockout81Thermal cutout occurs in three consecutive low/ high-stage cycles, low-stage locked out for 4 hours or until 24v power recycled.
High-stage Thermal Lockout82
Low Pressure Lockout83Low pressure switch trip has occurred during 3 consecutive cycles. Unit operation locked out for 4 hours or until 24v power recycled.
High Pressure Lockout84

Bryant EVOLUTION 577D-A air troubleshooting

Power failureCall power company
Fuse blown or circuit breaker trippedReplace fuse or reset circuit breaker
Defective contactor, transformer, control relay, or high- pressure, loss-of-charge or low-pressure switchReplace component
Insufficient line voltageDetermine cause and correct
Compressor and outdoor fan will not startIncorrect or faulty wiringCheck wiring diagram and rewire correctly
Ul setting too lowfloo highReset Ul setting
Units have a 5-minute time delayDO NOT bypass this compressor time delay-wait for 5 minutes until time-delay relay is de-energized
Compressor will not start but condenser fan runsFaulty wiring or circuit
Loose connections in compressor
Check wiring and repair or replace
Compressor motor burned out, seized, or internal overload openDetermine cause Replace compressor
Defective run capacitor, overload, or PTC (positive temperature coefficient) thermistorDetermine cause and replace
Low input voltage (20 percent low)Determine cause and correct
Compressor cycles (other than normally satisfying) cooling/heating callsRefrigerant overcharge or underchargeRecover refrigerant, evacuate system, and re- charge to capacities shown on rating plate
Defective compressorReplace and determine cause
Insufficient line voltageDetermine cause and correct
Blocked outdoor coil
Defective run/start capacitor, overload or start relay
Faulty outdoor fan motor or capacitorReplace
Restriction in refrigerant systemLocate restriction and remove
Compressor operates continuouslyDirty air filterReplace filter
Unit undersized for loadDecrease load or increase unit size
Ul temperature set too lowReset Ul setting
Low refrigerant chargeLocate leak, repair, and recharge
Air in systemRecover refrigerant, evacuate system, and re- charge
Outdoor coil dirty or restrictedClean coil or remove restriction
Excessive head pressureDirty air filterReplace filter
Dirty indoor or outdoor coilClean coil
Refrigerant overchargedRecover excess refrigerant
Air in systemRecover refrigerant, evacuate system, and re- charge
Indoor or outdoor air restricted or air short-cyclingDetermine cause and correct
Head pressure too lowLow refrigerant chargeCheck for leaks, repair and recharge
Restriction in liquid tubeRemove restriction
Excessive suction pressureHigh heat loadCheck for source and eliminate
Reversing valve hung up or leaking internallyReplace valve
Refrigerant overchargedRecover excess refrigerant
Suction pressure too lowDirty air filterReplace filter
Low refrigerant chargeCheck for leaks, repair and recharge
Metering device or low side restrictedRemove source of restriction
Insufficient coil airflowCheck filter-replace if necessary
Temperature too low in conditioned areaReset Ul setting
Outdoor ambient below 55°F (13°C)Verify low-ambient cooling enabled in Ul
Filter drier restrictedReplace
IFM does not runBlower wheel not secured to shaftProperly tighten blower wheel to shaft
Insufficient voltage at motorDetermine cause and correct
Power connectors not properly sealedConnectors should snap easily; do not force
IFM operation is intermittentWater dripping into motorVerify proper drip loops in connector wires
Connectors not firmly sealedGently pull wires individually to be sure they are crimped into the housing
Burners will not igniteWater in gas lineDrain. Install drip leg.
No power to unitCheck power supply fuses, wiring or circuit breaker.
No 24-v power supply to control circuitCheck transformer. NOTE: Some transformers have internal over- current protection that requires a cool-down peri- od to reset.
Mis-wired or loose connectionsCheck all wiring and wire nut connections
Misaligned spark electrodesCheck flame ignition and sense electrode positioning. Adjust as necessary.
No gas at main burners1. Check gas line for air. Purge as necessary. NOTE: After purging gas line of air, wait at least 5 minutes for any gas to dissipate before attempt- ing to light unit.
2. Check gas valve.
Inducer pressure switch not closing1. Check pressure switch wires, connections, and tubing. Repair or replace if necessary.
Inadequate heatingDirty air filterClean or replace filter as necessary
Gas input to unit too towCheck gas pressure at manifold match with that on unit nameplate
Unit undersized for applicationReplace with proper unit or add additional unit
Restricted airflowClean or replace filter. Remove any restriction.
Limit switch cycles main burnersCheck rotation of blower, temperature rise of unit. Adjust as necessary.
Poor flame characteristicsIncomplete combustion results in: Aldehyde odors, carbon monoxide, sooting flame, floating flame1. Tighten all screws around burner compartment
2. Cracked heat exchanger. Replace.
3. Unit over-fired. Reduce input (change orifices or adjust gas line or manifold pressure).
4. Check burner alignment.
5. Inspect heat exchanger for blockage. Clean as necessary.

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