Goodman GPC SERIES - User Manual

Questions and Answers

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Larry McguireAug 19, 2025
Why is my Goodman Air Conditioner not cooling enough?
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  Christopher JohnsonAug 20, 2025
  If your Goodman Air Conditioner is not cooling sufficiently, several factors could be responsible. First, verify that the unit is properly sized for the space it's cooling by recalculating the load. Next, check the airflow, ensuring it's approximately 400 CFM per ton. An incorrect refrigerant charge could also be the cause; make sure to charge the unit per the procedure attached to the unit service panel. Finally, ensure the voltage at the compressor terminals is within 10% of the nameplate volts when the unit is operating.
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Jeffrey McneilAug 22, 2025
Why are the registers sweating in my Goodman GPC system?
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  Cassandra VelazquezAug 22, 2025
  If your Goodman Air Conditioner has registers that are sweating, it is likely due to low airflow. To resolve this, increase the speed of the blower or reduce any restrictions, such as replacing the air filters.
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Christopher ShawAug 26, 2025
What to do if the condenser fan runs, but the compressor doesn't in my Goodman Air Conditioner?
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  hector67Aug 26, 2025
  If your Goodman Air Conditioner's condenser fan is running but the compressor isn't, there are several potential causes. First, check for loose connections and ensure there is proper voltage at the compressor. Tighten any loose connections. If the connections are secure, the compressor might be stuck, have a grounded or open winding, or an open internal overload. Wait at least 2 hours for the overload to reset. If it remains open, the compressor may need replacement. Additionally, check the voltage at the compressor terminals, ensuring it's within 10% of the nameplate volts when the unit is operating. Finally, inspect the capacitor for any signs of weakness, being open, or shorted and replace it if it's defective.
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gcarrilloAug 28, 2025
Why is the evaporator coil freezing or frosting in my Goodman GPC?
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  Katherine HarveyAug 28, 2025
  If your Goodman Air Conditioner's evaporator coil is freezing or frosting, there are a few possible reasons. The first thing to check is the airflow. It should be approximately 400 CFM per ton. Also, inspect the air filters to see if they are dirty and make sure all the duct outlets are open. Another potential cause is a low refrigerant charge, so ensure the unit is properly charged. Lastly, operating the unit in cooling mode below 65°F outdoor temperature can cause freezing. In this case, install or check the low ambient control, which should be open below 65°F.
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Gabriel YoungAug 30, 2025
Why does my Goodman Air Conditioner compressor short cycle?
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  Mr. John Powers PhDAug 31, 2025
  If your Goodman Air Conditioner's compressor is short cycling, it could be due to a defective overload protector. If this is the case, replace it and check for the correct voltage. Another potential cause is the unit cycling on low-pressure control, so check the refrigerant charge and/or airflow.
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Rachel SuarezSep 2, 2025
What causes high head pressure with high or normal suction in a Goodman GPC Air Conditioner?
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  Nicole PerrySep 2, 2025
  If your Goodman Air Conditioner has high head pressure and high or normal suction, it could be due to a dirty condenser coil. To resolve this, clean the coil. Another possible cause is that the system is overcharged, so correct the system charge. Finally, the condenser fan may not be running, in which case it should be repaired or replaced.
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John BarnesSep 5, 2025
What causes low suction and an iced evaporator coil in my Goodman GPC Air Conditioner?
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  Monique RossSep 5, 2025
  If your Goodman Air Conditioner has low suction and a cool compressor with an iced evaporator coil, the problem is likely low indoor airflow. To fix this, increase the speed of the blower or reduce any restrictions, such as replacing the air filters.
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harold07Sep 8, 2025
What causes high head pressure and low suction in a Goodman Air Conditioner?
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  Frank RodriguezSep 8, 2025
  If your Goodman Air Conditioner has high head pressure and low suction, it may be due to a restriction in the liquid line or flowrator. Remove the restriction or replace the flowrator with the proper size.
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avilakeithSep 12, 2025
What causes low head pressure and high suction in a Goodman GPC?
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  Carlos FoxSep 12, 2025
  If your Goodman Air Conditioner has low head pressure and high suction, it could be due to an incorrect flowrator. If that's the case, replace it with the correct one. Another possible cause is defective compressor valves, which would require replacing the compressor. Finally, the flowrator may not be seating properly. Check for debris under the flowrator or a deformed flowrator. Remove any debris or replace the flowrator.
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Lisa BonillaSep 13, 2025
What causes high suction pressure in my Goodman GPC?
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  shafferloganSep 13, 2025
  If your Goodman Air Conditioner has high suction pressure, it could be due to an excessive load. Recheck the load calculation. It may also be caused by a defective compressor, which would need to be replaced. Another possibility is that the reversing valve is not seating properly, in which case it should be replaced.

Summary

Installation & Operating Instructions for Self-Contained Package Air Conditioners and Heat Pumps GPC;GPH Series

Important Safety Instructions

Recognize Safety Symbols, Words, and Labels

Understand hazard symbols, words, and labels for safety compliance and risk reduction.

Installation

Pre-Installation Checkpoints

Essential pre-installation considerations including structural integrity, clearances, power, and duct connections.

Ducting

Connecting the Return and Supply Flexible Duct

Guidelines for attaching flexible ductwork using converter kits and proper sealing.

Plenum Application

Requirements for plenum construction and insulation for exposed ductwork.

Filters

Filters are not included; installer must supply and install with adequate face area.

Piping

Condensate Drain

Proper installation of a condensate drain trap with a positive liquid seal is required.

Wiring

High Voltage Wiring

Instructions for connecting high voltage power supply to unit terminals.

Low Voltage Wiring

Wiring 24V control wires from thermostat to unit control box for AC and Heat Pumps.

Operation

Start-Up Procedure and Checklist

Step-by-step guide for initial unit startup and operational checks.

Heat Pump Start-Up Procedure

Specific procedures for starting up heat pump in cooling and heating modes.

Final System Checks

Final checks on air distribution, ductwork, unit rattles, and owner instruction.

Components

Contactor

Control activated by thermostat to supply power to compressor and outdoor fan motor.

Crankcase Heater

Heater activated when power is supplied to prevent liquid migration and compressor damage.

Condenser Motor

Activated by contactor during heating/cooling, except during defrost and emergency heat.

Explanation and Guidance (Heat Pump)

Heat Pump Refrigerant Circuit

Schematic illustrating refrigerant flow for cooling and heating cycles.

Defrost Control

Suggested Field Testing;Trouble Shooting

Air Flow Measurement and Adjustment

Procedures for measuring and adjusting airflow using blower curves and ESP.

Adjusting Speed Tap for Indoor Blower Motor

PSC Motor

Adjusting CFM by changing speed taps on EBTDR 'com' connection.

X-13 Motor

Setting blower speed for cooling, heat pump, and electric heat using 24V leads.

Checking Charge

Superheat Can Be Determined As Follows

Method for determining superheat using suction pressure and temperature readings.

Electric Heat Installation & Adjustment

Troubleshooting Chart

Goodman GPC SERIES Specifications

General

Refrigerant	R-410A
Stages	Single
SEER Rating	Up to 16 SEER
Cooling Capacity (BTU/h)	18, 000 - 60, 000 BTU/h
Compressor Type	Single-Stage
Warranty	10-year limited parts warranty