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6 Simple Steps to Troubleshooting a Compressor

KB Delta is an expert in understanding compressor valves and compressor valve parts. Rely on them to provide the steps to troubleshooting a compressor.
Troubleshooting a Compressor With Our Repair Kit | KB Delta

The core of any refrigeration system is the compressor, and most of the troubleshooting that needs to be done when a system doesn’t work correctly boils down to this one piece of equipment.

Whether you’re an expert certified in HVAC systems or a DIY die-hard looking to repair a compressor system, the essential steps are the same.


Troubleshooting a Compressor: Is It Always The Same Process?

Although the steps are the same, the scale of the operation and the possible consequences of overlooking a step in the process may differ between compressors.

When you apply a methodical approach to troubleshooting a compressor, it helps eliminate opportunities to overlook the cause of the problem by ensuring that every aspect of the compressor’s operation is reviewed for issues.

When troubleshooting a compressor of a refrigeration system, there are really only 6 simple steps to follow.


1. Measure the Suction and Discharge Pressures

Since the job of the compressor is to move supercooled refrigerant from the evaporator to the condenser, checking for pressure problems is essential when diagnosing issues with the system’s operation.

Using standard refrigeration gauges is the easiest method, but you can also get a measurement using a digital multimeter and pressure module if you don’t have access to standard refrigeration gauges at the time of troubleshooting.

Keep in mind that the system will likely be under high pressure when setting and removing your gauges, and use safe refrigerant handling protocols to keep the system from losing refrigerant.


2. Check the Discharge Line Temperature

In addition to pressure, temperature measurements help you get a good idea of what is going on inside an air compressor.

Use the pipe clamp accessory on your DMM to get a measurement. 275 to 300 degrees Fahrenheit is the high side of the temperature range, above that, the performance of the compressor will suffer because the temperature will be high enough to destroy lubricant properties.

Since high temperatures can be caused by low refrigerant pressure, insufficient charge, or the intrusion of noncondensible gas in the system (among other things), this data point can be compared to other information like your pressure readings to rule out symptoms of these major sources of compressor performance trouble.


3. Record Temperatures in the Refrigerated Space

Another vital data point in your troubleshooting diagnosis is the temperature of the space needing refrigeration in AC or refrigerator.

It’s important to understand the nature of the cooling system in use and the target temperatures the compressor should be attaining when recording this number.

These factors will assist you in determining the extent of the compressor’s performance flaws, which will also aid in the confirmation or elimination of hypotheses about the problem. If you happen to reach out to air conditioner repair services, the first thing they might do while examining the issue is to carry out this step. The most important step is to identify the problem. Once you’ve identified the problem, you may need to purchase replacement compressor valve parts.

Your air conditioner could be malfunctioning as a result of improper maintenance, for which you may require the assistance of Air conditioning services in Painesville, OH. With a faulty HVAC compressor, an air conditioning unit can still appear to operate. The AC unit is outfitted with a pair of fans that can continue to run even if the compressor fails. As a result, calling a technician to inspect the issues may be a viable option.


4. Perform a Compressor Valve Test

Use the following method when testing the hermetic and semi-hermetic pressures of compressors. Using the pressure module on your DMM, do the following:

  • Connect the module at the suction line service port
  • Close the compressor on the low side of the system by front seating the suction service valve
  • Let it run for at least two minutes, but not more than three
  • Turn off the compressor and take the reading

The compressor should pull around 15 inches of Hg. If the pressure displays around 10 or less, that means the discharge valves are likely leaking and need replacements. If it does not pull below 15 inches of Hg, then the suction valves will likely need to be replaced. On the other hand, if you do not notice any primary fault in the compressor valve, there are chances that your compressor is in pristine condition. In that case, you may need to look for other areas of concern that are inhibiting the cooling process of the air conditioner. As an example, if your air ducts are clogged with dirt, dust, and cobwebs, hire a Minneapolis air duct cleaning (or a similar firm based on your location) for the cleaning of air ducts. Similarly, you can scan other areas of the air conditioning system for problems if your compressor is not faulty.


Contact Us Today For Compressor Valve Repair | KB Delta


5. Checking for Compressor Electrical Motor Faults

Checking for failures in the compressor’s electric motor helps, especially if the system is accessible enough to allow for compressor repair without full compressor replacement.

Use a clamp meter to check both AC voltage and AC current. Make sure you check line voltage at the load center with the compressor off, as well as voltage at the motor terminals with the compressor running.

Line voltage that is too high will lead to premature failure, and too low will result in more performance issues.

This should be within 10 percent of the motor rating. Make sure you also check the running current, and voltage and compare it to the manufacturer’s safe maximum amps.

However, if you are unsure how to check the line voltage, you can contact professionals from a company that provides Weston electrical services. This is due to the fact that if you are unaware of such issues, they can have disastrous consequences. You do not need to jeopardize your life to resolve any of the issues that can best be handled by trained and experienced professionals.


6. Refrigerant System Problems

Sometimes mechanical problems are the core issue when compressors fail to function properly, but more often there are refrigerant system problems contributing to the issue in ways that cause the mechanical failure.

By replacing a compressor without checking for and fixing these issues, system failure will reoccur with the same basic symptoms.

Rule out these issues when replacing or troubleshooting a compressor.

  • Poor piping practices prevent oil from properly returning to the compressor while running
  • High discharge temperatures create acids that can damage the system
  • Insufficient air flow to either the condenser or evaporator coil
  • Low suction pressures
  • Liquid refrigerant flooding back

Sometimes you can fix these issues by replacing the compressor itself, like when a mechanical problem in the compressor causes low suction pressure. When the root of the problems is system design, though, the compressor replacement will necessitate changing some elements of the system’s function to get better long-term results.



The process of troubleshooting a compressor will reveal which aspects of the compressor’s operation are compromised. This is key to understanding how to fix those problems.

Be thorough, and document each measurement, because you often need the results of multiple steps to draw conclusions about the source of issues with the system’s performance.

And feel free to contact KB Delta for all your compressor valve needs and information about compressor valve parts.


6 Simple Steps to Troubleshooting a Compressor - KB Delta

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