how do i troubleshoot my hvac compressor

Troubleshooting AC Compressor Problems in 5 Steps

Full Answer

How do I troubleshoot my HVAC?

• Refrigerant Leaks. Excessive water and/refrigerant around the HVAC unit may indicate an issue with the drainage pipes or a damaged pump.
• Tripping Circuit Breaker. ...
• Constant Running. ...
• Frozen Coils. ...
• Noise. ...
• Importance of Air Filter Replacement. ...
• Avoid Costly Repairs. ...
• Sansone is Florida’s #1 HVAC Services Provider. ...

How do you troubleshoot a defective compressor?

Troubleshooting The Compressor And Diagnosing Mechanical Problems

• Discharge Line Temperature. Pressure and temperature are fundamental tests that you can perform to determine what is happening inside the compressor.
• Recording Temperatures. ...
• Compressor Valve Performance Test. ...
• Compressor Electrical Motor Faults. ...
• Refrigeration System Problems. ...

How to change HVAC compressor?

• Shut the AC breakers off in the breaker panel.
• Remove the power disconnect block on the outside of the home. ...
• Remove the access panel on the condensing unit and use a screwdriver to short the Herm and Common terminals as well as the Fan and Common terminals on the capacitor.
• Remove the fan shroud and pull it out of the way.

More items...

How do you change a compressor in a HVAC system?

• Replace just the compressor.
• Replace the entire outside unit or the condensing unit.
• Replace the condensing unit along with the evaporator coil.
• Buy a new AC.

How to check if AC is blowing cold air?

What to do if your AC isn't running?

Why is my refrigerator low on freon?

Why is my HVAC system not working?

Why does my AC unit turn off?

When did RSI start training HVAC technicians?

Do HVAC technicians need to be certified?

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How do you know if you have a bad HVAC compressor?

Bad AC Compressor Symptoms System overheats. Lukewarm air coming from the vent. Low levels of refrigerant. Moisture leaks from parts of the HVAC system.

What is the first step in troubleshooting an air compressor failure?

Before starting, simply check the power button and switch. Breakers should also be checked if necessary. Aside from lack of electrical power, air compressors can also fail if it lacks sufficient air pressure in relation to the cut-in pressure.

How do you troubleshoot a defective compressor HVAC?

6 Simple Steps to Troubleshooting a Compressor. ... Measure the Suction and Discharge Pressures. ... Check the Discharge Line Temperature. ... Record Temperatures in the Refrigerated Space. ... Perform a Compressor Valve Test. ... Checking for Compressor Electrical Motor Faults. ... Refrigerant System Problems.

How do I reset my HVAC compressor?

How to Reset an Air ConditionerPower down your AC. Start at your circuit breaker panel and flip the breaker that powers your AC. ... Find the button. Most air conditioning units are equipped with a reset button. ... Hold down the reset button for 3 to 5 seconds and then release.Restore power to your AC.

What is the most common cause of air compressor failure?

Oil Issues Compressors require oil to keep parts lubricated and avoid overheating, but oil isn't supposed to get into the air lines. If it does, it can cause seals to swell, crack, and eventually fail. Piston rings and intake filters should be replaced periodically to prevent this problem.

Where is reset button on compressor?

Look for it first around on the exterior of your machine, especially along the bottom edge near the ground. An AC's reset button is typically red and visible, so it should be easy to spot. If you don't see a reset button on the outside, it could be located inside the unit behind the service panel.

How do you tell if a compressor is burnt out?

When an air conditioning compressor has "burned out" by shorting of internal components - it will fail to start at all. This failure is detected by disconnecting all power and wiring from the unit and measuring resistance (ohms) between the motor start/common and run/common terminals.

What happens when HVAC compressor goes bad?

When your ac compressor fails, less air will come out from the vents, the air coming out could be warm, and the system may continually run without actually cooling your home. This is because refrigerant isn't pumped through the system, and it can result in a higher power bill.

What causes a compressor to stop working?

Top Reasons Your AC Compressor Stopped Working Dirty condenser coils. Blocked suction lines. Low refrigerant charge. Incorrect suction line size.

How long does it take for a compressor to reset?

After you've turned the system back on, it will take a bit of time for the air conditioner's internal circuitry to reset. It usually takes about 30 minutes, so sit tight until then. 5. Switch on the AC system at the thermostat.

How long does it take an AC compressor to reset?

After waiting for 1 minute, the AC unit will reset on its own. Go to your thermostat and carefully turn the device back on. Be sure to set the device to your desired temperature and wait for the unit to cool the air to confirm it's working well.

Why is my air compressor not getting pressure?

The most common reason behind a reciprocating compressor's inability to reach sufficient pressure is a defective reed valve — which can exhaust air out from the air inlet on single stage models or, through the intercooler safety valve in the case of a defective reed valve on a two-stage piston compressor instead of ...

What is the first step in troubleshooting an air conditioning system?

The first step for air conditioner troubleshooting is a look at your thermostat settings. Your thermostat is your air conditioner's control system – it tells the air conditioner when to cycle on and off to maintain adequate temperatures inside the house.

When starting air compressor What is the first thing you should check?

Checks before Starting the Air Compressor Check the lube oil in the crankcase sump by means of dipstick or sight glass. All the valves of compressor discharge must be in normally open condition. If any manual valve is present in un-loader line, it must always be kept open.

What to do when compressor is not working?

Troubleshooting AC Compressor ProblemsCheck for tripped breakers. Find the breaker for the air conditioner in your service panel. ... Test the thermostat. Make sure the thermostat is set correctly and has fresh batteries. ... Listen for buzzing. ... Listen for clicking.

What are the starting procedures of the air compressor?

Open the compressor discharge valve & charging valve of air bottle. Open cooling water system valves. Turn the compressor flywheel by hand (one turn). Start the motor, after draining the moisture shut the drain valve.

Commonly Reported HVAC Problems - Hannabery

Listed below, are commonly reported HVAC (Heating, Ventilation, and Air Conditioning) problems. By clicking on a problem, it will take you to a page discussing the problem along with possible causes and remedies.

HVAC Troubleshooting Problems and Solutions Guide - AC Power & Comfort, Inc

Commercial heating, venting, and cooling systems do more than simply regulating the temperatures in the building. If there is a defect in a commercial HVAC system, it can affect the satisfaction and health of the occupants, the productivity level, and the energy bills.

How to Troubleshoot HVAC Problems and Malfunctions

Set the thermostat to "cool" mode. Adjust the thermostat setting 3 to 5 degrees below the room temperature. Locate an open register and check for cool air after waiting for 30 seconds.

Troubleshooting | HVAC Solutions

Because “It’s broken,” never really helps anyone narrow in on the problem, we’ve created an entire troubleshooting hub. From strange noises to no noise at all, these step-by-step guides give you a starting point for identifying the source of your heating and cooling challenge.

How to check if AC is blowing cold air?

AC Not Blowing Cold Air. There are a number of items to check when an air conditioner is blowing but fails to blow out cold air. Make sure the thermostat is set on “auto.”. If it’s on fan, the system will blow air, but may not blow AC air. Check the filters to see if they are dirty.

What to do if your AC isn't running?

Is it plugged in? Is the breaker tripped or is a fuse blown? It may also be a faulty motor or compressor that is preventing the HVAC unit from running properly and continuing to trip an electrical circuit breaker.

Why is my refrigerator low on freon?

If the unit is low on Freon (refrigerant), it may have been undercharged when it was installed or it’s leaking. If it’s leaking, adding more Freon won’t fix the problem for very long. Additionally, Freon leaks are harmful to the environment. It’s thus imperative to inform customers that a Freon leak will require someone who has refrigeration training to test, repair and charge the system.

Why is my HVAC system not working?

Dirty filters and dirty coils are another very common cause of an HVAC system that is not functioning properly. Either of these issues could cause the compressor and fans to fail prematurely.

Why does my AC unit turn off?

When an AC unit is oversized, it could cause the unit to turn off and on too often, resulting in the compressor and fan to wear out more quickly. Another widespread issue is the corrosion of the terminals and wires. An experienced technician should inspect all electrical contacts within the unit.

When did RSI start training HVAC technicians?

If you would like to receive more information about a career in the HVAC industry, contact RSI . We have been training technicians since 1965 and have a number of vocational training programs and course options to help you begin your HVAC career.

Do HVAC technicians need to be certified?

Opportunities for HVAC Technicians. Almost all HVAC repairs will require a certified professional. Choosing a career in this industry would provide you with a job with myriad employment opportunities, as there will always be a need for trained HVAC technicians.

What to do if your compressor won't start?

If your compressor will not start, your first step is to check and see if your unit is receiving power. Examine all the wiring in your HVAC unit, especially the wiring which connects it to an outlet. If you have a blown fuse or a tripped breaker, this may be the end of your search. It is time to bring in an electrician who will help you decide ...

What to do if you notice a problem with your HVAC?

As soon as you notice a problem with your HVAC unit, you should call in a professional HVAC technician to take a look and make any repairs and updates that they deem necessary . Replacing smaller parts as they need them will prevent you from having to replace your entire HVAC unit prematurely.

What is an HVAC Compressor?

Your compressor is a critical part of your HVAC system. In residential units, it is typically located as part of the outdoor unit. The role of the compressor, true to its name, is to compress the refrigerant fluid as it carries heat out of your house. This heats up your already warmed refrigerant fluid even further, converting it from its gaseous form into a liquid.

Why does my HVAC unit make a humming noise?

Your starter relay transfers power from your capacitors to your compressor. If your HVAC will not turn on, but you hear a humming sound from your outdoor unit, it is likely that this is the compressor attempting to access a non-functioning capacitor. Turn your unit off immediately. This can overheat your compressor, causing unit wide damage.

Why does my HVAC unit shut down?

Buildup of dirt and debris in the evaporators, filters or condensers can cause your entire unit to shut down. A clogged filter or register can reduce the airflow so much that your evaporator coil will ice up and stop functioning altogether. Regardless of whether or not this is the source of your current HVAC compressor shut down, keeping this area clean should be a part of your regular maintenance routine.

What happens if your compressor doesn't turn on?

In the worst case scenario, continuous overheating can damage the compressor so much that it may need to be replaced. Go ahead and clean your condenser coils, replace or wash your filters and make sure the supply vents are clear of blockages. If your compressor still does not turn on, it may be time to bring in an HVAC technician. ...

Is it important to keep refrigerant at a higher temperature?

Though purposefully adding further heat may seem counterintuitive, it is important that the refrigerant be at a higher temperature than the outdoor environment. Especially if you live in areas where summer days can reach up to 120 degrees Fahrenheit. This taps in to a basic rule of physics: Heat will always transfer from warm to cool areas. To ensure that the heat your refrigerant fluid is carrying outside is transferred efficiently out of your home, it is crucial that your compressor be well maintained and in working order.

How do you know if a condenser has power?

You know the condenser has power because the fan is running. Make sure to turn the power off before troubleshooting the compressor.

How many windings does an electric compressor motor have?

A compressor electric motor has two separate windings inside for the average residential air conditioner or heat pump single-phase compressors. The windings inside the compressor are the run winding and the start winding. When troubleshooting an air conditioner or heat pump compressor one should see three terminals on the outside of the compressor.

How many terminals are there on an air conditioner?

When troubleshooting an air conditioner or heat pump compressor one should see three terminals on the outside of the compressor. These three electrical terminals are called or should be labeled in some manner.

Why does my condenser make a loud noise?

This sounds like a mechanical issue but could be an electrical issue. Follow the troubleshooting steps above to figure out what the compressor problem is and repair it. Many times, when you hear a loud humming noise coming from a condenser the noise is created by the compressor contactor. If it is too annoying, replace it.

Why is my ohm meter reading zero?

The problem usually occurs because the insulation on each winding has dissolved, allowing the copper windings to touch each other. Your Ohm Meter will likely read zero in this instance. Furthermore, the compressor is bad if you get this reading.

Can a scroll compressor unload?

There are new scroll compressors out that can unload. Other electronic scroll and rotary compressors can fully modulate. This article does not address these newer compressors. Copeland initially owned scroll compressors and the scroll technology. Emerson Electric owns Copeland. There are also inverter duty compressors in some split system air conditioners and heat pumps. Nordyne et al. manufacture those compressors. And are different than the compressors we are talking about here. These newer systems require a different compressor troubleshooting analysis and technique than described here. The newer modulating systems are now in many different brands of HVAC equipment. Lastly, they use rotary compressors.

Can an air conditioner compressor be repaired?

Furthermore, the only visible working parts on the compressor are the electrical connections and the copper discharge and suction lines. That makes it difficult to repair any compressor once a diagnosis is made to the air conditioner or heat compressor.

How to check AC compressor wiring?

The main tool used to check AC condenser components is an electric multimeter. Troubleshooting AC compressor wiring requires one. If you have a multimeter and know how to use it, locate the C, R and S terminals. Check for continuity between C & R, C & S and R & S. Resistance should be less than 30ohms.

How to stop a compressor from starting?

Check to see if the condenser fan at the top of the condensing unit starts. A condenser fan motor that is locked up will prevent the compressor from starting.

Why is my compressor hard to start?

Internal fuses and faulty wiring are the most common causes of hard starting. If you’ve ruled out those causes, adding a hard-start capacitator that gives the compressor additional torque to get started might work. These devices are helpful when an aging capacitor needs a boost.

Why is my AC compressor not charging?

Solution: If you’ve already checked the filter and evaporator coil, then the system might not have sufficient refrigerant charge. A leak is the most common cause of this issue. Troubleshooting AC compressor leaks is difficult without training and the right equipment. Repairing and recharging the system requires a refrigerant handling license.

What to look for when checking AC continuity?

While checking continuity, look for obvious signs of loose, broken, chewed or burned wiring. If there’s continuity and no obvious wiring issues, then troubleshooting AC compressor issues is the next step.

Why won't my AC compressor start?

Symptom: The compressor won’t start or stops shortly after starting. Solution: The most common cause of this issues is a failed start capacitor. Replacing it is one of the simpler AC compressor repair issues. If replacing the capacitator doesn’t help, the compressor motor is probably wearing out.

What causes an AC compressor to turn off?

Here are common AC compressor problems and what causes them. 1. Check Fuses and Wiring. Symptom: The AC turns on and off frequently. Solution: Known as hard starting and short cycling, this problem prohibits adequate cooling and will quickly ruin the compressor.

Why does my compressor overheat?

It’s caused by refrigerant wearing out the oil, creating a situation where copper plating occurs. From there, the compressor overheats and draws higher amps.

What to do if fan isn't working?

If the fan isn’t working, troubleshoot the fan. You may have to replace the fan motor, cool down the compressor until it’s ready to run again, and retest the system. Rarely do I find the condenser fan motor, and the compressor will have gone bad on the same day. But I guess it can happen.

Why did the compressor internal overload switch open in the first place?

Why did the compressor internal overload switch open in the first place? A bad capacitor or hard start kit can cause the compressor windings to overheat or just not start at all. So before we diagnose a bad compressor, we should make sure our capacitors are good.

Can you get into a hermetic compressor?

Hermetic compressors like the ones we work on in residential HVAC are sealed. So, we can’t get into them to make any repairs.

Do scroll compressors have valves?

Something I hear technicians say a lot is the compressor has a bad valve. Well, today’s scroll compressors don’t have valves. They do have bearings that can go bad! But valves were an issue with reciprocating compressors in earlier models.

Can you run a compressor with a fan?

Another thing you can try is, removing the wires from the compressor altogether and just run the outdoor unit with the fan only. If the fan works, great. You can move on. You know it’s not the fan tripping the breaker.

How to tell if your AC compressor is bad?

Think of your air conditioner’s compressor like the heart of the machine. If it isn’t working well, the rest of your air conditioning system will run out of sync. Before your air conditioner fully breaks down, keep a lookout for these signs there may be an AC compressor failure: 1 The AC compressor won’t turn on 2 The air conditioner is blowing warm air 3 The air conditioner frequently trips the circuit breaker 4 The outside unit shakes when it starts up 5 The air conditioner is making strange noises

What happens if your AC compressor fails?

Although the compressor is only one of the three major components of your air conditioning system, if it fails, your entire air conditioning unit will not produce cool air effectively. If you have any questions about troubleshooting your AC compressor ...

Why is my air conditioner not starting?

If the compressor isn’t starting, your air conditioner may be low on refrigerant, and the compressor may be too hot or broken. Inspect the fan motor – Next, take a look at the fan motor because it can affect the compressor too. For example, a fan motor may lock when it is running, or it may have poor wings.

Why is my compressor breaking?

A few key things could be the cause of your compressor breaking: the wrong amount of refrigerant, dirty or frozen coils, or contamination. Let a professional HVAC company determine the cause of your breakdown and make the correct repairs.

How to contact AC repair Middle Georgia?

If you have any questions about troubleshooting your AC compressor problems or if you’re interested in scheduling AC repair in Middle Georgia, give us a call at (478) 787-6578 or contact us online today.

How to check if AC is blowing cold air?

AC Not Blowing Cold Air. There are a number of items to check when an air conditioner is blowing but fails to blow out cold air. Make sure the thermostat is set on “auto.”. If it’s on fan, the system will blow air, but may not blow AC air. Check the filters to see if they are dirty.

What to do if your AC isn't running?

Is it plugged in? Is the breaker tripped or is a fuse blown? It may also be a faulty motor or compressor that is preventing the HVAC unit from running properly and continuing to trip an electrical circuit breaker.

Why is my refrigerator low on freon?

If the unit is low on Freon (refrigerant), it may have been undercharged when it was installed or it’s leaking. If it’s leaking, adding more Freon won’t fix the problem for very long. Additionally, Freon leaks are harmful to the environment. It’s thus imperative to inform customers that a Freon leak will require someone who has refrigeration training to test, repair and charge the system.

Why is my HVAC system not working?

Dirty filters and dirty coils are another very common cause of an HVAC system that is not functioning properly. Either of these issues could cause the compressor and fans to fail prematurely.

Why does my AC unit turn off?

When an AC unit is oversized, it could cause the unit to turn off and on too often, resulting in the compressor and fan to wear out more quickly. Another widespread issue is the corrosion of the terminals and wires. An experienced technician should inspect all electrical contacts within the unit.

When did RSI start training HVAC technicians?

If you would like to receive more information about a career in the HVAC industry, contact RSI . We have been training technicians since 1965 and have a number of vocational training programs and course options to help you begin your HVAC career.

Do HVAC technicians need to be certified?

Opportunities for HVAC Technicians. Almost all HVAC repairs will require a certified professional. Choosing a career in this industry would provide you with a job with myriad employment opportunities, as there will always be a need for trained HVAC technicians.