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Ruud Air Conditioner: Complete Troubleshooting Guide

Ruud air conditioners are great machines, but even the best AC units can have trouble from time to time.

If you’re experiencing Ruud AC issues, don’t worry! This is a complete troubleshooting guide for the Ruud air conditioner issues. You’ll find causes and solutions for any problem that your Ruud AC might be presenting. Let’s go!

Ruud Air Conditioner Not Cooling

If your Ruud Air Conditioner is not cooling, the issue might be clogged air filters, a faulty thermostat, a faulty compressor, refrigerant leak, or dirty condenser coils. The most common cause for a Ruud AC not cooling is clogged air filters, which you can fix by cleaning or replacing the filters.

Clogged Air Filters

Is your Ruud AC air filter dirty? A dirty and clogged air filter slows down the flow of air into your Ruud cooling unit. 

This reduces your AC’s cooling capacity significantly and will eventually make the AC’s evaporator coils frost over, another cause of a non-cooling Ruud AC.

How To Identify Clogged Air Filters

Air filters are found in a filter cabinet on the side or bottom of the unit depending on the make. To check if your Ruud air filter is dirty, remove the front cover of the cabinet and check if the filters are filled with debris.

How To Fix Clogged Air Filters

Depending on your Ruud AC series and if your AC has permanent Ruud filters or replaceable ones, you have the option to clean or replace dirty air filters. 

To replace a dirty Ruud AC filter:

  1. Turn off the AC’s power. Wait 30 minutes for the internal parts to cool.
  2. Open the panel that covers the filter.
  3. Find the air filter near the return air duct and carefully remove it.
  4. Dust the area around the filter with a soft cloth while you are at it so the new filter does not suck back any dirt from inside the AC.
  5. Grab your new air filter and put it where the old one was ensuring it stays well in place.
  6. Replace the cover panel.
  7. Turn your AC’s power back on.

To clean a permanent Ruud filter:

  1. Turn off the AC’s power and wait 30 minutes for the internal parts to cool.
  2. Open the panel that covers the filter.
  3. Find the air filter near the return air duct and carefully remove it.
  4. Use a soft brush and warm water with a mild kitchen detergent to clean the filter and rinse it in a sink or tub.
  5. Leave the filter to dry completely.
  6. Dust the area around the filter with a soft damp cloth while the filter dries. This will prevent the cleaned filter from sucking any dirt from other internal parts.
  7. Grab the clean and dry air filter and put it back in the AC, ensuring it stays well in place.
  8. Replace the cover panel.
  9. Turn your AC’s power back on.

Faulty Thermostat

The thermostat is the part of your cooling system that monitors the temperature of the air in your home. 

Depending on how it’s set, the thermostat will activate a switch to power the fan and compressor when the temperature in the air rises above the set point.

However, if the thermostat of your HVAC system is faulty, it will not perform this function properly and your AC will not cool.

How To Identify A Faulty Thermostat

Normally, your Ruud AC will display an error if the thermostat is malfunctioning. A status LED that shows Yellow “ALERT” Flash Code 1 error points to several Ruud AC issues including a malfunctioning thermostat.

If there’s no error code but you still think your AC’s thermostat could be malfunctioning, assess your thermostat by:

  1. Ensuring the AC is set to ‘cooling’ and not to ‘auto’.
  2. Using a multimeter to check the thermostat for continuity (complete path of current flow).

How To Fix A Faulty Ruud AC Thermostat

It would be easy to fix a thermostat if the only issue is an ‘auto’ setting that simply needs to be set to ‘cooling’.

But, if your thermostat is set to cooling and you test your thermostat with a multimeter for continuity and there is no sign of a complete path of current flow, you will most likely need to replace the thermostat.

The best decision is to call an HVAC technician to confirm your findings since thermostats that also control a heater have 3 terminals and could have issues with any of these.

Refrigerant Leak

During the cooling process, the refrigerant in copper coils flows through the AC to absorb heat from indoor air and dispense it from the air in the cooling chamber. 

If your AC has a refrigerant leak due to cracked or worn-out refrigerant coils, it will have a low refrigerant charge, which means it will not be blowing cold air

How to Identify a Ruud AC with Refrigerant Leak

An AC that’s low on refrigerant can show one of these four signs:

  • Not blowing cold air.
  • Frozen refrigerant lines.
  • Longer cooling cycles.
  • High energy bills from overworking.

Your Ruud AC will also show a low refrigerant error, Yellow “ALERT” Flash Code 1 on the status LED. The description for this error is that the compressor is running extremely long cooling cycles which is indicative of low refrigerant charge among other possible issues.

How to Fix a Ruud AC with Refrigerant Leak

A refrigerant leak should only be attended to by a licensed technician. Fill out the form at the end of this article and let us connect you to a Ruud AC expert.

Note also, that though uncommon, an AC may have been undercharged with refrigerant from the beginning, which is another reason AC refrigerant issues should be attended to by a pro. 

Dirty Condenser Coils

AC condenser coils dispel the heat as the refrigerant flows through the coils. If the coils are dirty, the heat will not be dispelled as it should, compromising the working and efficiency of your AC, including not blowing cold air.

How to Diagnose Dirty Condenser Coils

To check whether the condenser coils are dirty, remove the front cover of your Ruud AC then check to see if the filters are dirty and if so, proceed to clean them.

How to Clean Dirty Condenser Coils

To clean your Ruud AC condenser coils, follow these steps:

  1. Turn off your AC and wait until it has cooled.
  2. Remove the outer casing.
  3. Remove the screws that attach the protective lid to the rest of the condenser, this will help you reach the condenser fins easily. If you aren’t able to do this, you should call a professional HVAC for the job.
  4. Use a vacuum with a soft brush attachment to loosen and remove debris from the condenser fins. Avoid hard brushes as the fins are fine and delicate.
  5. Use a hose to spray the fins with water from the inside to the outside so that any remaining dirt is removed. Ensure the hose has a gentle setting to avoid ruining the condenser fins. Also, be careful not to soak any of the electrical components.
  6. Allow the condenser and any parts that got water to dry completely.
  7. Once dry, put back the filter and outer cover then turn your AC back on.

Note that this process may not be as easy as it sounds. If you have any doubts, don’t feel up to the task, or are afraid to damage your cooling unit, fill the form at the end of this article and we’ll send an HVAC expert your way to do a thorough cleaning of the condenser coils.

Ruud Air Conditioner Not Turning On/Not Working

If your Ruud air conditioner is not turning on, it has issues with the power supply which could be caused by a bad control board or a burnt run capacitor. Both parts will need to be replaced. 

Bad Control Board

The control board regulates the supply of power to the fan motor and the compressor. If it fails, the control board will not send the right voltage to these AC parts and your cooling system won’t turn on.

How to Diagnose a Bad AC Control Board

Diagnosing a failed control board requires the use of tools like a voltage meter, screwdriver, and electrical tape. 

Basically, it has to do with picking the right electrical wires and testing the flow of power. As such, diagnosing a bad AC control board is best left to a trained HVAC expert to avoid damage to the cooling unit and the risk of any unintended accidents.

How to Fix a Bad Control Board

Homeowners often misdiagnose a good control board for a failed one. So, even if you are sure that the control board is bad, the best thing to do is to call a reliable Ruud HVAC service. 

The HVAC expert will rule out all other common causes of an AC that won’t work before deciding that the control board needs replacement.

Burnt Run Capacitor

In a cooling unit, the run capacitor is connected to the compressor through electrical leads. Its function is to deliver the surge power that turns on the system at the beginning of a cooling cycle and then keep the system running with a continuous power supply until the cooling cycle is complete.

If your Ruud AC capacitor is burnt, it will not supply the surge power and the compressor won’t turn on.

How to Diagnose a Burnt AC Capacitor

Capacitors are linked to the compressor, which is the heart of the cooling system, and it’s best not to do a try and error diagnosis.

Instead, call an HVAC technician to test the AC capacitor for continuity using a multimeter (multitester/VOM) as seen in this video

Allow us to connect you to a reliable HVAC pro by filling the form at the bottom of this article.

How to Fix a Burnt AC Capacitor

Once you bring in an HVAC expert and it is concluded that your Ruud AC capacitor is indeed burned, the AC expert will replace it.

Ruud Air Conditioner Fan Not Spinning/Not Working

A Ruud air conditioner fan that’s not spinning could be caused by a defective or worn out fan motor, a malfunctioning thermostat, a bad control/relay board, or a bad rotary switch. The most probable cause is a defective fan motor which should be assessed and replaced by an expert HVAC pro.

Defective/Worn-out Fan Motor

The fan in your AC is an air mover that sends out hot air allowing the cool air to be sent to your home through the duct. 

If the motor of your AC fan is defective or does not work due to wear and tear, the fan will not spin to perform its air moving job.

How to Diagnose a Defective/Worn out Fan Motor

A Ruud AC fan that is not running can be announced by a Yellow “ALERT” Flash Code 2 error on the status LED.

But, to check whether the motor of your AC fan is defective, try turning the fan blade by hand. If it doesn’t turn easily, the bearings of the motor are most likely worn out.

If you try turning the fan blades by hand and they turn freely, check the fan for current flow. If there’s an indication that power is flowing to the fan motor but it won’t run, the fan motor is defective.

How to Fix a Defective/Worn out Fan Motor

The best thing to do if the above diagnosis suggests a defective/worn-out fan motor is to call a trained HVAC expert to replace it.

Malfunctioning Thermostat

When the air temperature in your home rises above the set level, the thermostat sends a signal to the fan and compressor to start running. 

If this signal is not sent because your AC thermostat has malfunctioned, neither the fan nor the compressor will run.

How to Diagnose and Fix a Malfunctioning Thermostat

See how to diagnose and fix a faulty AC thermostat in the previous section on “Ruud Air Conditioner Not Cooling”

Bad Control/Relay Board

Control and relay boards supply voltage to other parts of the cooling system including the air conditioner fan.

If any of these boards are not working properly, the voltage will not be supplied and the fan will not work.

How to Diagnose and Fix a Bad Relay/Control Board

A faulty relay/control board will have to be replaced. Since it’s common to misdiagnose relay/control boards, an expert HVAC pro should be contacted to test a relay/control board for faults. Doing so involves identifying the right connecting and testing for continuity with a voltmeter. 

Bad Rotary Switch

An AC rotary switch rotates to control circuit functions in a fan motor. With wear and tear, the electrical contacts of a rotary switch can be eroded and electrical conduction reduced.

How to Diagnose and Fix a Bad Rotary Switch

A multimeter is needed to determine if there’s continuity in the rotary switch. You can refer to the wiring diagram in your Ruud AC user manual to do this. But, in my experience, those diagrams are as clear as mud.

The safest option is to have a trained HVAC handle the task. Besides, a bad rotary switch will have to be replaced, and you don’t want to be chancing on that.

Ruud Air Conditioner Won’t Turn Off

A Ruud AC that won’t turn off has dirty evaporator coils, a short-circuited temperature control thermostat, or a malfunctioned control board. A dirty evaporator coil is the most common cause for a Ruud AC that won’t turn off, but this can be easily reversed by cleaning the coil. 

Short-circuited Temperature Control Thermostat

The thermostat controls the cooling cycles of your AC by igniting the voltage to run the compressor and fan when the temperature in the ambiance is higher than the set temperature.

If the temperature control thermostat has short-circuited, it could continuously send voltage to the compressor and make it run without turning off. 

How to Diagnose a Short-circuited Temperature Control Thermostat

To determine if the temperature control thermostat of your cooling system has shorted, you’ll need a multimeter to detect continuity. 

A thermostat that shows continuity all the time has short-circuited.

How to Fix a Short-circuited Temperature Control Thermostat

A short-circuited temperature control thermostat should be replaced. Seek the service of a reliable HVAC expert to do the job.

An expert HVAC will also decide what’s best to do if the same thermostat controls the furnace and has 3 terminals.

Malfunctioned Control Board

The control board sends voltage to all the parts of your AC. If it malfunctions, it might continuously provide power to the compressor and fan and cause them to run continuously. 

How to Tell if your AC Control Board has Malfunctioned

If you or an HVAC expert has checked the cooling unit for other causes of an AC that won’t turn off, it’s most likely that the control board has malfunctioned.

How to Fix an AC Control Board that has Malfunctioned

A malfunctioned AC control board will need to be replaced. Get the job done straight away by filling the form at the end of the article and we’ll send you reliable HVAC service immediately.

Condenser Coils are Dirty

Dirty condenser coils do not dissipate the heat in the refrigerant. This causes your AC to run continuously in an attempt to meet the temperature requirements.

Read how to diagnose and fix dirty condenser coils in the earlier section on “Ruud Air Conditioner not Cooling.”

Ruud Air Conditioner Leaking Water

A Ruud air conditioner that’s leaking water has a blocked condensate drain, dirty or frozen evaporator coils, or the AC is badly installed. A blocked condensate drain is the most common cause for a Ruud AC leaking water and can be resolved by draining the standing water and unclogging the drain.

Blocked Condensate Drain

The cooling process produces moisture as a byproduct. As the air circulates in the evaporator coils, dust and dirt can be trapped in the moisture and then carried into the condensate drain. 

Dirt build-up in the condensate drain eventually creates blockage and an overflowing drain pan. An overflowing condensate pan will send water to the floor or back to parts of the cooling unit.

How to Diagnose a Blocked Condensate Drain

The first sign in telling a blocked condensate drain is the leaking/standing water near the cooling unit. Additionally, you will notice these signs as well:

  • A moldy/musty smell near the unit or in the air from the vents.
  • Water damage on walls and in areas around the cooling unit.
  • A faulty AC: not cooling or short cycling (the AC’s cooling cycle becomes shorter than the standard 10 minutes, making the compressor turn on and off more often than it should.

How to Fix a Blocked Condensate Drain

The HVAC expert should inspect and clean your cooling unit’s condensate drain during the annual maintenance tune up. 

If this service is skipped, your AC could face a condensate drain clog which you or a trained HVAC pro can clear in the following steps: 

  1. Power off the AC.
  2. Locate the drain pan and notice any standing water. Empty the standing water by soaking it with a rag.
  3. Use a shop vacuum or a wet vac to suck up any water and debris from the condensate drain. You could also use a plumber’s snake to remove any objects clogging the drain.
  4. Pass a bucket of warm water with a bit of distilled vinegar and kitchen detergent to clear the drain of any dirt that’s sticking to the pipe.
  5. Reinstall any parts that were disassembled during the cleaning.
  6. Power on the AC and check if the issue is resolved.

Dirty or Frozen Evaporator coil

If the moisture leak from your Ruud AC is presenting as sweat on the outside of the unit, the AC evaporator coil could be frozen. This is usually caused by dirty coils or a low refrigerant level.

Alternatively, the dirty coils are preventing proper moisture drainage and sending it to other AC parts and not to the drain pan. 

How to Diagnose Dirty/Frozen Evaporator Coils

Here’s what you need to do to check if your evaporator coils are frozen: 

  1. Check the outdoor refrigerant line for signs of frost.
  2. Look around the AC casing and other parts for moisture and condensation.
  3. Check if the drain pan is consistently full and overflowing and rule out a blocked condensate drain.
  4. Open the AC evaporator compartment by removing the outer covering panel. Then proceed to remove the filter and inspect the evaporator coil for freeze up or dirt.

How to Fix Dirty/Frozen Evaporator Coils

If you notice any signs that the evaporator coil is frozen, turn off your AC and the circuit breaker box and allow the ice to thaw. You may want to set your AC to the FAN mode at the thermostat to speed up the thawing process. 

If the evaporator coil is dirty, follow these steps to clean it:

  1. Mix water with a liquid evaporator cleaner in a spraying bottle. (You may also opt for a no-rinse foam coil cleaner in place of the water-coil cleaner solution, especially if you have a high-wall AC. See this video for a demonstration).
  2. Use a shop vacuum to remove the heavy dirt and debris first.
  3. Spray the evaporator coils generously with the solution so that all the dirt is soaked and washed away.
  4. Spray water to rinse. This will ensure any remaining dirt is eliminated. 
  5. Pass a soft cloth to dry the water around the unit and pick any remaining dirt.
  6. Replace the air filter. Be sure to put back a clean air filter.
  7. Place back the outer cover of the unit and check if the leaking problem is resolved.

Bad AC installation

Depending on the model, your Ruud AC may be designed for vertical or horizontal installation. If this is not done as intended, water may leak from the drain pan.

Also, if your through-wall or window air conditioner is leaking from the front, it could be that it is leaning forward more than it should.

How to Diagnose Bad AC Installation

Air conditioners expel moisture from the back of the unit to a drain pan and out through the drain.

If your AC is leaning forward rather than to the back on a 1° to 2° angle, then the moisture will leak from the front. 

How to Fix a Bad AC Installation

Your cooling unit installer should follow the information in the Ruud AC Installation Instruction Manual that comes with the unit and refer to the applicable Engineering Specification Sheet.

Any indication that bad installation was done should be corrected by a reliable HVAC technician.

Ruud Air Conditioner Freezes Up

A Ruud air conditioner freezes up due to dirty evaporator coils, refrigerant issues, airflow problems, low temperatures, and drainage issues. A dirty evaporator coil is the most probable cause for a frozen Ruud air conditioner and can be resolved by turning off the AC and allowing the ice to thaw.

Dirty Evaporator Coils

The work of the evaporator coils is to transfer refrigerant to the heat pump. 

If there’s dirt build-up on your AC evaporator coils, it will have to work harder, which puts the evaporator coils at the risk of freezing up because heat absorption is not happening as it should.

See how to diagnose and clean dirty evaporator coils in the earlier section on “Blocked Condensate Drain.”

Refrigerant Issues

The refrigerant in your AC runs in a closed system and should not need to be replaced unless it was wrongly charged from the beginning, which is rare. 

However, if the copper coils are worn out and have cracks or holes that cause a refrigerant leak, your cooling system will be low on refrigerant charge.

As a result, your Ruud AC will have to work extra hard to meet the required temperature levels, again with the risk that ice builds up on the evaporator coils.

How to Diagnose and Repair Ruud AC Refrigerant Issues

This is not a DIY issue. You will need to call in a reliable HVAC service to assess your cooling system and restore the required refrigerant levels or replace worn-out copper coils.

If your unit has done a minimum of 10 years, the HVAC expert will advise you to replace the cooling unit instead of the coils.

Airflow Problems

Improper airflow is one of the main causes of a frozen AC. It is mostly caused by dirty air filters but can also be caused by the following issues: 

  • Wrong-sized air filter.
  • Narrow or damaged ductwork.
  • Blocked vents and registers.
  • A faulty blower motor or fan

How to Diagnose AC Airflow Problems

An AC with airflow issues will blow little or no cool air. The little incoming air will also make your AC work continuously to try and meet the temperature levels.

So, if your Ruud air condition is not cooling or is blowing little cool air, you could have airflow issues from any of the listed causes.

How to Fix AC Airflow Problems

The only way to fix AC airflow issues is to address the root causes:

  • Clean/replace dirty air filters.
  • Have an expert HVAC technician repair damaged ductwork or replace narrow ductwork with the recommended size.
  • Unblock clogged vents and registers.
  • Contact an HVAC pro to replace/repair a faulty blower motor.
  • Ensure no objects are on the way to incoming air (furniture of foliage depending on your AC set up).

Low Temperatures

Air conditioners are designed to run under specific temperature ranges, usually above 60°F. If your Ruud AC is running under this temperature, the pressure inside your cooling unit will go down and the evaporator coil in your air conditioner can freeze.

What to Do when Temperatures are Unfavorable to Run the AC

Check that the temperature levels are above 60°F before starting to run your AC in the warm season.

If temperatures are around the 60°F range, avoid running your AC during the night when temperatures drop.

Program your thermostat to 78°F while at home and 84°F when you are away so it does not run under low temperature ranges.

Drainage Problems

Especially if you are in a location with high humidity, your AC evaporator coil will work extra hard to remove the moisture in the air and cause condensation out of the home. 

If you have a clogged condensate drain, this extra moisture will hang around the cooling unit and can freeze the evaporator coil.

How to Fix AC Drainage Problems

Read about how to fix a blocked condensate drain in the earlier section on “Ruud AC Leaking Water.”

Also, ensure you run a dehumidifier in your air-conditioned home if the air is registering high humidity levels. This will prevent your evaporator coil from working extra hard.

Ruud Air Conditioner Compressor Not Running

If your Ruud air conditioner compressor is not running, the compressor or parts connected to it could be defective, the temperature control board could be faulty, or the thermostat could be malfunctioning. A defective compressor is more common and will require a trained HVAC to replace it.

Faulty Temperature Control Board

An AC temperature control board provides power to the compressor and the fan. If the control board is faulty, the voltage will not be sent and the compressor won’t run. 

How to Diagnose and Fix a Faulty AC Temperature Control Board

You’ll need a voltmeter to test electrical flow in the wires that supply voltage to the compressor. Since this is a delicate task, it is best handled by a trained HVAC expert.

Also, a faulty temperature control board will most likely need replacement, and that’s best decided on by an AC pro.

Fill out the form at the bottom of this article and we’ll send you a reliable Ruud HVAC expert to assess and fix control board issues.

Defective Compressor/Compressor-connected Parts

Your AC compressor may fail to run if it is defective or parts connected to it are defective including the selector switch, capacitor, and compressor overload.

How to Diagnose a Defective Compressor/Compressor-connected Parts

Desist from DIY solutions for issues related to the compressor. The compressor is the heart of your cooling system and cannot be dealt with from a hit or miss approach. 

By filling the form at the end of this article, we’ll send you a reliable HVAC technician who will perform the following:

  1. Test the compressor for continuity.
  2. Test the selector switch, capacitor, and compressor overload for continuity.
  3. Rule out any other issues causing your compressor not to run.
  4. Replace a faulty compressor.

Faulty Thermostat

As indicated earlier, the thermostat monitors the temperature of the air in your home and tells the compressor and fan to start the cooling process once the set temperature is surpassed. 

If your Ruud AC thermostat is defective, it will not detect temperature changes and will, therefore, not activate the compressor.

Read how to diagnose and fix a faulty Ruud AC thermostat in the earlier section on “Ruud Air Conditioner not Cooling.”

Ruud Air Conditioner Making Loud Noise

There are two AC issues that will cause your Ruud air conditioner to make loud noises: a worn-out compressor and a defective Fan/Fan blower motor. A defective fan or fan blower motor may happen more often and is best attended to by an HVAC pro. 

Worn Out Compressor

If you have an old Ruud AC and the compressor is beginning to wear out, it will produce unusual loud noises.

What to Do with a Noisy Worn out AC Compressor

Have an HVAC professional determine if wear and tear are the reasons your compressor is making loud noises and advise you if it’s time to replace your cooling unit.

Defective AC Fan Parts

The fan and compressor are the most active parts of your cooling system. Since your fan is always blowing when your AC is on, wear and tear are possible occurrences. 

Some of the issues that will cause your fan to make loud noises include:

  • Break down in the lubrication of the bearings of the fan motor.
  • Damaged fan blade or one that is rubbing against the fan casing.
  • A loose blower wheel that’s wobbling on the motor shaft.

How to Diagnose Defective AC Fan Parts

Your Ruud AC may show a Yellow “ALERT” Flash Code 2 error on the status LED if your AC fan is defective. 

If that’s not the case and you are guessing that your AC has fan issues, open the AC compartment where the fan is housed and wiggle the blower wheel to see if it turns and turn the fan blades to see if they rotate easily.

How to Fix Defective AC Fan Parts

A loose and wobbling blower wheel can be easily fixed by tightening the screws. But, fan blades that do not turn easily will most likely have worn-out bearings in the motor. 

Call an HVAC pro to fix or replace your defective AC fan parts.


Unless it’s an easy-to-fix Ruud AC issue that does not create the risk for further damage if you DIY, always seek the services of a reliable HVAC expert to diagnose and fix problems with your Ruud AC.

We’ve got your back and will send you a licensed HVAC professional once you fill the form at the bottom of the article.


  • Alanna Greene

    Alanna is an avid traveler who lives in Michigan. In addition to writing for Temperature Master, he also sells crafts on Etsy and takes long walks through the forests near her home.

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