
Carrier air conditioner error code U3
- Remove the 4-way valve coil Remove the screws on the fixed coil by using a screwdriver. Remove the 4-way valve coil.
- Remove 4-way valve Reclaim all refrigerant charge in system. Cut all line connections to 4-way valve and remove from unit.
- Replace the 4-way valve Place the new 4-way valve in the right place. ...
- Install the 4-way valve coil
Full Answer
Why is my carrier air conditioner not cooling?
- Make sure the mode switch or selector switch is set to HIGH HEAT and the temperature control is set to a higher number.
- Make sure the air filter has been cleaned in the last 30 days. ...
- Make sure nothing is blocking the air flow coming from the air conditioner such as furniture, drapes or lamps.
How to troubleshoot a carrier air conditioner unit?
Carrier AC Problem: Cooling is Not Working Properly Carrier AC Possible Cause:-The filter is blocked with dust-Temperature is not set properly-A window or door is open-The outdoor unit is obstructed-The fan speed is too low-The operation mode is in Fan instead of Cool Carrier AC Solution:-Clean the air filter-Check the temperature and reset if necessary-Close the window or door-Remove the obstruction-Change the fan speed selection-Change the operating mode to Cool or reset the unit
How much does a carrier air conditioner cost?
It also depends upon the type of system. Carrier ® air conditioners, for example offer a variety of energy efficiency or SEER* ratings, various types of comfort-enhancing technologies and even sound ratings. Installed costs might range from anywhere between $3,000 to $15,000 or more. That’s quite a range!
Should you call for air conditioner repair?
When your heating and cooling system isn’t working properly, you might throw up your hands and call for help, thinking the solution must be outside your skill set. You might be surprised to ...

How do I fix my Carrier air conditioner?
0:171:53carrier air conditioner troubleshooting - YouTubeYouTubeStart of suggested clipEnd of suggested clipCover busted motor turn the unit back on and listen for any other strange noises. Make sure that theMoreCover busted motor turn the unit back on and listen for any other strange noises. Make sure that the blades are spinning properly.
Is there a reset button on Carrier air conditioner?
Carrier air conditioning units usually will have a reset button on them. You can find the reset button inside the air conditioner's compressor. The button is red in color and fairly small in size.
Why is my Carrier Aircon not working?
Issues that can lead to a frozen evaporator coil include: Excessive buildup of dust, dirt or other pollutants on the evaporator coil. Excessively dirty or clogged air filter. Excessive buildup of dust, dirt or debris on the outdoor condensing unit.
Why is my AC running but not cooling?
If you're experiencing AC not cooling while the system is powered on, you could have a clogged or blocked coil. Unfortunately, a wide variety of debris can find its way into this equipment, including grass, dirt, and other contaminants. This can result in a serious clog, which can lead to a system malfunction.
How do I reset my AC 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.
How do I reset my carrier control board?
Here is how you can reset it using the button:Look under the digital display of the unit. There, you will be able to find a control panel with the small "Reset" button.Press and hold for 3 seconds, then release. ... Wait for a flash of light to appear.Wait for a few seconds and observe if this solves the technical issue.
Where is the reset button on my carrier thermostat?
Carrier Cor thermostatTap the "Main Menu," then "Settings," and finally "Reset" to get started.Now choose the appropriate option from the reset menu.To continue to the confirmation of the reset, touch the "Yes" button.
How do I reset my AC breaker?
How do you reset your AC unit?Turn off your air conditioning system using the thermostat. ... Search for the breaker box. ... Shut off your AC unit at the breaker. ... Wait at least a full minute before switching the breaker back to the “on” position.Wait for 30 minutes before turning your unit back on at the thermostat.More items...•
Why is my outside unit not turning on?
AC not turning on could be the result of a blown fuse located at something called a safety shut-off box. This should be found close to your AC unit. Check to see if you have a blown fuse, and be sure to replace it if that's the case. Even if the fuse doesn't appear to be damaged, go ahead and replace it anyway.
How to troubleshoot an air conditioner?
Knowing how to troubleshoot an air conditioner often starts with the main control – its thermostat. Thermostats come in a variety of options, starting with very basic models that simply control heating and cooling temperatures and fan operation. More sophisticated programmable versions can be set to automatically change temperatures throughout the day for better comfort when you are home, and higher efficiency when you are at work or asleep at night. Wi-Fi® models can be controlled from a mobile device or computer anywhere you have access to the internet. Considering all of the options available, there are a number of ways your thermostat settings can make it appear that your air conditioner is not running correctly. Symptoms you might notice include:
What to do when central air is not cooling?
And sometimes when it’s not cooling adequately your first instinct is to call an HVAC technician for air conditioner service. But before you pick up the phone, take a few moments to play detective.
How does refrigerant work in an air conditioner?
The refrigerant is pumped through copper tubing, the indoor evaporator coil and outdoor condensing unit, in a continuous loop. As it flows through your AC system, the refrigerant pulls heat from your home and deposits it outside, leaving indoor air cooler, less humid and more comfortable.
Why is my condensing unit not turning on?
Condensing unit not turning on at all. As was the case with evaporator coil issues, a condensing unit might have an excessively dirty coil or refrigerant leakage. Additional issues with the outdoor condensing unit might include a faulty compressor, a failing condenser fan motor, or a faulty run capacitor.
What causes a copper evaporator coil to freeze?
Issues that can lead to a frozen evaporator coil include: Excessive buildup of dust, dirt or other pollutants on the evaporator coil.
Why does my AC turn on and off?
AC turning on, then off quickly, several times in a row (short cycling) If your thermostat settings are correct and your air filter is clean, you may have a leak or other issue that is causing the refrigerant levels to drop. If you suspect low refrigerant levels, contact your local Carrier dealer.
What is an AC system?
Your AC system is more than just the outdoor unit sitting by the side of your home. Most systems also include an indoor air handler unit, usually a furnace or fan coil. The indoor unit should include an air filter that traps dust, dirt and other airborne particles.
How long is a carrier air conditioner warranty?
All Carrier air conditioners are backed by an excellent warranty that includes a 10-year parts warranty and a 10-year compressor warranty.
Who made the first air conditioner?
Carrier has been in the HVAC business since 1902, and they’re credited with designing the first modern air conditioner. They are one of the most well-recognized brands in Canada’s HVAC industry, and they’ve been making reliable cooling and heating systems for over a century.
What to do if AC drain line is clogged?
If you have a situation with a clogged air conditioner drain line and you have exhausted the troubleshooting steps outlined previously, it’s time to schedule an appointment with a certified HVAC technician. Your local Carrier HVAC dealer offers the expertise needed to properly diagnose and service your AC system.
What happens when air is trapped in evaporator coil?
As indoor air circulates through the evaporator coil, dust, dirt and other airborne particles can be trapped by moisture. Build-up of this debris can be carried off as condensate drains from the coil. Over time, it can become trapped in your condensate drain line, causing blockage.
What to do after drain is cleaned and tested?
Once the drain has been cleaned and tested, your technician will reassemble or reinstall any parts removed, restore power to the system and check to be sure everything is functioning properly.
Can AC shut down?
AC system is not cooling your home. AC system shuts down or doesn’t turn on. If you experience any of the above situations, it’s probably time to contact an HVAC professional who knows how to clear a clogged air conditioner drain line.
Can AC condensate drains be blocked?
Over time, it can become trapped in your condensate drain line, causing blockage. As a preventative measure, many HVAC technicians will inspect and clear debris from the AC condensate drain during your annual maintenance tune-up. If this service isn’t done regularly, you could potentially experience a clogging issue.
Common solutions for: Carrier Air conditioner fan not working
The dual shaft fan motor (or circulation fan motor) might be defective. The circulation fan motor has two fan blades: one on either side of the motor. On one side, the fan blade draws in outside air over the condensing coil to dissipate the heat. On the other side, the fan blade directs the air over the evaporator coil.
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What are the problems with air conditioners?
The Most Basic Problems of Air Conditioners. With residential air conditioners, there are a lot of moving parts. There are electrical and mechanical components, refrigerants, and a lot of copper tubing. Something can go wrong at any time.
Why does my air conditioner fail?
The other most common issues with automotive air conditioner failure are due to leaks in the refrigerant lines, bad seals, or a worn compressor clutch. All of these issues require a trained and licensed professional to diagnose, locate (for leaks), and repair.
Why does my Lennox air conditioner lose airflow?
After installing a Lennox air conditioner, the biggest consumer complaint is that the system loses airflow. However, this generally goes beyond a dirty or clogged air filter (though you should always check this first). The largest reason this occurs is that the system is improperly installed.
Is an air conditioner the same as a car?
Almost all automotive air conditioners are the same. What is different, though, is the car around the system. Knowledge of the car brand and make is important, and you should ensure that the mechanic knows the brand well enough to work on your car.
Can a leaking evaporator cause water to leak?
Indoor water leaking is almost always found around the evaporator unit. When the air passes over the evaporator coils, it condenses. The condensate falls into the drain pan where it is removed from the home through the drain line. If the drain line or pan is clogged, though, it can overflow, causing a water leak.
Is it normal to see condensation on a refrigerant line?
However, it shouldn’t be so bad as to create puddles or small streams of running water.
Can refrigerant leak in a sealed system?
As a sealed system, refrigerant should never leak. There is nowhere for the refrigerant to exit the system by design. This means that if you have low refrigerant, there is a leak somewhere. When there is low refrigerant, the system will stop blowing cold air.
How often should I replace my AC contactor?
Even if your AC contactor is working, it pays to replace it every five years or so. Unscrew the old AC contactor before removing the wires. Then move the wires to the new unit ( Photo 6 ).
What to do if compressor doesn't start?
If the compressor starts but the fan doesn't, the fan motor is most likely shot. Shut off the power and remove the screws around the condenser cover. Lift the cover and remove the fan blade and motor. Reinstall the blade and secure the cover. Then repower the unit and see if the fan starts.
What is the A coil on a central air conditioner?
Central home air conditioner service systems consist of two major components: a condensing unit that sits outside your house, and the evaporator coil (often referred to as an A-coil) that sits in the plenum of your furnace or air handler. The refrigerant in the A-coil picks up the heat from your home and moves it to the outdoor condensing unit. The condensing unit fan blows outside air through the condensing coil to remove the heat. The condensing unit houses the three parts replaceable by a DIYer: the AC contactor, the start/run capacitor (s) and the condenser fan motor. The condensing unit also houses the compressor, but only a pro can replace that. The A-coil has no parts that can be serviced by a DIYer.
What does a blown fuse on a condensing unit mean?
Many disconnect blocks contain two cartridge fuses. Check them before you proceed with repairs. A blown fuse is a sign of a failing part inside the condensing unit. So don't just replace it and think you've solved the problem. Instead, replace the parts, install new fuses, and fire up the unit. If it blows again, call a pro—you've got more serious issues.
How long does it take for an AC unit to reset?
AC units and thermostats have built-in delay features when they're shut down and then repowered. The delay can be as long as 10 minutes. And, if you've subscribed to an energy-saving device from your local power utility, the unit can take even longer to reset. If you've installed the parts shown and reinstalled the disconnect block, repowered the circuit breaker, turned on the switch at the furnace, moved the thermostat to AC mode and lowered the temperature below the indoor temperature, and the unit doesn't fire up after 30 minutes, it's time to call a pro.
Do AC units have capacitors?
All air conditioning service units have at least one capacitor. The capacitor stores electricity and releases it during compressor and condenser fan startup to give both motors an extra jolt of power. And it smooths out voltage fluctuations to protect the compressor and condenser fan motor from damage.
Can capacitors degrade over time?
Capacitors can degrade slowly, providing less startup power over time. Or they can fail in an instant. Gradual capacitor failure can go unnoticed for a long time, stressing the compressor and condenser fan motor windings, resulting in their early failure.
