Why is Your AC Blowing Warm Air?
Your air conditioner could be blowing warm air for a variety of reasons. Sometimes it is a simple DIY fix, but most of the time, it requires in-depth technical troubleshooting and advanced repair.
Since most of these troubleshooting tips and repairs require technical skills and experience, we would suggest giving our HVAC experts a call if you’re a complete novice with HVAC repairs.
Our pros can easily diagnose the issues and repair them in no time since they have the knowledge, experience, and tools to get the job done.
With that said, here are the most common causes why AC units blow hot air and what can be done to fix them.
Thermostat Setting is Incorrect
Before you start worrying that your air conditioning system has a severe issue, check your thermostat setting. The most common reason AC units provide heat is that the furnace is actually turned on.
Even though this is a “common sense” type of issue, there’s still plenty of people overlooking this. So make sure you double-check your thermostat.
Most often, it happens because a homeowner’s family member changed the setting to heat without anyone knowing.
A covert switch to heating mode has left many homeowners scratching their heads as to why their air vents are blowing heat when they think the thermostat is set in “cool mode.”
The act of switching your thermostat back to cooling is a simple fix to this problem and pump cold air into your home!
Refrigerant Leak or Low Refrigerant
If your air conditioner’s refrigerant levels are low, this can be the culprit that is causing your air conditioning system to provide warm air.
AC units use the vapor-compression refrigeration cycle to cool air. A necessary component of this cycle is the liquid and gaseous refrigerant that fils the coils of the condenser and evaporator, which are connected by refrigerant lines.
The refrigerant is expanded and contracted through a thermal expansion valve as air is blown across the evaporator coils to remove heat (and cool the air). Over time, the refrigerant could slowly leak out of microscopic holes and need to be replenished.
Very low levels of refrigerant in your coils can prevent the air conditioner from removing heat properly and would therefore provide warm air instead of cool air into your home.
Besides refrigerant just naturally decreasing over time, it can get lost through a leak as well. Leaks in the evaporator or condenser coils can eventually deplete the refrigerant in the system leading to only warm air coming into your home.
Recharging refrigerant can only be accomplished by certified professionals as mandated by the Clean Air Act.
Refrigerant is harmful to the ozone, so the EPA has made guidelines and technician certification programs to ensure it is done correctly.
Our HVAC technicians have passed an EPA-approved exam to achieve Section 608 Technician Certification. With this certification, our pros can inspect, repair leaks, and recharge your refrigerant. Give us a call today if you suspect you have a refrigerant leak!
Circuit Breaker Issues
One reason your AC system may be providing warm air into your home are issues with a circuit breaker tripping. For example, if the circuit (in your breaker box) connected to your air conditioner switches off, the fan may stay on and continue to circulate air.
If the air conditioner is not cooling the air, it will feel warm, especially if it is warm outside.
The circuit may be tripped because too much power is being pulled by the AC unit. Too much power being pulled could be a more significant electrical issue with the AC unit or simply because too many devices attempt to draw power from the same circuit and are overloading it.
Sometimes, there are no discernable reasons why the circuit breaker trips and turns off, which can be fixed by simply flipping the breaker back on. However, it is almost always an electrical issue that needs to be seen by a professional. Please give our HVAC experts a call so we can help!
Failed Relay or Capacitor
The majority of central air conditioning systems are designed in a similar fashion. On the outside unit (or condenser), there is usually a relay along with a capacitor to control the fan and provide adequate power to it.
The relay switches the condenser (and its fan) on and off, while the capacitor switches single-phase power to poly-phase power to control the motor.
A failed relay won’t try to switch on the condenser at all, and the fan will remain still. If you have a blown capacitor, it may look like the fan is trying to move but fails. A blown capacitor usually has a bulge on the top or bottom, whereas working ones are flat and mouth.
If either the relay or capacitor on the condenser breaks, they will need to be replaced with components meeting the exact specifications. There’s no bypassing them.
If you’re attempting to replace these components yourself, make sure the power is completely off and that you connect everything correctly – consult the AC unit’s user manual for detailed instructions.
You’ll have to remove a panel on the condenser unit and do some tricky rewiring.
If electrical work sounds like you’re in over your head, that’s not a problem! Pick up the phone and give our HVAC experts a call for assistance! We’ll likely have the replacement components in stock and will be able to get you up, running, and feeling cool in no time.
Dirty Condenser
A very dirty condenser can be a reason why your air conditioner is providing hot air. The condenser is also known as the outdoor unit, which sits outside your home. If it is clogged with leaves, branches, grass, and dust, it can inhibit its proper function and lead directly to the hot air problem.
To clean a dirty outdoor AC unit, you should turn the power off first. Then you can remove the top part with the fan by undoing a few screws.
After the top part is off, you can scoop out the buildup of any twigs, leaves, grass clippings, and other dirt that has become trapped in there.
Additionally, you can spray out the inside with a garden hose to get additional dirt off the coils and fins.
Dirty Filter and Evaporator
One of the more common reasons for air conditioners blowing hot air is because the filter is badly clogged. In other words, it is so dirty that the dust and grime usually collected by the filter is caked onto the evaporator coils too.
If this has happened to your air filter and evaporator coils, then it could almost entirely block the airflow, which could make the tiny amount of air coming out of your registers feel warm.
To fix these issues, clean your dirty air filter or replace it. When you remove the dirty filter, check the evaporator coils for a buildup of dust. Vacuum the dirty evaporator coils with a soft bristle brush vacuum attachment if you notice grime caked on it.
Air Conditioning Maintenance
Routinely doing maintenance to your AC system could prevent warm air issues from ever occurring. As a homeowner, there are a few things you can do to keep your air conditioner running smoothly, including:
- Checking the air filter every 30 days
- Replacing the air filter every 4-6 months
- Removing debris (leaves, grass clippings, etc.) from around your outdoor unit
- Cutting back vegetation up to 3 feet away from the condenser
- Scheduling routine AC maintenance and tune-ups with an HVAC technician
When Should You Hire An HVAC Professional To Fix Your AC Unit Blowing Hot Air?
If your air conditioning system is providing hot air into your home and despite your troubleshooting, you can’t get cold air- give our HVAC experts a call. We can schedule a visit and get you taken care of right away.
Our HVAC technicians are certified to find and repair leaks and recharge the refrigerant in your system. They have years of experience in air conditioning repair, will do the job right, and for a fair rate while making your home’s air cool.
