You walk inside on a blazing summer day, expecting a wave of cool air to hit you. Instead, you get nothing. You put your hand up to the vent and feel lukewarm, stagnant air. The worst part is that you can hear your air conditioning system running, but your house just keeps getting hotter. It’s a baffling and incredibly annoying problem.
There are a handful of common reasons for this kind of AC behavior, and we know a few tricks to solve them.
Check the Air Filter First
This is the most common reason for an AC running but not cooling, and luckily, it’s the easiest to check. Your air conditioner works by pulling warm air from your home, cooling it, and sending it back out. To do this, the air has to pass through a filter. If that filter is clogged with dust, pet hair, and other gunk, your system can’t breathe. The airflow gets choked off, and not enough air can pass over the cooling coils. The system will run and run, but it can’t circulate enough cool air to make a difference.
The Outside Unit Might Be Obstructed
Your AC system is a team. The inside part absorbs the heat, and the outside part (the condenser) is responsible for releasing that heat into the atmosphere. For it to do its job, it needs plenty of room to breathe.
Take a walk outside and look at your condenser unit. Is it crowded by overgrown bushes? Are the sides covered in grass clippings, dirt, or drifting cottonwood fluff? Anything that blocks the fins on the unit prevents it from getting rid of heat effectively. That forces the system to work harder for zero results, giving you an AC that’s running but not cooling.
You Could Have a Refrigerant Issue
Refrigerant is the substance that flows through your AC’s coils, absorbing heat from your indoor air. A lot of people think it gets “used up” like gasoline in a car, but it doesn’t. Your air conditioner features a closed-loop system, which means the refrigerant is designed to last the life of the unit. If your system is low on refrigerant, it almost always means there’s a leak somewhere. You might notice ice forming on the copper lines near your indoor or outdoor unit, or you might even hear a faint hissing sound. This is a job for a professional, as handling refrigerant requires a certification.
The Evaporator Coils May Be Frozen
It sounds strange, but a block of ice inside your air conditioner is a bad sign for cooling. The indoor evaporator coils are what the refrigerant flows through to absorb the heat. When airflow is weak (like from a dirty filter) or refrigerant levels are low, these coils can get so cold that condensation on them freezes solid.
A frozen coil completely blocks airflow, so even though the system is running, no cool air can reach your vents. If you suspect this is the problem, you can turn your system off and switch the fan to “on” to help it thaw. However, this won’t fix the underlying cause of the freezing.
Is Your System the Right Size?
An air conditioner needs to be properly sized for your home. If a system is too small, it will run constantly on hot days but will never be powerful enough to actually reach the temperature you set on the thermostat. On the other hand, a system that’s too large might seem like a good thing, but it causes problems, too. It will cool the house down so quickly that it shuts off before it has a chance to remove humidity from the air, leaving your home feeling cool but damp and clammy.
Thinking Outside the AC Box
Sometimes, the air conditioner itself is working just fine, but other things are getting in the way of a cool home. Your house works as a whole system to keep you comfortable, and a weak link can make your AC’s job impossible.
- Poor Insulation: If your attic insulation is thin or old, heat from the sun will just pour into your house from above. Your AC might be producing cool air, but it can’t compete with the constant heat gain.
- Leaky Ducts: Your ductwork is the delivery system for cold air. If there are holes or gaps in the ducts, all that precious cool air is leaking into your attic or crawlspace instead of coming out of your vents.
- Thermostat Glitches: Your thermostat is the brain of the operation. If it’s malfunctioning or even just has dead batteries, it might not be telling your AC to cool properly, even if the system itself is running.
Getting Your Cool Air Back
When simple fixes like a new air filter don’t solve the problem, it’s usually a sign of a deeper issue that needs an expert eye. Problems like refrigerant leaks, frozen coils, and electrical glitches are best left to a trained HVAC technician to keep you safe and prevent more costly damage to your system.
The team at Andreas Plumbing is here to figure out what’s going wrong. We offer complete AC repair services to diagnose and fix whatever is keeping your home from cooling down. To prevent these problems before they occur, we also offer AC maintenance that keeps your system in optimal condition for the summer heat. Give us a call today to schedule your appointment in the Lehigh Valley!