Something’s wrong with your central air system. You’re pretty sure it’s low on refrigerant, but how can you be sure before you call in the experts to fix it?

Air conditioning units are fairly straightforward machines that serve one function: keeping you and your family cool and comfortable when temperatures outside are high. However, the inner workings of an AC unit are something not most people are familiar with, which is why you call Hey Neighbor Heating & Cooling to do the job. We understand, so here are some of the most common indications that you have a low refrigerant problem with your air conditioner.

Your system is blowing hot air

To cool the air throughout your home, your air conditioner needs the proper amount of refrigerant. Too little refrigerant can cause your system to blow room-temperature or even warm air. Of course, other things might cause this problem as well – a dirty outside unit, setting your thermostat’s fan setting to ON instead of AUTO, or issues with the compressor itself. With those potential issues in mind, look for these other signs.

The refrigerant line is iced over

You might know that spraying a can of compressed air for a long time makes the can feel very cold. This is because the low pressure in the can quickly lowers its temperature.

Something similar happens when your air conditioner runs low on refrigerant. Low refrigerant causes low pressure, and low pressure causes low temperatures, which will eventually freeze the system’s evaporator coil. When the coil freezes, cold liquid refrigerant flows through the refrigerant line, causing the moisture in the surrounding air to condense onto it and freeze.

You hear a bubbling or hissing sound

Refrigerant lines are highly pressurized, so if there’s a significant refrigerant leak, you’ll hear a hissing or bubbling noise – somewhat like when squeezing a balloon with a hole in it.

By the way, a leak is more or less the only reason why your system would be low on refrigerant. You see, refrigerant isn’t consumed like a car uses gasoline. A properly-filled air conditioning system should stay that way for a long time, barring a leak.

Your compressor stops

The compressor is the heart of your central air system. Its job is to compress refrigerant vapor into liquid and pump it through the system, cooling the surrounding air. The compressor has a pressure cut-off switch, which protects it operating at low refrigerant levels by turning the unit off when its refrigerant pressure falls below a set value. The compressor will then start again once refrigerant pressure is restored.

When forced to run with low refrigerant pressure or without refrigerant entirely, a compressor can become very hot. If the compressor is damaged due to overheating, it will no longer reset and will need to be replaced. On some models, internal safeguards may exist to protect the compressor, even if the cut-off switch fails or has been bypassed.

Thermostat stops the compressor prematurely

It’s the thermostat’s job to start and stop the compressor, but only when the selected temperature level is reached. However, high heat loads will result if the thermostat stops the compressor prematurely. A compressor that is stopped before it can lower the temperature to the set level is probably lacking refrigerant.

Short compressor run times

Very low refrigerant levels often result in noticeably short compressor running times. This symptom also tends to present itself with unusual noises coming from the compressor and a loss of cooling.

A low refrigerant level in your AC system isn’t a problem you should try to fix yourself. Equipment damage and possibly serious injury can result. Instead, trust our well-trained HVAC experts to come to your home, determine the issue, repair it, and recharge your refrigerant to the correct level. Once we’ve taken care of the problem, your AC system will be back to its optimal cooling capacity, providing you with the level of comfort you desire.

OK, your AC lacks refrigerant – what to do now?

By law, a technician cannot “top off” a system with more refrigerant if they know there’s a leak. Even if someone did add more refrigerant, you’d regret it in short order because the leak allows the refrigerant to escape again (and that stuff is very expensive). Also, a leaking AC unit will work inefficiently and eventually become damaged.

What we recommend: Call us immediately to find the leak and fix it – only after we’ve done that will we add more refrigerant. Your family will be cool and comfortable before you know it! That’s how neighbors should treat neighbors!™