Why is my AC making a hissing noise?

July 25, 2019

A hissing noise inside your HVAC system should not be ignored. Among the possible causes are leaking5 refrigerant lines, an internal valve leak or a serious failure with your compressor. If the hissing noise is heard from your ducts, then you may have leaky air ducts. This is annoying, but not necessarily a cause for alarm. A hissing sound could be a sign for any of these things, but we’ll try to narrow it down further.

Does the hissing sound stop after a few seconds?

If you hear a hissing noise that ceases after a few seconds, you may not have any problems. That can be refrigerant in your expansion valve, which is part of the normal operation of your HVAC unit.

Is the AC Making a Hissing Sound with Bubbling Noises?

Are you hearing a bubbling sound paired with a hissing sound? This may indicate a refrigerant leak. If a refrigerant leak is present, you may notice a slight hissing sound as the refrigerant escapes from the leak. It escapes as a gas and can be a worrisome health concern. If you notice signs of a refrigerant leak, turn off your HVAC and call a expert HVAC company to come inspect the system.

If the cause is a valve leak, it should be repaired by a technician as soon as possible. The job of the valves is to help with the pressurization of the refrigerant gas and if unresolved, the leak will worsen. When it does, the hissing sound will increase, which can be a signal if you’re looking for the cause. You must maintain proper pressure in your system for it operate correctly, and refrigerant leaks cause additional health and maintenance problems. It’s best to get this fixed quickly if possible.

Are Hissing Noises Coming from the Compressor?

The compressor can be found in the exterior air conditioning unit, which is also known as a condenser unit. Listen around here for the hissing noise. If the compressor is the problem, this could be a dangerous situation because it is a sign that the pressure in the compressor is too great. If you hear hissing, whistling, or shrieking coming from your compressor, shut off your air conditioner without delay and call an expert technician.

AC compressor located in exterior condenser unit 

Compressors are some of the most costly parts to repair or replace inside an AC. Compressors are the part responsible for cycling refrigerant through the system. You cannot run an AC and cool your home without a compressor. The expense is variable based on factors like the type, unit size, and brand requirements. If you have a two stage compressor now, you will need to replace it with a two stage compressor. It’s impossible to upgrade or downgrade the compressor type - your unit has specific requirements for what components are installed and can’t be MacGyvered. While it’s impossible to provide estimates because of the variable costs, the bill is frequently big enough to think about a replacement in older air conditioners. This is why it’s crucial to shut off the air conditioning and call a reputable HVAC company if you hear hissing sounds coming from the compressor.

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