Why is my AC making a hissing noise?

July 25, 2019

A hissing noise inside your HVAC system should not be disregarded. Among the possible causes are leaking5 refrigerant lines, an internal valve leak or a serious issue with your compressor. If the hissing noise is originating from your ducts, then you could have leaking air ducts. This is annoying, but not necessarily a reason to worry. A hissing sound may indicate any of these things, but we’ll try to narrow it down a little more.

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 day to day operation of your HVAC system.

Is the AC Making a Hissing Sound with Bubbling Noises?

Are you hearing a bubbling sound along with a hissing sound? This could indicate a refrigerant leak. If a refrigerant leak presents itself, you might notice a light hissing sound as the refrigerant escapes through the leak. Refrigerant escapes as a gas and can be a serious health concern. If you notice signs of a refrigerant leak, power down your HVAC and call a qualified HVAC company to come evaluate the noise.

If the cause is a valve leak, it should be repaired by a professional 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 tell if you’re looking for the cause. You must maintain proper pressure in your system for it run as intended, and refrigerant leaks cause additional health and maintenance problems. You ought 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 called a condenser. Listen around here for the hissing noise. If you find the compressor is the cause, this could be an unsafe 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 unit. Compressors are the part responsible for cycling refrigerant through the system. You cannot power on an HVAC system and cool your home without a compressor. The pricing is variable based on factors like the type, unit size, and brand requirements. If you have a two stage compressor in the unit today, you will need to replace it with another two stage compressor. It’s impossible to upgrade or downgrade the compressor type - your unit has specific requirements for what parts are installed and won’t accept substitutes. While it’s impossible to give a quote online because of the variable costs, the receipt is frequently big enough to think about a replacement in older units. This is why it’s crucial to shut off the air conditioning and call a reliable HVAC company if you hear hissing sounds coming from the compressor.

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