Why is my AC making a hissing noise?

July 25, 2019

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

Does the hissing sound end after a few seconds?

If you hear a hissing noise that stops after a few moments, you may not have any issues. That could be refrigerant in your expansion valve, which is part of the normal day to day operation of your HVAC mechanicals.

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 develops, you might hear a light hissing sound as the refrigerant escapes through the leak. The coolant escapes as a gas and can be a worrisome health concern. If you have signs of a refrigerant leak, power down the unit and call a expert HVAC company to come inspect the system.

If the issue is a valve leak, it should be repaired by a qualified technician as soon as possible. The job of the valves is to manage the pressurization of the refrigerant gas and left alone, the leak will worsen. When it does, the hissing sound will increase, which can be a sign if you’re looking for a cause. You need to maintain adequate pressure in your HVAC system for it run as intended, and any leak will create additional health and mechanical problems. You ought to get this fixed post haste if possible.

Are Hissing Noises Coming from the Compressor?

The compressor is found in the exterior air conditioning unit, which is also known as a condenser. Listen nearby the condenser for the hissing noise. If you find the compressor is the problem, this could be an unsafe situation because it is an indication that the pressure in the compressor is too high. If you hear hissing, whistling, or shrieking coming from your compressor, switch off your air conditioner immediately and call an expert technician.

AC compressor located in exterior condenser unit 

Compressors are some of the most pricey units to repair or replace inside an air conditioner. Compressors are the part responsible for circulating refrigerant through the system. You cannot turn on an air conditioner and cool your home sans compressor. The expense is variable based on factors such as the type, unit size, and brand requirements. If you have a two stage compressor in your AC, you would need to replace it with another two stage compressor. It’s not possible to upgrade or downgrade the compressor type - your unit has specific requirements for what components are installed in order to operate safely. While it’s impossible to give a quote online because of the variable costs, the receipt is frequently big enough to consider 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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