If your current heat pump needs a new compressor, record the make and model of your heat pump and contact a dealer.  Below are links to the most common dealers in your area: Carrier heat pump dealer (enter zip code in upper right hand corner of the page)American Standard heat pump dealer Pros of a new, equivalent compressor:No risk associated with using a different compressorThe warranty of the entire heat pump may stay in place (as long as the other conditions are adhered to)Cons of a new, equivalent compressor:Pros of an off-brand/refurbished compressor:Cons of an off-brand/refurbished compressor:May be louderMay results in a less efficient heat pumpThe heat pump may need additional "tweaking" for smooth operationIn conclusion, it is worth checking out the price of both an equivalent model and an off-brand model.  If the price difference is minor.....go with the equivalent model.  While most off-brand compressors do just fine, some do not.  As a result some homeowners have had to spend more money in the end because the heat pump compressor failed more quickly.

A compressor performs two functions within the refrigeration cycle:Maintains a specific rate of refrigerant flowIncreases the pressure of the refrigerant by "compressing" the refrigerant gasWhen problems with the compressor exist, one or both of the above functions are affected.Is there a difference between a compressor in a heat pump versus a standard air conditioner?In fact, a compressor used in an air conditioner can be equally exchanged with the compressor in a heat pump (as long as the heat pump compressor performance for the cooling side of each is the same, as well as other criteria such as pressure differential and refrigerant type).Most modern heat pumps utilize a scroll compressor, as this is typically the  quietest, most efficient compressor for residential and small commercial applications.Below is a fantastic video from Copeland, one of the largest scroll compressor manufacturers in the world. It doesn't have any sound explaining the process, but it is somewhat intuitive.  

Just note for the video: the blue gas is the low temperature/low pressure refrigerant entering the compressor and the red gas is the high pressure/high temperature refrigerant leaving the compressor. There are many, many different noise that come from a heat pump compressor which can help to diagnose problems.First let's hear how a good compressor sounds.  You will hear slight fluctuations in noise as the compressor loads and unloads. Next this is a good example of a compressor that is going bad, but still operating.Scroll compressor going bad: When a compressor shuts down, internal equalization can cause the compressor to "backspin" if the check valves are non-existent or not working correctly.  Below is an example of what this sounds like.Scroll compressor backspin at shutdown: To replace, or to not replace. That is the question.The answer to this question is actually somewhat simple.  Assuming that the technician has made an accurate diagnosis.....We must determine whether or not the unit is too old to justify a brand new heat pump compressor.

Due to high labor costs many people ask this question.  Here are a few things to consider:EPA regulations state that it is illegal to service or repair refrigeration machinery without the certification required to handle refrigerants.  If the refrigerant in the heat pump is bad, the new compressor will quickly go bad as well.  air conditioning unit tax credit 2013Trained professionals always test the refrigerant for acid to ensure this will not happen.how to move hvac unitMost older heat pumps contain R-22 which is an ozone depleting refrigerant.  ac unit not getting 24 voltsMost newer heat pumps contain a more environmentally friendly R-410a.  You must ensure that you purchase and install all components that are designed to work with the correct refrigerant.