The purpose of this post is to provide UPDATED service guidance to address erratic thermal expansion valve performance which results in observed high superheat conditions, at times coincidental with compressor failure.
Reports of failures of this type have been industry wide in recent weeks. Instances of this failure mode have been very isolated , but when experienced, proper practices must be followed to accurately diagnose the problem and restore system performance. (See posts on TXV diagnostics)
These problems have been observed across both residential and commercial equipment. Suppliers and other industry experts are actively engaged to identify and confirm root cause and corrective action.
In conjunction with compressor suppliers, many manufacturers have confirmed and are authorizing the use of the following chemical additive to restore system performance. This additive effectively dissolves the contaminant debris on the TXV components and restores system operating performance. Use of the additive offers a more cost and time effective approach, in lieu of opening the system, replacing driers and replacing the TXV.
You do need to check with your specific manufacturer as to how they are going to approach the “restricted” txv issue.
I have attached Nu-Calgon’s instructions for use of the additive. As additional information is released concerning long-term reliability assessment and proactive field actions, I will try to keep you up to date on that information.