REFRIGERANTS: When you get a leak from a system containing a blend do you have to remove the remaining product and charge with virgin product?

Although there may be occasions with some refrigerants where this may be necessary, in the vast majority of cases, it is possible to top up with virgin product and return the product to specification. If the performance of the refrigerant is worse than expected, then it may be necessary to replace the charge.

Our experience with a number of blends including the ISCEON 9 series has shown that up to 80% can be lost before the composition changes significantly.  There is documentary evidence on producer websites that suggest you can top up refrigerants including R-407C, without any significant loss of performance.