I have a three ton heat pump split unit which is about20years old and just went out. I plan to install a new unit with R 410A. Can I use the existing tubing. What would be the correct method to evacuate the tubing. Thanks in advance for any comments. Archie,
Summerville, SC

I have a three ton heat pump split unit which is about20years old and just went out. I plan to install a new unit with R 410A. Can I use the existing tubing. What would be the correct method to evacuate the tubing. Thanks in advance for any comments. Archie,
Summerville, SC

Use new tubing of the proper size for your new system. The old tubing would have to be professionally cleaned with a pressurized solvent and when it is all said and done the cost is about the same since the cleaner is expensive.

You actually need an EPA license to work on or service the refrigerant in the system. The proper evacuation method is just standard stuff that all HVAC service people will know.

Nothing wrong with you doing the install but have a licensed service person do the line set brazing and the evacuation and charging.