I just started working at a fancy high end retirement village and each apartment is equipped with one or more Amana Ptac heat pumps. They work well but I am not real familiar with the charging procedures. I keep several new units in stock for emergency replacement as the old folks have health issues when it is very hot here in NC. I now have several units in my shop with more problems than the typical control boards, which seem to be a problem from the word go. If i need to check pressures should I install a quick tap and evacuate then solder in a high and low permanent tap or just leave the temp tap in place. Also where can I get some tech info on these units. The new units don't even come with T/P charts. They do have scroll compressors.