Installed flared reducer fitting with gasket and connected refrigerant lines. Utilized torque wrench and secured to appropriate ft-lb as indicated in installation manual. Pressure tested system, found a previously unknown leak on lineset connection. Secured to appropriate ft-lb as indicated in installation manual. Pressure tested system again, this time with R410 added to the nitrogen, to 400 psi. Conducted another leak search with refrigerant detector, none found. Pressure test held at 400 psi for 10 minutes Conducted vacuum, pulled system down to 498 microns Added 6lbs, 2 oz of R410 refrigerant and tested systems. All 3 heads have a 20+ degree temperature rise in heating Note : all blower wheels had been cleaned previously during the call where we identified the improper use of gas fittings