Performed AC diagnostic on Lennox system. Upon my diagnostic client stated that system has been draining out of the secondary drain line on the side of the house and are concerned about it. Proceeded to attic to find a primary drain line is backed up and it’s causing it to pool in the secondary drain pan under the evaporator coil. Performed condensate P-trap clean out under sink in bathroom and cut and clear up in the attic we’re all debris was vacuumed out along with water in secondary pan. Primed drain line and system was draining properly upon departure. If secondary continues the drain this could be due A crack evaporator coil primary pan.