Upon arrival technician found that the primary drain line was clogged and the system was leaking into the secondary pan, the technician recommended blowing out the primary drain line and installing an SS 1 float switch. The customer but worth blowing out the primary drain line and holding off on the plug switch for now. The technician brought the primary drain line and installed a vent for the customer to pour White vinegar in the drain line to neutralize the growing algae.