Arrived on site to diagnose a blank thermostat on a new system install. Found thermostat blank. Spoke over with clients on what happened. They stated just went blank 2 hours later after install. Went and inspected indoor Equipment and drain lines. Found safety float switch is tripped causing thermostat is blank. Found drain line dirty. Primary drain line is clogged. Under skin is clogged. As well P-traps where dirty as well. Vacuumed all drain lines. Used nitrogen to clear lines as well at T coupling. Over all eliminated system having a clogged line. Cycled system to test drainage. Found due to the way installers routed drain line there is no down flow of water allowing it to drain properly. Advised the office as well as clients of issues now and will have install come back out and rout drain line right. Client did want to go forward with adding a safety float switch and replace P-trap with upstairs unit. Units were operational but advised to client to not use downstairs system to pr