Arrived to remedy an inoperable air conditioning system. Upon inspection of the system, found it running like normal. Performed diagnostic and found the system to b operating properly but assumed it wasn’t able to keep up in the weather. Set the fan speed one speed lower. Tested system operations and found that the furnace would turn off and would only relight after about 10 minutes. Reset the fan speed. Performed further diagnostic and found that the condensation system had a blockage. Blew through the drain and cleared the blockage. Checked the outside portion of the drain and found ice. Recommended installing heat tap on the condensation drain. System is operating properly upon departure.