Tech arrived at a membership service call. The customer mentioned that she was having thermostat problems. The thermostat was not functioning at this time. The customer recently replaced the batteries and they were in backwards. After repositioning, the thermostat began functioning. The drain system was checked and was found to be clogged. The trap was disassembled at the sink. Everything from the sink trap up was cleared. The trap was fastened and there were no leaks observed. The sink was tested and was draining slowly. Chemical was introduced and helped the flow. The customer was informed that if this happens again, a plumber should be called as the AC plumbing should be clear. A treatment strip was added to help keep the drain system clean. The system was functioning upon departure.