Performed semiannual maintenance on one heat pump cooling system. Inspected all Performance, Mechanical and Safety Systems. Homeowner mentioned that the water safety switch coming off the internal drain pan would sometimes get water inside it, so he would tilt it upwards to help keep the system running. During my inspection, I found that the internal drain pan had some standing water inside due to there being gunk that had formed near and around the drain ports. Cleaned and cleared the primary drain line and the internal drain pan. Also added drain treatment into the pan and line, along with installing a union between the p-trap and the air handler to allow for cleaning of the line coming out of the air handler. Verified all other mechanical components were operating within manufacture’s specifications for operation. Everything is working at this time.