Tech arrived at a warranty tuneup. Upon inspection, the capacitor out of tolerance and was replaced. There was no observed surge protection. The filter was relatively clean. The blower area was a little dirty. The UV system was functioning. The drain was clear and bleach was poured. There was no inline float switch. There was corrosion present on the water heater. This is a solar water heater. The customer was informed of recommendations today. He decided to move forward with upgrading the 20*20*5 box filter to a AprilAire filter. This part will be ordered. He would also like to set up an appointment next week for a plumber to evaluate the water heater. The system was functioning upon departure.