Arrived on site for heating maintenance. Found 33a (left air handeler) thermostat not power on. Tested for 24v volts from common to R and found nothing. Upon further inspection I found a bad fuse. Reviewed and tightened all wire connections and did not find further issues. Replaced 3 amp fuse with a 5 amp fuse and unit powered on and continued to work without issue. Tested electric strip heat on both units and found they were testing within manufacturer specifications. Tested blower amps and replaced filters. Inspected evaporator coil. Noticed decent amount of dust buildup on blower wheels. Outdoor coils are clean. Units heating well upon departure.
