We recommend that Raleigh homeowners do yearly tune ups for their heat and air systems to prevent costly repairs. HVAC maintenance service includes checking the compressor capacitor because they loose conductivity, We check to see if the thermostat energizes the out door fan motor properly. Then we service Freon and clean coils to make sure your HVAC meets the energy star rating. Raleigh, Durham and Chapel Hill have a lot of homes with heat pumps that get clogged drain lines and this areas muddy clay gets the AC coils dirty. The compressors work harder when the filter is dirty and the air conditioner capacitor is weak so we check them too.