Preformed 3 system heating maintenance 2014 gas. Tested all electrical components and safeties on each of the units. All tested within manufacturer specifications. We changed all filters 20x25x4(2) and 16x25x4. We did find that the master bedroom blower wheel could benefit from a good cleaning, also found on the upstairs unit and down stairs unit that both could benefit from a duct and plenum box cleaning. Units were cooling upon departure.