I completed a three system maintenance. I replaced the media filter on the dehumidifier and the 16x20x5 for the basement system. Customer has the 20x25x5 media filters arriving today for the main floor and upstair. I checked amp draw on blower motors,inducer motors and heat strip. I cleaned flame sensors and checked igniters. I checked temperature rise and checked safeties. I confirmed proper sequence of operation. Units are currently heating at manufacturers specifications.