2 system full system maintenance. Inspected heating elements. Cleaned flame sensors. Replaced downstairs air filter. Upstairs filter was clean. Checked inducer motor amps. Checked heat exchangers. Checked temperature differentials. Inspected duct work and drain lines. Checked cooling elements. Checked condensing unit. Checked electrical components. Coils are clean. No issues found at this time. Systems are working as designed. Recommend adding float switches to both systems. Customer will call back at a later date to set up appointment.