Below are system manuals for HVAC and water heater units as well as links to helpful maintenance info and trade referrals.

LENNOX HVAC MANUALS:
Lennox_XC21(Ver.04-current)
Lennox_XP16_Manual

NAVIEN WATER HEATER MANUAL:
Navien-Owners-Manual

LINKS TO MAINTENANCE INFO/CALENDARS:
-Embed Maintenance Reminders in Your Google Calendar: Click Here
-General Maintenance Advice (By System): Click Here
-General Home Maintenance Manual/Check List: Click Here
-Life Expectancy of Home Systems: Click Here

MAINTENANCE LIST:
For a bullet list of maintenance recommendations CLICK HERE

REFERRAL INFO:
Trade referrals can be viewed HERE