Water heater & Furnace tips:
Check all around your hot water tank (including top & bottom). Look for water sediments. Water sediment takes time to form. If you find sediments on your tank, it was likely caused by a constant leak.
Look for wet spots or rust all around your hot water tank. You won’t always find water sediments. Instead, you might find rust or small puddles. If you find water at the bottom of your water heater (after removing the little door on the bottom), your water heater might be cracked! Rusts, puddles, white dust (at the bottom) are never a good sign!
Look for the install date of your hot water tank. These days, hot water tanks average a 12 year life span. If your water tank was installed 20-25 years ago, it would be recommended to replace it!
Not getting enough hot water? It might be something simple. Example: A tube in your tank has broken off. Your water heater could also be filled with water sediments that has accumulated over time
Is your water heater still under warranty?
http://www.bradfordwhite.com/check-your-warranty
http://www.rheem.com/warranty/verify
Maintenance records are required for warranty purposes (if you own a tankless water heater). Tankless water heaters require a minimum of 1x per year heat exchanger flushing
Are there any obstructions in any of your vents or intakes?
It is recommended to drain your hot water tank once per year