Water in shower is hot for only 10 minutes then goes to warm then cool.

[teddogz]

I live in a 36 year old 1350 sq foot home. My water heater is a natural gas type. 40 gallon Sears Power Miser 5. I would approximate that the water heater is at least 22 years old. If one of us takes a shower. The hot water only last about 5 to 10 minutes, then goes from warm to cool. (my wife never runs the washing machine or dishwasher before we take showers) Coulld this be my water heater going bad and if so can I fix it? Thanks teddogz

 

[Terry]

Two things,

It could be a water wasting shower head.
You can dump a lot of water real quick with some.

Or the dip tube could be breaking up.
When they do, you will sometimes see little bits in the aerators of the faucets.

If you do replace, I like to go with 50 gallon tanks.