Water Heaters - Time for a replacement water heater?

Background: I moved into a new house last year. The house is 10 years old with the original gas hot water heater. I'm not sure how often it was drained, etc.

My wife starts up the shower in the morning, and the water rarely gets warm by the time she's done. When I get up and take a shower, the water is fairly hot. I've turned up the temperature above the 120 degree ('Hot') setting, which has helped a little bit.

A plumber friend of a friend suggested it's probably the temperature controller that's gone bad.

A second problem - I decided to test the pressure relief valve, and now it continuously leaks water (probably due to sediment and never being tested before). This seems like an easy repair from what I've read.

My question is, should I try to replace parts and fix the problems, or would it be better to get a new, more efficient water heater? I've read the life span is usually 8 - 12 years.

Would I be able to install a new gas water heater myself, or would I need to hire a pro to connect the gas line? I've done a little plumbing, but not any gas line connections.

Honestly, I would be looking into getting a new water heater.

I say this for a few reasons

1 Age of old heater
2 Cost of water heaters keep going up, not down.
3 better efficiency with the newer water heaters

You night want to be looking into a tankless style water heater such as a Renai. They claim you will never run out of hot water. And much more efficient.

http://www.foreverhotwater.com/model-r75lsi.php

This is just one brand for an example for you to compare with standard water heaters.

Gas piping is not that hard. Just make sure to turn off the gas before starting and check for leaks immediately after you turn on the gas.

Got a truck to haul new heater?
Got any stairs to navigate?
Does your city pick-up old w. heaters?
Worried about gas leaks?
Buy a new one & have it installed..........
No worries.......................................................

I agree with Jhoward as there a lot of other things to consider in replacing the heater yourself.

The "hot" setting should get about 140º water, so the gas control may be bad. The cost to replace that would pay some part of a new one installed, and then you would have a new one, good for 10 to 15 more years.