my opinion is based on the fact that most tanks here last 8 to 10 years tops. so his 8 year tank here is already has one foot on banana peel the other in grave, really old tanks like yours may well last longer than ones produced in the last 15 years or so...
OK, what would you opinion be if upon inspection the anode was good on an 8 year old tank?
Have you ever pulled an anode on a water heater?
Sure but if 100 in parts will give him 18 years more service then how do those economics figure in comparison to yours?
So its way less than 800 bucks, DIY, if he is willing to replace the dip tube then installing a new tank is easy.
New dip tube less than $50.
The OP doesnt say why he believes the dip tube is bad, one guess is poor quantity of hot water, which mght be a dip tube, but may also be corrosion built up in the tank. manufacturs largely fixed the dip tube troubles years ago.
Dont you think that if you had the water heater empty and sitting on the floor in your garage that you might be able to look at the anode and peek in the holes on top and perhaps make a better judgement of the condition of the tank than making assumptions based only on the age of the tank?
the economics of tank replacement. assume DIY 400 bucks or pro install
800 bucks, 10 year average tank life, cost per year 40 or 80 bucks, less than a nice candy bar a week.
I agree with you to a point. Where we disagree is I believe that with preventitive maintenance it is very likly that you can reasonably expect a water heater to last 20 or 30 years. Removing sediment, and replacing the sacrificial anode when necessary is going to make that happen.
If you factor in the time value of the money, getting 2 to 3 times the life out of a water heater buys a new TV set and a good one at that.