Hot water heater question - still rusty after flush

Factual Questions
1

I’ve got a ~15 year old natural gas hot water heater in my house, and after noticing rust coloured hot water I decided to do a tank flush. This is the first time that it was flushed in at least 3 years (since we moved in anyways), and the amount of red sediment (rust or minerals I don’t know) that I flushed out was amazing. Over 2 days I must have spent 4 hours flushing the tank, and I never did get the water crystal clear but it was much improved. I thought the remaining particles would settle and the problem would be solved.

That was about 2 weeks ago, and we’re still getting off-coloured water from the heater.

I know there’s an rod in the tank that’s supposed to make sure that the tank doesn’t get rusty (anode rod?), but I can’t find much info on it or how to remove it. I’ve also read that the cold water pipe (dip pipe?) may corrode as well, especially in hot water tanks around 15 years old. Finally, the tank itself may be rusty and I could be working on borrowed time until it springs a leak.

At this point I’m not sure what the problem is, so I’m looking for suggestions and solutions. Calling a plumber or replacing the tank is the last on my list, so anything I can do before that would be great.

2

One bump and then I’ll let this die.

Thanks

3

At the ripe old age of 15 (that’s 90 in DHWH years), you’re living on borrowed time with this heater. You don’t know the maintenance history, and since you are still getting dirty water out of it after flushing it would be my edumacated guess that there is considerable sediment and mineral buildup in the heater. This diminishes its efficiency dramatically.

Sorry to say that my recommendation would be to replace it.

4

Thanks Chefguy. That was my thought as well, but I was hoping there was a magic solution out there.

I just called and arranged for a rental. Buh bye dirty water!

5

From the department of redundancy department:

Just curious, why are you heating your hot water?

6

Because it would cool off silly.

7

The sacrificial anode of which you speak is only incorporated in electric HWH units. Dip tubes are typically nonmetallic and have been for a number of years. If your water source is a private well, the simple solution is to install a filtration cartridge immediately after the pressure tank, thereby protecting the heater and the rest of your domestic plumbing from iron sludge. If your water source is municipal, you can do the same, but I’d consider voicing a complaint to the water authority.