Water Heaters - I have dark color water. Home used every few months. Tank Bad?

My wife and I are travel nurses and only home 3-4 times a year for 20 days at a time. We bought this home 1 year ago. When we fill the tub with water, it is ok. Same for showers and such. But after filling the tub once, if we fill it a second time, the water has a tea stained look to it. Is this because the water is sitting in the hot water tank so long? Rust? Can it be flushed out or cleaned or do we need to get a new hot water heater. The unit is 7 years old as that is how old the house is. If applicable, would anyone suggest the tank less water heater? Thanks for any thoughts.

might want to flush the HW tank,shut it to PILOT on the gas valve ....close the cold water feed,and connect the hose to the bottom and drain it out.just after 10 minutes open the relief safty to vent the balance of the water out.then open up the cold water feed 2 turns to allow water to flush the tank and drain out.if you open the cold water all the way just shut the relief valve becuase the water will fill faster then it can drain and it will come out the relief.might want to drain down 2X if you see rust color the whole time.when your done just close the drain let the cold feed run and put the gas valve back to ON,and it should light off to dial setting.

Your tea colored water can also be from the minerals in the water.
Since you don't use the water that often, it has time to build up.

When the brown water starts coming out. Does it clear up after a short time?
This is a very common occurance. Small pieces break off form time to time. More ofter on facets that are not used very often.


Travis

No. Once it turns tea colored, it seems to stay that way for some time. Coming out the faucet, it can't been seen. But in the white tub, it is.