You guys replace your hot water heaters ahead of time? I remember when my last one went bad and it was not fun. I guess give it 20 years and replace no mater what? Prophylactically - as a preventative measure?
^^^^It depends. If it's in a spot where no damage would be done by a leak, then I would just leave it. I've changed water heaters that were 40 years old before they started leaking. This is my approach with mine, which is located next to a floor drain on a concrete floor in the unfinished part of our basement.
On the other hand, if it's in a location that would cause catastrophic damage to things like walls and hardwood floors if it were to spring a geyser in the middle of the night or while you're away from the house, then it's a good idea to change them after 10-15 years. Most of them have six-year warranties for a reason.
The tape trick works, but the first two or four numbers of the serial number (depending upon the brand) reflects the year that it was manufactured. Kind of like guitars. Some brands even put the manufacturing date specifically on the sticker that has the model and serial #s.Just put a piece of tape on it with a date.
I'm just not that dialed in to the hot water heater, it isn't on my radar until the water isn't hot or there is a leak. The leak has always presented itself before the tank completely rusts out.
What are you going to do, set a reminder on your cellphone to replace the hot water heater ten or twelve years down the road?