Originally Posted by Pirate4hire
Just to let everyone what I ended up doing....I was going to stay original right up to the moment when testing the tank and it failed. It too quite awhile to get all the sediment out and then to have it leak (around the fitting which holds the gas valve/thermostat) was disappointing.
I've installed a tankless hot water heater and just need to make a couple more slight mods before I post any pics. I have a gas valve assembly for the original Bowen if anyone wants it.
Your experience is not all that uncommon. Often times sediment build up masks pinhole, or leaks.
I've seen some cases where sediment buildup allows anaerobic corrosion to take place under the sediment layer. Other problems arise because sediment can insulate portions of the tank which causes uneven heating, which in-turn causes differing rates of expansion. This can weaken weld seams and material over time.
When the sediment seal is removed the leak is exposed.