water inside of heater?

[User]

But the air inside the heater and the heater's glass would be warmer than the tank's water, at least when the heater is on.
Water inside a heater would make me uncomfortable.

Sure. Once it’s switched on and submerged. Take it out to clean it and it’ll drop to ambient air temp and you might get condensation depending on how humid the place was when it was manufactured.

One of mine had condensation in it straight out of the factory packaging. It had been sitting in my basement at 68of for 6 months before I opened it. Been working great for 5 months

 

[ca1ore]

I figure you either believe what the manufacturer says or you don’t. Probably they aren’t out to get you, so I’m inclined to take them at their word. I noted earlier that I prophylactically replace mine on a rotation so that none are older than 3 years. All of my EBJ get a bit of condensation on the inside and in all the years of using them I only had a single failure (though I do not submerge the head). I’m indifferent glass versus titanium. I suppose it’s understandable to think that titanium will last longer, though I know of no data to prove this. I can see inside a glass heater to see if something is amiss; cannot with titanium. I do use titanium, but only those that are ON/OFF, preferring an external thermostat (the whole can’t see inside thing). Ranco is my favored controller.

 

[Ashley Kekua]

it normal to all my heaters. as long as inside isn't drowned then it shall work fine. I see it in mine and run for 10 years not problems