I didn't think of turning the tank off either. Was told by the company.
I was also told that I would void my warranty if I used the hose they sold at Lowe's without a filter I had to order from the company. It all sounds like a scam to me. I suspect they discovered the problem after they started selling connector hoses, and came out with the filter afterwards to correct it.
At any rate; I am pleased with the heater.
Thanks again for the heads up. Jon