Originally Posted by Vasco
This hot water tank can only be drained through the cold water inlet at the bottom of the tank. This inlet has a non-return valve in it. To drain remove the in and out lines. Stick a piece of thick wire into the cold water inlet. This will allow the water to flow out. Make sure the "out" (hot) line is removed to allow air into the tank.
The Atlantic Marine tanks just have female tappings into which brass nipples were threaded. The check valves were usually external to the tank or in the cold water feed line.. Any check valve should be clearly visible. I've net yet seen an AM tank with the check valve threaded directly into the cold feed but what installers do could make it possible....
Cold feed bottom right. Brass nipple. The check valve was in the cold feed line about 18" away from the tank with this installation.
With the SS jacket off the tank..
Originally Posted by deniseO30
If it's old there's a good chance there is sediment in the tank. It would make draining difficult since it blocks the opening to the drain. the old Raritain HWH on my boat had allot of sediment in it.
The Raritan tanks are cheap glass lined tanks with an anode. The anode usually rots way, then the porcelain cracks and the tank begins to rust. You don't have anodes or rusting issues on SS tanks like you do with a glass lined tank.. You would have to have a LOT of sediment in your water system to plug the cold water feed on an AM tank... I suspect the OP just never found or knew there was a check valve in the system....