No water from hot water heater

[Last Boat]

This weekend I could not get water (hot or cold) from any hot water facet. I must have had a pressure build up in my tank. I first pulled the pressure relief valve and nothing came out. I then opened the water drain and nothing came out. I then shut off the cold water feed to the hot water heater and pulled the output (red) hose from the hot water heater tank. I then opened the cold water feed to the heater and air escaped and them the water began to flow. I then shut off the cold water feed to the hot water heater and reattached the (red) output hose from the hot water heater tank. The hot water began to work as normal. I have no idea how the pressure in the tank just appeared, but I now know how to relieve it. If anyone has any ideas as to how the pressure builds, please let me know.
Nelson Gainey
Last Boat
C350 #345

[KenKrawford]

Nelson, it almost sounds like you had an air lock in your system. Had you switched water tanks just before this happened? Other than that, I'm at a loss explaining your problem.

[R.B.]

I am guessing here ... but i noticed when I switched my supply valves under the kitchen sink after 1 tank went dry that the pump needed to work for awhile before it got water from the full tank. Is it possible that in switching the tanks the pump pushes air in the system and possibly creates an air lock down stream?? Just a thought.

[Last Boat]

Hey Guys,
I did run out of water in the forward tank, but I have run out of water several times with no problems for the hot water system. I hope I don't have to manually vent the hot water tank each time I run out of water. I would think the pressure relief valve would vent this pressure, but it didtn't. Thanks for your replies.
Nelson Gainey
Last Boat
C350 #345

[Hans Grasman]

I am on a short SW Florida cruise and the hot water feed is blocked.
I remember somebody giving specific instructions on how to remedy this.
Noticed that water hose clamps are not reusable so I need to go to hdwe store to replace them.
But in meantime if somebody can give me a link to the fix I would appreciate it.
Thank you

[Last Boat]

Hans,
I would shut off the hot water feed from the water manifold and pull the hot water output hose from the hot water heater. Turn on the hot water feed from the manifold and the pressure will release out of the tank and water will begin to flow, then shut off the hot water feed from the manifold and put the hose back on the tank. This worked for me. Lots of luck!
Nelson Gainey
Last Boat
C350 #345

[Hans Grasman]

Nelson
Thank you for your reply. Yes, I read your earlier message and follow the instructions you listed but it did not fix the problem.
I believe there is a check valve in the hot water heater and it went on the blink. I will call Seaward today.
I also posted on the Yahoo C350 message board and received replies.