Any recommendation for check valve on hot water heater?

[BAD ORCA]

I just installed a new Isotemp water heater, but I had to install it at the highest point in the system. As a result, when the water pump is turned off, water from the hot water heater back flows through the cold water lines when the cold water tap is turned on. It seems i need a check valve at the cold water inlet. Anything special I need? Lead free brass is all i can imagine but figured I would ask if there is any other considerations I need to make?

 

[dlochner]

Lead free brass is fine, find them at the local big box hardware store.

The reason a check valve is needed on the cold water intake is to prevent hot water from backing up into the cold water system. gravity is only part of the issue, the bigger issue is water expands when heated and it will backup into the cold water piping. Turning the cold water on can give a blast of hot water. This is especially an issue when the tank is heated from engine heat.

 

[BAD ORCA]

Lead free brass is fine, find them at the local big box hardware store.

The reason a check valve is needed on the cold water intake is to prevent hot water from backing up into the cold water system. gravity is only part of the issue, the bigger issue is water expands when heated and it will backup into the cold water piping. Turning the cold water on can give a blast of hot water. This is especially an issue when the tank is heated from engine heat.

HA! yeah thats what happened this morning. I turn everything off when I leave the boat including the fresh water pump. When i returned this morning, i turned on the faucet before turning on the pump to see if the pressure had dropped in the lines indicating a leak from yesterdays installation. To my surprise, the water pressure was normal and not only would not stop but kept getting warmer from the cold water tap. It took me a couple of minutes to realize what was happening. The instructions didn't mention adding a check valve. For a minute I thought I had connected some of the hoses backwards or something.

 

[Stu Jackson]

The instructions didn't mention adding a check valve.

West marine has always had great info. They call them The Advisors.

Try this:

Pressurized Freshwater Systems Guide | West Marine

With helpful diagrams and accompanying text, this article from the experts at West Marine will get you up to speed on freshwater pumps and system components.

www.westmarine.com