galvanized and copper electrolysis

[auji]

Hello,
I am remodeling a bathroom and would like to replace some galvanized pipe with copper. Should I be concerned about electrolysis? Can I just connect to the galvanized with a copper bushing? Thank you.

[16x80]

auji

In my experience electrolysis is a major problem when joining copper to galvanized. Its as easy to go buy a couple dialectic unions to make the joint other than have to worry about when and how you plan on repairing the joint!

16x80

[auji]

Thanks 16x80.

Would there be a reason to replace galvanized pipe with cpvc or copper besides ease of installation? This system is under the house in an area that can freeze.

Also... Can you tell me why there is a 1/2" bypass on the hotwater heater? It takes off just before the valve to the heater, on the street side and goes to the line comming off the heater with hot water.

Thank you.
[8]

[16x80]

Updating you pipe is a viable solution to galvanized pipe any day, question is is it worth your time. Depends on how long you plan on staying in the house, It might help the resale value also!
As with any pipe in a space that can freeze you should have heat tape on all the exposed pipe, insulate it with a pipe insulation, keep all extreme cold from the bare metal pipe. Typically you would have bare pipe on the warm side of the insulation in the floor and walls, this would be enough to prevent freezing. But in older homes you don't have the luxury of this standard practice.

On the bypass thing, You should have the pipe from the street to a valve, from the valve you should have one pipe leading to the inlet/cold side of the water heater and the other side of the pipe going to your cold on the house supply. The hot from the water heater should be feeding the hot water pipes in your house. If you have a cold water pipe feeding into your hot water line coming out of your hot water heater then you are defeating the purpose of hot water.

16x80