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Hot water tank

SBoston Member Posts: 61

I could really use some help here. My electric 60 gal hot water tank went yesterday and I need to install a new one. I noticed that the piping in my house is old and incorrect based on what I have seen in other houses.

What is the proper piping configuration?

Should the cold water line going into the tank be 3/4 with a shutoff? Right now it's 1/2?

Should the hot water side be 3/4 out of the tank and then go to 1/2 for the individual fixtures? Again it's 1/2

Do I need to use Dielectric unions?

Should I have a back flow preventer and expansion tank?

Right now we have no hot water so any guidance you can provide would be very helpful!


  • icesailor
    icesailor Member Posts: 7,265
    Hot water tank:

    Are you in Massachusetts? If so, it should be replaced by a Massachusetts licensed plumber who knows the code requirements. If you are going to change it yourself, it doesn't matter what you do. To meet MA code, it must be connected at the water heater with the same size pipe as the water heater, 3/4" pipe/copper tube. It must have a 1/2" vacuum relief valve on the cold water inlet within 6" of the top of the tank. There must be a 3/4" shut off valve located at the top of the tank. It is allowable with a replacement to reduce to the 1/2" which feeds the water heater coming and going. The temperature/pressure relief valve must be piped with a non-ferrous line to within 10" of the floor. If it is electric, it must have a separate green bonding wire that connects to the neutral system of the electrical system. Bonding through BX or metal conduit doesn't cover it anymore. It needs to have the temperature set to no higher than 125 degrees for an inspection. If it is gas, it needs a gas permit.

    If you aren't a licensed plumber/gas fitter/electrician and are going to do this on your own any, do whatever you are capable of doing.  
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