Electric Water Heater Expansion Tank - Bondiing?

Installing a new electric water heater in cottage. Have noted in plumbing how-to books, that an expansion tank was situated on the cold water line before entering the water heater cold water inlet.

Is this a new requirement, and what is the benefit. Water heater will be on a well, not city water supply. It will have its own expansion tank coming out of the well.

Also on natural gas fired water heaters, should you bond the hot and cold water pipes to the natural gas pipe as well. Assuming that all water heaters whould be bonded.

Thanks.

A thermal expansion tank is need only if there is a check valve in the supply line that would prevent the expansion from being absorbed in the water supply. This usually applies to city water supply when there is a pressure regulator valve or a check valve in the water meter. Neither of these apply to your situation. Frankly, I don't even know what you mean by "bonding" pipes together. I have a professionally installed gas heater and the lines are simply connected to the heater with flex copper. Perhaps some of the learned pros will know what you are referring to.

Chuck,

I would not electrical bond your new electric water heater to your gas line.

I no that old school, grounding to gas pipe was the norm.
But now a days, it may not meet your local code. You should have a ground wire from the power source.

As far as an expansion tank, your water well tank should work very good, without another tank.


Have a nice day.


DonL.