I need my water heater replaced & the plumber that came out seams to be finding ways to increase the bill. I live in northern Ca & have a natural gas water heater. Are the following items necessary? 1. bonding & grounding 2. gas drip leg 3. expansion tank

Bonding and grounding? I don't understand. That sounds like electrical work.

Drip leg? Yes, but you should already have one.

Expansion tank? Yes if you have a check valve on the cold water input. But then you should already have one if you have check valve. Local codes may require such upgrades upon replacement. Check with local authorities.

Hi all:

Bonding and grounding is necessary if using the newer corrugated steel gas piping system. In my area, believe it or not, we need to have an electrician pull an electrical permit and then do the grounding and bonding.

Older black steel gas piping should not require grounding or bonding.

Harold covered the rest very well... :)

MARK