Main panel is grounded using the main copper water line. 1970 build.
The hot water, cold water and gas lines were bonded together but the conductor did not go all the way back to the panel. Is this proper since the main water line is the ground or does the bonding conductor still need to go all the way back to the panel?
Why were the gas lines bonded? Were they CSST?
And no, they do not need to go back to the panel.
No CSST in this home. The jurisdictions up here want the black pipe gas lines bonded to avoid the risk of the pipes becoming energized and staying that way. In every case I have seen so far, the bonding conductor returns to the main panel. This is the first time I have not seen it return to the panel. I am assuming they were thinking that since the main copper water line is the grounding conductor, it meets the requirements. Just trying to make sure.
With the water line being the grounding electrode it would/should be bonded to the panel(s) and the grounding electrode system.
So if the hot water, cold water and gas lines were bonded together all of the individual components of the grounding electrode system and metal 'lines" would be bonded together.
The metallic water pipe is the grounding electrode. The hot, cold and gas are bonded together with a bonding jumper, the water pipe electrode is connected with a GEC (grounding electrode conductor). Bonding jumpers are not required to return all the way back to the service.
The bonding jumper to the gas pipe is not required by the NEC but its permitted to be installed. Bonding the gas pipe is a function of the EGC in the branch circuit feeding the gas appliance.
From what you’ve described the installation is code compliant.