A.
A.
A.

Could be stagnant water, the drain in your sink could be dry when you open your faucet and the water hits the drain it pushes air up and you smell the sewer from your drain, another reason you could have stagnant water in your water heater.

A.

Water heater could be deteriorating

A.

There could be air in the water line

A.

Various situations could be happening your pipes might be galvanized