Connect Hot and Cold Water Lines
Next, install the plumbing lines to the water heater.
- If the new water heater inlet and outlet openings do not line up exactly with the old plumbing, then use flexible copper supply lines.
- Add a shut off valve to the cold water supply if one dose not already exist.
- Connect the pipes using dielectric unions to prevent an electro-galvanic action called electrolysis which will damage your pipe connections and water heater.
- li]Sweat the copper joints or use Teflon tape on threaded copper, and use pipe dope or joint compound on galvanized fittings.
Once the water lines are installed you're ready to install the fuel source.
- Connect the gas line to the gas burner control valve.
- Use a flexible gas line if needed.
- Check for leaks by turning on the gas supply valve and brushing on a soapy water solution onto the gas union and all gas joints, like that at the burner control valve. If you see any bubbles, the connection is leaking and needs to be tightened. If you still cannot get a good seal without bubbles, call the gas company or a plumber for assistance.
- For electric water heaters, connect the power lines and ground wire to the water heater junction box.

