How do you install two hot water heaters together?

To install two hot water heaters together, first ensure both units are compatible with your system. Connect them in a parallel configuration, where the cold water supply feeds both heaters simultaneously, and the hot water output from each flows into a common pipe. Install appropriate valves and fittings to manage the flow, and ensure proper venting and safety measures are in place. Finally, check local building codes for compliance and consider consulting a professional for installation.