In this video, This Old House plumbing and heating expert Richard Trethewey shows a quiet, efficient way to produce domestic hot water.
1. Drain and remove the old water heater.
2. Install a plywood panel against the basement wall, then mount the new hybrid water heater to the panel.
3. Connect the heater’s exhaust vent to the old vent pipe.
4. Run a fresh-air line down into the top of the water heater.
5. Make the hot- and cold-water connections to the existing water-supply lines.
6. Connect a new gas line to the side of the heater.
7. Install a temperature-and-pressure relief valve with discharge pipe.
8. Attach a condensate line with limestone neutralizer and pump to the underside of the heater.
9. For larger homes, also install a recirculation pump to ensure hot water is available at distant plumbing fixtures.
10. Turn on the heater and then adjust the water temperature to 120-degrees F.