clock menu more-arrow no yes

How to Install an Instantaneous Water Heater

In this how-to video, This Old House plumbing and heating expert Richard Trethewey gets in hot water

In this video, This Old House plumbing and heating contractor Richard Trethewey explains how to install an instantaneous water heater.

1 Use template to mark position of vent hole on exterior wall of basement.
2 Bore center pilot hole for vent using a 3/8-inch-diameter masonry bit.
3 Cut vent hole through wall using large-diameter masonry hole saw; check installation instructions for exact hole diameter.
4 Using black iron pipe, run new gas line from gas meter to heater location.
5 Mount water heater to wall using brackets and bolts provided.
6 Assemble vent pipe, starting with the elbow at top of heater.
7 Attach the exterior portion of the vent pipe onto the heater's elbow from outside.
8 Connect the new gas line to the heater.
9 Run new water line from the heater using copper tubing.
10 Connect water line to the home's plumbing system.
11 Open the valve to purge air from the system; catch expelled water in bucket.
12 Test the heater to ensure the burner ignites.