3⁄4 × 3⁄4 × 1⁄2 reducing tee is needed so the 1⁄2″ hori-
zontal pipe to hose bibb B can be attached to
the underside of the floor joists. Temporarily
assemble the appropriate tee and a length of
the correct diameter pipe. Secure the assembly
to the lower edge of the floor joists in the
desired location. The face-to-face measurement
for the 3⁄4″ vertical pipe can now be made. Add
the fitting allowance and cut the pipe to length.
If the 3⁄4″ pipe to the water heater runs in the
space between two floor joists, it will pass over
the beam supporting the floor joist near the
center of the basement without any offset. If the
3⁄4″ pipe runs below the floor joists, either the 2″
thick wood plate on top of the beam will need
to be notched, or the 3⁄4″ pipe will need to be
offset using 45° ells.
The length of vertical pipe joining the
reducing tee and the upper 90° ell will be deter-
mined by the height of the horizontal pipe
extending from the 90° ell. Typically, this
distance is not critical unless a heat duct or
other obstruction is or will be in the path of
the pipe.
Installing the Water
Heater
The water supply pipe from the meter
divides into two main branches at the water
heater. One branch is for cold water and the
other branch connects to the water heater to
produce the hot water branch. Beyond the
water heater, the hot and cold branches run
parallel to each other to serve each of the
fixtures.
Code requires that a valve be installed on
the cold water pipe entering the water heater,
Figure 20-3. This allows the water heater to be
turned off when maintenance or replacement is
necessary. This valve turns off the entire hot
water branch because it stops the flow of water
into the water heater. It is very important to
follow the manufacturer’s directions so the
correct openings are used for the installation of
the cold and hot water pipes and the T/P relief
valve. The cold water inlet is fitted with a dip
tube inside the water heater tank that directs
entering cold water to the bottom of the tank. If
this connection were used for either the hot
water pipe or the T/P relief valve, the water
heater would not function properly.
Completing Water Heater
Installation
The following procedure can be used to
complete the installation of the water heater:
Chapter 20 Installing Water Supply Piping
351
Dip tube: Device that directs entering cold water to
the bottom of the water heater tank.
Figure 20-3. A water heater must be located so the
discharge pipe either empties into a floor drain or
extends to the exterior of the building.
1⁄2″ MIPT
Adapter
Blocking per
manufacturer's
specifications
1⁄2″ union
1⁄2″ tee
1⁄2″ cold water
pipe to laundry
and kitchen
1⁄2″ hot
water pipe to
laundry and
kitchen
1⁄2″ tee
1⁄2″ 90° ell
Discharge
pipe
Maximum of
6″ above floor
Floor drain
Ball valve
T/P relief
valve
3⁄4″ × 1⁄2″ × 1⁄2″
reducing tee
3⁄4″ cold
water
pipe
from
meter
1⁄2″ cold water
pipe to
bathrooms
1⁄2″ hot water pipe to
bathrooms