CO
LD
HO
T
Typical Piping Diagram for Combination Potable/Space Heating Installation
Spring loaded check valve in
heating unit hot water supply line
and cold water return line (not
supplied with water heater)
NOTICE: This check valve is
incorporated in some heating units.
Refer to the installation instructions
supplied with specific heating unit
to determine if it is required.
See diagrams above for proper
pipe application for vertical
or horizontal supply lines
Gas line to water heater
Cold water return line
from heating unit
Hot water
supply line into
heating unit
Heating unit
Isolation valve in
cold water return
line from heating
unit (not supplied
with water heater)
Mixing or
tempering
valve (refer
to warning
above)
Temperature and pressure
relief valve
Temperature and
pressure relief valve
discharge line
Drain valve
(not supplied
with water
heater)
Water Heater Jacket
Isolation valve in hot water
supply line to heating unit
(not supplied with water heater)
Incoming cold water
supply
Domestic hot water
supply
Air vent
Shut-off valve
Safety Instructions
Installation Instructions
Operating Instructions
Care and Cleaning
T
roubleshooting Tips
Customer Service
15
Supplemental instructions for gas water heaters
installed in potable/space heating applications.
Local codes or plumbing authority requirements may vary from the instructions or diagrams provided in this
manual and take precedent over these instructions.
Tee fitting for vertical hot
water supply lines.
Combination Potable and Space Heating Application
Tee fitting must be installed as shown.
This insures that any air in the water lines
will be purged through the domestic water
faucets and showers.
WARNING: When this system
requires water for space heating at
elevated temperatures (above 125°F.),
a mixing or tempering valve must be
installed in the hot water supply line to
the house in order to reduce the scald
hazard potential.
WARNING: Any piping or components
used in the installation of this water
heater in a combination potable and
space heating application must be
suitable for use with drinking water.
WARNING: If this water heater is
installed in an application intended to
supply domestic hot water needs and
hot water for space heating purposes,
do not connect the heater to an existing
heating unit or components of a heating
system that have previously been used
with a non drinking water system. Toxic
chemicals such as those used for boiler
treatment may be present and will
contaminate the drinking water supply
causing possible health risks. Never
introduce toxic chemicals, such as
those used for boiler treatment, into
this system.
Tee fitting for horizontal hot
water supply lines.
Hot water
supply to
house
From HOT
outlet on
water heater
From HOT
outlet on
water heater
Hot water
supply to
heating
unit
Hot water
supply to
house
Hot water supply
to heating unit
H
He
ea
att ttrra
ap
p
6
6
″″
M
Miin
n..
Thermal Expansion Tank (if
required-not supplied with
water heater)
6
″
air gap
