Tee fitting for vertical hot
water supply lines.
Hot water
supply to
house
From HOT
outlet on
water heater
Hot water
supply to
heating
unit
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 horizontal hot
water supply lines.
From HOT
outlet on
water heater
Hot water
supply to
house
Hot water supply
to heating unit
Combination Potable and Space Heating Application
Tee fitting must be installed as shown. This
ensures that any air in the water lines will be
purged through the domestic water faucets and
showers.
DANGER: When this system requires
water for space heating at elevated
temperatures (above 125°F [52°C.]), 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.
DANGER: 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.
DANGER
:
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.
Notice:
50' - 0" maximum distance
from water heater to fan coil
(developed length) is required for
Massachusetts State.
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)
NOTE: 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.
All water piping shall be insulated in
accordance with Local and State Energy
Code.
Isolation valve in
cold water return line
from heating unit (not
supplied with water
heater)
Nominal 3/4" size mixing or tempering valve
(refer to warning above). Follow mixing or
tempering valve manufacturer’s instructions for
installation of the valve.
Temperature and pressure relief
valve discharge line
Air Handler
Drain valve
(not supplied with
water heater)
Hot water
to space heater
Temperature and Pressure Relief
Valve, tie to location approved by
local code
See diagrams above for proper
pipe application for vertical
or horizontal supply lines.
Isolation valve in hot water supply line
to heating unit (not supplied with water
heater)
3/4" cold water supply
3/4" Tempered
domestic hot water
supply to house.
Gas line to water heater
6” Air Gap
Combustion Air Inlet
Openings
2 Gallon Thermal
Expansion Tank (if
required-not supplied
with water heater)
Air vent
Heat Trap
6” Min.
3/4" Shut-Off Valve (Typ.)
3/4" Check Valve with 1/8" Hole
Pressure Gauge
3/4" Shut-Off Valve (Typ.)
3/4" Shut-
Off Valve
(Typ.)
Piping loop between water
heater and fan coil shall
be flow guard gold CPVC
or equal
Hot water coil
All bronze pump.
Check valve
internal in pump.
Air bleed valve.
Water Sample Tap.
T
FAN
ON
OFF
HEAT
COOL
To HVAC Unit.
Electronically controlled pump timer.
Activates every 6 hours for 60 seconds.
Wire to bronze pump.
3/4" HWS & HWR
to Heating Coil.
Minimum of 2'-0" developed length of
3/4" type "L" copper from the water
heater connection.
Water Heater drain pan installed in
accordance with the Local and State
Code
Water Heater to be in accordance with
the Local and State Energy Code
Gas Fired
Water Heater
Gas Direct Vent discharge
must comply with Local
and State Code
Vacuum Relief Valve
(Not Supplied)
If required, install per local codes
and valve manufacturer’s
i
i
120° to 130°
140°
15