Potable/Space Heating - Rheem Residential 40 Gallon Use & Care Manual

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.
Hot water
supply to
heating
unit
Tee fitting for vertical hot
water supply lines.
Hot water
supply to
house
Hot water supply
to heating unit
Tee fitting for horizontal hot
water supply lines.
Typical Piping Diagram for Combination Potable/Space Heating Installation
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.
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.
Isolation valve in hot water supply
line to heating unit (not supplied with
water heater)
Temperature and Pressure Relief
Valve, tie to location approved by
local code
Gas line to water heater
Temperature and pressure relief
valve discharge line
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
All water piping shall be insulated
in accordance with Local and State
Energy Code.
18 18
Combination Potable and Space Heating Application
Hot water
supply to
Tee fitting must be installed as shown.
house
This ensures that any air in the water lines
will be purged through the domestic water
faucets and showers.
From HOT DANGER: When this system
outlet on
requires water for space heating at
water heater
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
From HOT
reduce the scald hazard potential.
outlet on
water heater
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.
Minimum of 2'-0" developed length
of 3/4" type "L" copper from the
water heater connection.
Air vent
Gas Fired
Water Heater
3/4" Tempered
domestic hot water
supply to house.
3/4" Shut-Off Valve (Typ.)
Heat Trap
6" Min.
2 Gallon Thermal
3/4"
Expansion Tank
Shut-Off
Valve (if required-not
supplied with water
(Typ.)
heater)
3/4" HWS &
HWR to Heating
Coil.
Drain valve
(not supplied with
water heater)
Isolation valve in
cold water return
line from heating
unit (not supplied
with water heater)
Gas Direct Vent
discharge must comply
with Local and State
Code
Combustion Air Inlet
Openings
6" Air Gap
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.
Pressure Gauge
3/4" Check Valve with 1/8" Hole
3/4" Shut-Off Valve (Typ.)
3/4" cold water supply
Vacuum Relief Valve
Electronically controlled pump timer.
(Not Supplied)
Activates every 6 hours for 60 seconds.
Wire to bronze pump.
If required, install per local codes
and valve manufacturer's
instructions.
Piping loop between water
heater and fan coil shall
be flow guard gold CPVC
or equal
Hot water
to space heater
Hot water coil
All bronze pump.
Check valve
internal in pump.
Air bleed valve.
Water Sample Tap.
To HVAC
Unit.
FAN
T ON
OFF
HEAT
COOL
Air Handler