14 • Residential Gas Water Heater Use and Care Guide
Space Heating
IN
REMOVE A
MUST BE VERTICAL TO
IR BUBBLES
E
OUT
COIL
AIR
HANDLER
TO
AIR
HANDLER
SHUT-OFF
VALVE
*
EXPANSION TANK
VACUUM
RELIEF
VALVE
COLD WATER INLET
VA
FLOW CONTROL
LV
PUMP
*
SHUT-OFF
CHECK VALVE
†
(1/8” HOLE
DRILLED IN CLAPPER)
VALVE
CHECK
VALVE
†
TEMP/
PRESSURE
RELIEF
VALVE
TEMPERED WATER
TO FIXTURES
(MUST MEET TEMPS LISTED
IN MASS. CODE 248 CMR
†
)
MIXING VALVE
(MUST BE INSTALLED BELOW
TOP OF WATER HEATER
AS PER MANUFACTURER’S
RECOMMENDATIONS)
UNION
UNION
HOT
WATER
OUT
*
MASSACHUSETTS INSTALLATION REQUIREMENTS:
1.) CONNECT ELECTRONICALLY-CONTROLLED TIMER TO AN ALL-BRONZE PUMP. PUMP MUST ACTIVATE EVERY 6 HOURS
FOR 60 SECONDS. TURN PUMP TIMER OFF BEFORE CLOSING PIPING LOOP SHUT-OFF VALVE.
2.) ALL WATER PIPING MUST BE INSTALLED AND INSULATED IN ACCORDANCE WITH MASSACHUSETTS CODE (248 CMR
& 780 CMR).
3.) PIPING LOOP BETWEEN WATER HEATER AND AIR HANDLER MUST BE INSTALLED IN COMPLIANCE WITH 248 CMR.
† REQUIRED FOR MASSACHUSETTS.
‡ PIPING FROM THE TOP OF THE WATER HEATER WITH TEES IS ACCEPTABLE.
WATER HEATER ACCEPTED
BY THE BOARD FOR
INSTALLATION IN
MASSACHUSETTS.
†
TYPICAL MIXING VALVE INSTALLATION
COMBINATION SPACE HEATING / POTABLE WATER HEATING SYSTEM
SEE
NOTE ‡
100’-0” MAXIMUM DISTANCE
FROM WATER HEATER
TO FAN COIL AND BACK
(DEVELOPED LENGTH) NOT
INCLUDING COIL IN HEATING UNIT.
†
Figure 24 - Combustion Space Heating and Potable Water (Typical Installation)
Some water heater models
are equipped with inlet/outlet
connections for use with space
heating applications. If this water
heater is to be used to supply both
space heating and domestic potable
(drinking) water, the instructions
listed below must be followed:
• This water heater is suitable for
combination water (potable) heating
and space heating and not suitable
for space heating applications only.
•
Be sure to follow the manual(s)
shipped with the air handler system.
• This water heater is not to be used
as a replacement for an existing
boiler installation.
•
Do not use with piping that has
been treated with chromates, boiler
seal or other chemicals and do not
add any chemicals to the water
heating piping.
•
If the space heating system requires
water temperatures in excess of
120°F, install a Thermostatic Mixing
Valve in the domestic (potable) hot
water supply at each point-of-use to
limit the risk of scald injury. Install
the mixing valve per its manufactur
-
er’s instructions.
•
Pumps, valves, piping, and fittings
must be compatible with potable
water.
•
A properly installed flow control
valve is required to prevent ther-
mosiphoning. Thermosiphoning is
the result of a continuous flow of
water through the air handler circuit
during the off cycle.
•
The domestic hot water line from
the water heater should be vertical
past any mixing valve or supply line
to the air handler to remove air bub-
bles from the system. Otherwise,
these bubbles will be trapped in
the air handler heat exchanger coil,
reducing efficiency.
•
Do not connect the water heater to
any system or components previ-
ously used with non-potable water
heating appliances when used to
supply potable water.
GETTING STARTED
GET
TING S
TAR
TED
