14
Figure 16
Typical Tempering Valve Installation
Combination Space Heating/Potable
Water Heating System
Drain Pan
Drain
Unions
Tempering
Valve
Coil
Air
Handler
Shut-off
Valve
To
Air
Handler
Massachusetts code
does not allow this
type of installation.
Pump
Flow Control
Valve
In
Out
Domestic
Hot Water
Out
Cold
Water
Inlet
Hot
Water
Out
Solar Installation
If this water heater is used as a solar storage heater or as a
backup for the solar system, the water supply temperatures
to the water heater tank may be in excess of 115°F. A
tempering valve or other temperature limiting valve must
be installed in the water supply line to limit the supply
temperature to 115°F. The unit must be set to standard
mode (See Operating the Temperature Control System
section). NOTE: Solar water heating systems can often
supply water with temperatures exceeding 180°F and may
result in water heater malfunction.
Figure 15B
T&P Relief Valve Insulation
T&P Relief Valve
T&P Relief Valve
Drain Line
Manual Relief Lever
T&P Relief Valve Insulation
T&P Relief Valve and Pipe Insulation
(Some Models)
1. Locate the T&P Relief Valve on the water heater.
2. Locate the slit running the length of the insulation.
3
Spread this slit open and slip it over the T&P Relief Valve.
See Figure 15B. Apply gentle pressure to the insulation
to ensure it is fully seated on the T&P Relief Valve. Once
sealed secure the insulation with a section of tape.
IMPORTANT: The insulation or tape should not block
or cover the T&P Relief Valve drain opening. Also the
insulation or tape should not block or hinder access to the
T&P Relief valve manual relief lever.
4. Next locate the hot water (outlet) & cold water (inlet) pipes
to the water heater.
5. Select one of the sections of pipe insulation and locate the
slit that runs the length of the insulation.
6. Spread the slit open at the base of the insulation and slip
it over the cold water (inlet) pipe. Apply gentle
pressure along the length of the insulation to ensure it is
fully seated around the cold water pipe. Also ensure that
the base of insulation is flush with the water heater. Once
seated, secure the insulation with a section of tape.
7. Repeat steps 5 through 6 for the hot water (outlet) pipe.
Special Applications
Combination Space Heating/Potable
Water System
Some water heater models are equipped with inlet/outlet
tappings 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.
•
The unit must be set to standard mode (See Operating
the Temperature Control System section).
•
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 heater piping.
•
If the space heating system requires water tempera-
tures in excess of 115°F, a tempering valve or an anti-
scald device should be installed per its manufacturer’s
instructions in the domestic (potable) hot water supply
to limit the risk of scald injury.
•
Pumps, valves, piping and fittings must be compatible
with potable water.
•
A properly installed flow control valve is required to pre-
vent thermosiphoning. Thermosiphoning is the result
of a continuous flow of water through the air handler
circuit during the off cycle. Weeping (blow off) of the
temperature and pressure relief valve (T & P) or higher
than normal water temperatures are the first signs of
thermosiphoning.
•
The domestic hot water line from the water heater
should be vertical past any tempering valve or supply
line to the air handler to remove air bubbles from the
system. Otherwise, these bubbles will be trapped in the
air handler heat exchanger coil, reducing the efficiency.
•
Do not connect the water heater to any system or
components previously used with non-potable water
heating appliances when used to supply potable water.
Some jurisdictions may require a backflow preventer
in the incoming cold water line. This may cause the
temperature and pressure relief valve on the water heater
to discharge or weep due to expansion of the heated water.
A diaphragm-type expansion tank suitable for potable
water will normally eliminate this weeping condition. Please
read and follow the manufacturer’s instructions for the
installation of such tanks.
Also see “Water System Piping” (Page 12) for additional
instructions on the safe and correct installation and
operation of this water heater.
