Whirlpool 195863 User Manual

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15
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.
• 
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 120°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 for additional instructions on 
the safe and correct installation and operation of this water 
heater.
Coil
Must be vertical to
remove air bubbles
Figure 16
Typical Tempering Valve Installation
Combination Space Heating/Potable
Water Heating System
Domestic
Hot Water
Out
Tempering
Valve
Hot
Water
Out
Unions
Cold
Water
Inlet
Pump
Flow Control
Valve
To
Air
Handler
Out
In
Air
Handler
Shut-off
Valve
Massachusetts code
does not allow this
type of installation.
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 120°F. A 
tempering valve or other temperature limiting valve must 
be installed in the water supply line to limit the supply 
temperature to 120°F.
NOTE: Solar water heating systems can often supply water 
with temperatures exceeding 180°F and may result in water 
heater malfunction.