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
temperatures 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
prevent 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.