Install Instructions

7 Domestic water heaters
Storing the water at a higher temperature and thermostatically
mixing the water increases the available quantity of mixed hot
water, greatly reducing the possibility of condensate forming
on the heat exchanger or in the venting system and helps
prevent water born bacteria growth.
Some states may require a lower water temperature setting for
specific applications. Check local codes or your gas supplier for
domestic hot water temperature requirements.
Remember, no water heating system provides exact temperatures
at all times. Let the system operate a few days at your desired
settings to determine correct settings for your needs.
1. These units are equipped with an operating temperature
control.
2. The control set points are preset to a low test setting when
shipped from the factory.
3. Reset the temperature set points to the lowest settings which
will satisfy hot water demands, eliminate a possible
condensate problem and prevent a risk of scald injury.
4. The High-Fire Offset should normally be adjusted to “0”
when supplying potable hot water for domestic use.
5. Stage firing can be achieved by adjusting the High-Fire
Offset to any value other than zero. Typically, a setting of
3°F is 5°F is suitable for stage firing in a water heater
application. Stage firing of a potable water heater is
normally only used to replace system standby heat loss.
6. All stages of burner operation should fire when there is a
major draw from the potable hot water storage system.
This prevents possible condensate problems and ensures a
rapid recovery of the hot water used.
The High-Fire stage will be delayed by
approximately 10 seconds to allow a
soft start of the water heater.
When water is stored at temperatures
above 125°F (52°C), a thermostatic
mixing valve must be installed on the
hot water outlet from the storage tank
to supply lower temperature water and
prevent the risk of a scald injury.
⚠ WARNING
This water heater, when set at a lower
temperature setting, is not capable
of producing hot water of sufficient
temperature for sanitizing purposes.
• Water temperature over 125°F (52°C)
can cause severe burns instantly or
death from scalds.
• Children, disabled and elderly are
at highest risk of being scalded.
• See instruction manual before
setting temperature at heating
appliance.
• Feel water before bathing or showering.
• If this appliance is used to produce
water that could scald if too hot,
such as domestic hot water use,
adjust the outlet control (limit) or use
temperature limiting valves to obtain
a maximum water temperature of
125°F (52°C).
Location of cold water supply piping
connections
Incorrect piping of the cold water supply to the system
may result in excessive low temperature operation
causing condensate formation on the heat exchanger and
operational problems. You must install the cold water
supply piping in the discharge piping from the heater to
the storage tank. This allows the cold water to be tempered
in the storage tank before entering the heater. See FIG.
7-1, on page 52, and typical installation drawings provided
with the unit for correct piping. Higher water temperatures
reduce condensate formation.
Should overheating occur or the gas
supply fail to shut off, do not turn off
or disconnect the electrical supply to
the pump. Instead, shut off the gas
supply at a location external to the
unit.
⚠ WARNING
Installation & Service Manual
NOTICE
NOTICE
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