45
The value for “TDiff” is the difference in temperature
between the supply temperature and the target
temperature that will override the minimum off time.
This temperature difference indicates the presence of
a substantial heat load.”
The default value for TDiff is 30°F and can be set to
values between 20°F and 40°F. TDiff can also be
disabled by choosing “Off”. To do this push the down
arrow until “Off” is displayed.
Warm Weather Shut Down
: The PUREFIRE
®
control
will prevent the boiler from operating if the outdoor
temperature is above the temperature chosen by the
installer. This helps to prevent wasting fuel if windows
are open and the indoor temperature drops below the
thermostat value. This function can be activated in
either setpoint or outdoor reset CH modes as long as
the outdoor sensor is attached. This only affects CH
demands. The boiler will continue to operate for
DHW loads regardless of outdoor temperatures.
Maximum CH Input Limit
: The PUREFIRE
®
control
allows the installer to limit the maximum input of the
boiler under a CH load if desired. This can be used
when the boiler is sized primarily for a DHW load and
is oversized for the CH load. This can be set between
50% and 100% and the default is 100%.
E. DOMESTIC HOT WATER (DHW)
1. DHW Modes:
Table 8.2 provides an overview of the domestic hot
water modes. The following are detailed descriptions
of the operation of these modes:
Mode 0 – No DHW
: This is the default mode for the
control. When this mode is selected, the control will
not respond to either a thermistor signal or a contact
closure at the DHW terminals (#5 & #6). There is
also no output to DHW Pump Terminals.
Mode 1 – DHW Store with Sensor
: In this mode, the
P
UREFIRE
®
control accepts a temperature input from an
optional domestic tank sensor (54157). This sensor
provides the DHW water temperature value to the
control. The control targets the user selected DHW
setpoint and modulates the boiler firing rate accordingly.
BOILER CONTROL: INTERNAL WIRING & OPERATION
Table 8.8: Outdoor Design Temperature (ODT) – U.S. Cities
City State ODT City State ODT City State ODT
Mobile AL 29°F -2°C Springfield IL 2°F -17°C Albuquerque NM 16°F -9°C
Anchorage AK -18°F -28°C Indianapolis IN 2°F -17°C New York City NY 15°F -9°C
Juneau AK 1°F -17°C Des Moines IA -5°F -21°C Rochester NY 5°F -15°C
Flagstaff AZ 4°F -16°C Wichita KS 7°F -14°C Greensboro NC 18°F -8°C
Tucson AZ 32°F 0°C Bowling Green KY 10°F -12°C Fargo ND -18°F -28°C
Little Rock AR 20°F -7°C New Orleans LA 33°F 1°C Columbus OH 5°F -15°C
Fayetteville AR 12°F -11°C Bangor ME -6°F -21°C Tul sa OK 13°F -11°C
Sacramento CA 32°F 0°C Portland ME -1°F -18°C Portland OR 24°F -4°C
San Diego CA 44°F 7°C Baltimore MD 13°F -11°C Philadelphia PA 14°F -10°C
San Francisco CA 38°F 3°C Boston MA 9°F -13°C Pittsburgh PA 5°F -15°C
Boulder CO 8°F -13°C Springfield MA 0°F -18°C Charleston SC 28°F -2°C
Denver CO 1°F -17°C Detroit MI 6°F -14°C Sioux Falls SD -11°F -24°C
Hartford CT 7°F -14°C Marquette MI -8°F -22°C Dallas TX 22°F -6°C
Waterbury CT 2°F -17°C Minneapolis MN -12°F -24°C Salt Lake City UT 8°F -13°C
Wilmington DE 14°F -10°C Jackson MS 25°F -4°C Burlington VT -7°F -22°C
Orlando FL 38°F 3°C St. Louis MO 6°F -14°C Richmond VA 17°F -8°C
Tallahassee FL 30°F -1°C Billings MT -10°F -23°C Seattle WA 27°F -3°C
Atlanta GA 22°F -6°C Omaha NE -4°F -20°C Spokane WA 2°F -17°C
Boise ID 10°F -12°C Carson City NV 9°F -13°C Morgantown WV 8°F -13°C
Idaho Falls ID -6°F -21°C Manchester NH -3°F -19°C Green Bay WI -9°F -23°C
Chicago IL -4°F -20°C Atlantic City NJ 13°F -11°C Cheyene WY -1°F -18°C
DANGER
Water temperatures over 125°F can instantly cause
severe burns or death from scalding. Children, elderly
and disabled individuals are at the highest risk of
scalding. See instruction manual for the indirect tank
before setting the water heater temperature. Instruct
users to feel the water temperature before bathing or
showering. Anti-scald valves are recommended.
Be sure to use only the tank sensor indicated. Other
sensors will not provide accurate tank temperatures
and may cause severe personal injury due to scalding.
WARNING
To Next Page
Loading...
Need help?
General