About Outdoor Reset - Bradford White Brute BNTH1000 Installation And Operation Instructions Manual

Brute
B
TM
RUTE. BOILERS AND VOLUME WATER HEATERS, 1,000 & 1,200 MBTU/h
on TB7.
2. Set the outdoor reset and warm weather
shutdown parameters as desired.
How to get there – Outdoor Reset Screen and
Warm Weather Shutdown Screen
Home Page <Press View Lead/ Lag button> Lead/
Lag Screen <Press Lead/ Lag Master button>
Lead/ Lag Screen <Press Configure button> Lead/
Lag Master Configuration Screen <Press Advanced
Settings button>
Select the Outdoor Reset Screen or the Warm
Weather Shutdown Screen
Fig. 92 – Outdoor Reset
For a detailed explanation of the Outdoor
Reset function, see the section titled "About
Outdoor Reset" which follows.
Fig. 93 – Warm Weather Shutdown
When enabled, the Warm Weather Shutdown
feature will turn off the Central Heating
functions when the outdoor temperature
exceeds the setpoint. This prevents the
system from running when there is no need for
heat.
Enable -
These options determine how quickly
the system shuts down after the outdoor
temperature rises above the setpoint. The
options are Shutdown immediately/ After
demand ends/ Disabled.
Setpoint -
If the outdoor temperature is higher than
this, the system will shut off the Lead/Lag
Central Heating functions.

About Outdoor Reset

The Outdoor Reset feature calculates a correction
for the Lead/Lag setpoint depending on the outdoor
temperature. This allows the system to adjust for
changes in the outdoor temperature and run more
efficiently.
The Show Line button at the bottom of the Outdoor
Reset screen displays a curve which shows
how the system will behave at different outdoor
temperatures. See Fig. 94.
Fig. 94 – Show Line Screen
The display shown above show the action of the
system with one possible group of settings. The
green line shows the setpoint used by the system.
• Without Outdoor Reset, this would be a
constant 120°F (or whatever value you chose),
regardless of the outdoor temperature. The
green line in the graph would run straight
across the display.
• However, with the Outdoor Reset feature
turned on, the system will adjust for changes
in the outdoor temperature. Let's take a
detailed look at behavior of the setpoint,
shown by the green line in the display. For
cold outdoor temperatures (below 32°F), the
setpoint remains unchanged (120°F). As the
temperature begins to rise above 32°F, the
Outdoor Reset function causes the setpoint to
be lowered. At these warmer temperatures,
the heating load on the system is not as
great, so the system does not have to reach
as high a temperature to handle the load. As
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