Install Instructions

5 Electrical connections
36
Installation & Service Manual
Temperature Control Settings
Residential heating boilers with inputs of less than
300,000 Btu/hr must be equipped with a control
that automatically adjusts boiler water temperature
in reference to heat load. The Solution boiler is
equipped with outdoor air reset, a feature that
increases the temperature setting of the boiler as
outside temperatures drop and decreases the boiler set
point as outdoor temperatures rise. The temperature
control settings on the Solution boiler can be
customized to meet system requirements.
The two-stage thermostat allows knob adjustment of
up to three parameters: Maximum Set Point (at Low
Outdoor Air), Minimum Set Point (at High Outdoor
Air), and High Fire Offset. The low and high outdoor
air temperatures are factory set at 0°F (-18°C) and 70°F
(21°C) respectively. The heating boiler operating set
point is dependent upon the outdoor air temperature
and the outdoor air reset curve. The reset curve
can be designed to meet system requirements by
specifying the target boiler water temperature at
low and high outdoor air temperatures. Reference
FIG. 5-6 and Table 5C to help determine the proper
settings for your system. If return water temperatures
of less than 140°F are required, follow the instructions
for Low Temperature Bypass Requirements.
Max. Set Point Range
150° - 200°F
Min. Set Point Range
110° - 140°F
High Outdoor Air
Temp.= 70° F
Low Outdoor Air
Temp.= 0°F
Max. Set Point
(Low Outdoor Air Temp.)
Min. Set Point
(High Outdoor Air Temp.)
IMG00274
BOILER
SET POINT
°F
OUTDOOR AIR TEMPERATURE
°F
Figure 5-6_Outdoor Air Reset Curve
Maximum Set Point (Low
Outdoor Air Temperature)
When the outdoor temperature
drops to 0°F (-18°C), the boiler water
temperature will be at the maximum
set point. This is the maximum
heating boiler set point and can be
set using the left-hand knob on the
temperature control (FIG. 5-5). If
outdoor temperatures continue to
drop, the temperature control will
not continue to increase boiler set
point. The temperature range of this
parameter is 150°F (66°C) to 200°F
(93°C). If DHW priority is used, the
controller will change boiler set point
to 180°F (82°C) until water heating
demand is satisfied.