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Setting the Boiler Temperature
without the Outdoor air Temperature sensor installed
To set the maximum boiler water temperature, simply turn
the MAX. TEMP. dial to the desired setting. The control and
the boiler will then perform to achieve and maintain the set
temperature
The MIN. TEMP. Knob is the boiler water temperature
minimum, or the lowest temperature the water will go before
the unit re-starts. Turning the knob fully counter-clockwise
is the “OFF” position, while turning the knob clockwise, past
the 140° marking, is the “ON” position..
with The Outdoor air Temp - sensor installed
Maximum boiler temp setting is as described above.
The MIN. TEMP. knob in addition to being the mode setting
(on or off) now also has the function of setting the minimum
boiler water temperature. This would be the lowest boiler
water temperature that you want to have based on the
following factors.
1. Outdoor Air Temperature (OAT)
2. Domestic Hot Water Use
a. Hot Water Coil Option
b. Indirect Hot Water Storage
3. Overall Volume of the Heating System
The boiler is designed to withstand lower return water
temperatures however, extended return temperatures
below 140° F can cause condensation in the secondary ash
chamber area and also in the venting system, which could
cause damage in these areas.
NOTE:
If the system is run at the lower temperature settings,
conditions of the firebox, boiler tubes, secondary ash chamber
and venting should be monitored closely. If conditions show
excess condensation, the boiler water minimum temperature
will need to be increased until condensation does not occur.
You should also consider some form of tempering of the
return water system. Discuss this with your plumber.
Control Board Operation
Control Board Operation
aquastat sensor:
This sensor is located in the aquastat
well on the top of the water jacket. This sensor along with the
outdoor air sensor is what the control board uses to regulate
the feed rate based on these two observed conditions. (Boiler
Temp. & Outdoor Air Temperature)
Outdoor air Temperature sensor (OaT)
: This sensor is
located outside the building (on the north side of the house
and out of direct sunlight). The Outdoor Air Sensor is used to
perform hot water reset based on outdoor air temperatures.
When the OAT sensor is installed, at 20° F. or below (outside
temperature), the boiler will operate at the temperature set
on the MAX. TEMP. knob. The boiler water temperature will
decrease by 1° F. for every 1° F. in temperature rise (above
20°) of the outdoor air.
NOTE:
Pellet Boiler Outdoor Air Reset Operation Graph
located on the following page.
Summary of Contents for PB 105
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