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8. BOILER CONTROL: OPERATION
A. CONTROL OVERVIEW
The P
F
®
boiler control is one of the primary safety
URE
IRE
devices for the boiler. It controls the ignition sequence,
temperature limits, circulators and gas flow to the boiler. It
also provides many unique features.
The control provides 8 central heating modes and 3
domestic hot water modes. To provide maximum
flexibility, several special features are also included.
Table 8.1: Central Heating (CH) Modes
Central Heating Mode
0 (Indoor Thermostat) Default
1 (Thermostat and Outdoor Reset)
2 (Permanent Demand and Outdoor Reset)
3 (Permanent Demand and Setpoint)
4 (Analog 0-10 VDC Input – Setpoint)
Table 8.2: Domestic Hot Water (DHW) Modes
Domestic Hot Water Mode
0 (No DHW)
1 (DHW Tank with sensor)
2 (DHW Tank with thermostat)
Table 8.3: Pump Modes
Pump
Display Text
Mode
0
DHW or CH & DHW pump
1
General pump with 3-way valve
2
Manifold with pump for DHW
Boiler operates when CH TSTAT terminals (#1 & #2) are closed targeting a fixed setpoint
regardless of heating load.
Boiler operates when CH TSTAT terminals (#1 & #2) are closed targeting a variable setpoint
based on outdoor temperature.
Boiler operates to maintain a variable setpoint based on outdoor temperature. When CH
TSTAT terminals (#1 & #2) are closed, 18°F is subtracted from the calculated setpoint.
Boiler operates to maintain a fixed setpoint. When CH TSTAT terminals (#1 & #2) are
closed, 18°F is subtracted from the setpoint.
Boiler operates on setpoint from an external device (BMS) based on a 0-10 VDC analog signal
to provide setpoint.
No DHW tank is used.
The domestic water tank is equipped with a temperature sensor. The P
firing rate based on tank temperature
The domestic water tank is equipped with a thermostat. The P
the thermostat and modulates the boiler firing rate targeting the DHW boiler setpoint. If no domestic hot water
tank is connected, this feature will not function.
The General pump is always on when the burner is on. The CH pump runs on CH
demand. The DHW pump runs on DHW demand. Either the CH or DHW pump runs;
they never run at the same time
The General pump is always on when burner is on. A line voltage (120 VAC) 3-way
valve is operated to supply water to the DHW tank.
This mode is not used for most operations. Consult factory if needed.
BOILER CONTROL: OPERATION
1. Central Heating (CH) Modes:
The P
F
URE
IRE
choose from several different central heating modes.
The following table shows the central heating modes. In
addition, the table shows the display text associated with
each CH mode and a brief description of the operation.
2. Domestic Hot Water (DHW) Modes:
The P
F
URE
IRE
to choose from three different DHW modes.
Description
Input Signal
0-1.5 VDC
2 VDC
6 VDC
10 VDC
Description
URE
Brief Description
®
boiler control allows the installer to
®
boiler control also allows the installer
Target Setpoint
OFF
60°F
123°F
189°F
F
®
control modulates the boiler
URE
IRE
®
F
control responds to the demand from
IRE
35
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