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3. If the thermostat is equipped with an anticipator and it is connected directly to the Mod Con boiler, the
anticipator should be set at .1 amps. If the thermostat is connected to other devices, the anticipator
should be set to match the power requirements of the device it is connected to. See the instruction
manual of the connected devices for further information.
G. OUTDOOR SENSOR
1. There is no connection required if an outdoor sensor is not used in this installation.
2. If using an outdoor sensor, connect wires for sensor to the terminals marked OUTDOOR SEN (shown
in Figure 24) in the electrical junction box. Caution should be used to ensure neither of these terminals
becomes connected to ground.
3. Use a minimum 22 AWG wire for runs of 100 feet or less and minimum 18 AWG wire for runs of up to
150 feet.
4. Mount the outdoor sensor on an exterior surface of the building, preferably on the north side in an area
that will not be affected by direct sunlight and will be exposed to varying weather conditions.
H. INDIRECT SENSOR
1. There is no connection required if an indirect water heater is not used in this installation.
2. The boiler will operate an indirect fired water heater with either a thermostat type aquastat installed in
the indirect tank, or an HTP 7250P-325 tank sensor. When a tank sensor is used, the control will
automatically detect its presence and a demand for heat from the indirect water heater will be generated
when the tank temperature falls below the user selected set point by more than the user selected offset.
The demand will continue until the sensor measures that the indirect water heater temperature is above
the set point.
3. Connect the indirect tank sensor (7250P-325) to the terminals marked DHW SENSOR (shown in
Figure 24) in the electrical junction box. Caution should be used to ensure neither of these terminals
becomes connected to ground.
I. OPTIONAL 0-10 VOLT BUILDING CONTROL SIGNAL
1. A signal from a building management system may be connected to the boiler to enable remote control.
This signal should be a 0-10 volt positive going DC signal. When this input is enabled using the installer
menu, a building control system can be used to control either the set point temperature or the heat output
of the boiler. The control interprets the 0-10 volt signal as follows: When the signal is between 0 and 1
volt, the boiler will ignite. As the signal continues to rise towards its maximum of 10 volts, the boiler will
increase either in set point temperature or firing rate depending on the setting of parameter 17 in the
installer menu. See Part 10 for details on the setting of parameters 16 and 17 for this option.
2. Connect a building management system or other auxiliary control signal to the terminals marked 0-10
VOLT + and 0-10 VOLT – in the electrical junction box (shown in Figure 24). Caution should be used to
ensure that the 0-10 VOLT + connection does not become connected to ground.
J. OPTIONAL HIGH GAS PRESSURE SWITCH
1. If an optional high gas pressure switch is used, it should be installed on the outlet side of the gas valve.
This is normally closed and will open if the pressure goes above 1.5” w.c. on the outlet side.
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