General Boiler Operation; Boiler Freeze Protection - Watts AERCO EXT Installation, Operation & Maintenance Manual

Modulex EXT Commercial Series
CHAPTER 3: Technical Features & Dimensions
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Operation modes:
o Ability to control power to the individual heating elements for any calibration with or without
confidential code access.
o Production of A.C.S. (Active Cooling System) by NTC sensor of priorities for control by boiler
feed pump or by three-way diverter valve controller.
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Ufly electronic controller included.
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BCM (Boiler Communication Module) included.
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Ability to control power of the individual heating elements.
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Control of heat demand: constant or remote setpoint.
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Monitoring of operating status and temperature.
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Reporting of alarms.
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Setting of parameters.
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Emergency operation prevents the boiler from shutting down as a result of the interruption of
communication with a control system or any remote control unit.
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Alarm management.
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Alarm reset input.
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Warning alarm relay.
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Stainless steel condensate collector tank with siphon, drain trap, and smoke chamber.
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Easily removable stainless steel panels painted for outdoor installation.
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Built-in air vent

3.2 General Boiler Operation

The boiler is operated from the Ufly controller. The Boiler Control Manager (BCM) is used for
Modbus communication as well as backup operation. The boiler management logic automatically
fires the maximum number of simultaneously operating heating elements in order to maximize heat
production and overall efficiency. Burner efficiency and a high heat exchange between surfaces
contribute to the reliable and efficient output power. The various components are designed to work
together so that operating time is shared equally among the components, thus reducing
maintenance and labor costs.
The hot water moved by the pump is pushed to the return of the primary flow of the hydraulic
separator. From here a second pump will distribute the hot water to the various destinations. The
cooled return water is drawn by the pump through the hydraulic separator to resume the cycle via
the boiler.
W A R N I N G !
If installing to an outdoor location where freezing temperatures may occur, it is necessary to install
devices and/or materials to prevent any freezing in the condensate drain and the Flow and Return
manifolds. Failure to do so may cause serious damage to the equipment.

3.3 Boiler Freeze Protection

Should the boiler water outlet temperature decrease to less than 44.6°F (7°C), the system pump
will start, and all heat modules will start at minimum output until the minimum setpoint (BCM
Parameter 31) is reached. This protection device is exclusively for the boiler. For the protection of
the whole system, a second freeze protection thermostat is necessary to switch on the heating
system pump.
NOTE: If glycol is used as antifreeze in the boiler, a back-flow preventer must be installed in the
make-up/fill line.
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