Page 26

GT INSTALLATION AND OPERATION INSTRUCTIONS

SENTRY 2100T CONTROLLER

Figure 37 - 2100T Display Screen

CAUTION: The T4.0 controller can only be used on the GT-400 and the T2.0 on the GT-150 & 200. Misapplication of the controller will result in improper boiler operation.

The Sentry 2100T controller is the central controller for the GT boiler. The Sentry handles all of the combustion logic, along with the energy management functions. The Sentry 2100T operates in two different modes, Conventional or Reset, see Figures 35 & 36.The mode is automatically determined by the presence of the outdoor sensor. When the Sentry 2100T detects the presence of the outdoor sensor the controller will operate in the Reset Mode. If the outdoor sensor is not installed, the controller will operate in the Conventional Mode.

NOTE: If the outdoor sensor is connected after the boiler has been started power to the boiler must be shut off and then turned back on.

Boiler Modulation

The GT boiler employs a pneumatic modulation system. This modulation system increases or decreases the speed of the blower to meet the heating demand. The gas valve pressure regulator senses the air pressure and adjusts the gas fl ow to ensure correct combustion. The term “Set Point” is used to indicate the desired temperature that the GT will maintain by increasing or decreasing the input.

Indirect Water Heaters

The Sentry 2100 comes with an input and output for

a120-volt indirect pump. When the A and C terminals are closed, dry contact, the boiler will go immediately to indirect domestic mode, whereby the indirect pump is activated, and the boiler will modulate to the LO setpoint.

Sentry Display

The Sentry 2100T contains four green lights that illuminate to indicate the boilers state of operation, Figure 37.

Figure 35 - Conventional Mode Operation Chart

Burner/Bruleur - Indicates that the ignition system is activated.

Circ. - Indicates that the heating pump is energized.

Circ. Aux.- Indicates a call for DHW, and Indirect pump or 3-way valve is activated.

Thermostat Demand - Indicates that terminals T-C are closed, iniating a call for heat.

The LED screen will display one of four values. A light will illuminate above the function to indicate what information is being displayed.

Water Temp - Indicates that the display is showing the boiler water temperature.

Air - if the air sensor is used. When illuminated, indicates that the display is showing outdoor air temperature.

Gas Input Value - Indicates the current input level. Figure 38 must be used to determine the actual input. GT-150 use 46 to 240, GT-200 use 40 to 240 and GT-400 use 35 to 195.

DHW Temp. - indicates that there is a call for domestic hot water.

 

T-C & A-C Open

T-C Closed & A-C open

T-C Closed & A-C Closed

T-C Open & A-C Closed

Condition

Standby

Heating Only

Domestic Only

Domestic Only

Set Point

HI

L0

L0

Burner On

HI - DIF

LO-10

LO-10

Burner Off

HI + 10

200°F

200°F

Heat Circ.

Off

On

Off

Off

Aux. Circ.

Off

Off

On

On

Figure 36 - Reset Mode Operation Chart

 

T-C & A-C Open

T-C Closed & A-C open

T-C Closed & A-C Closed

T-C Open & A-C Closed

Condition

Standby

Heating Only

Domestic Only

Domestic Only

Set Point

HI Calc.

L0

L0

Burner On

HI Calc - DIF

LO-10

LO-10

Burner Off

HI Calc + 10

200°F

200°F

Heat Circ. (C1)

Off

On

Off

Off

Aux. Circ. (Ap)

Off

Off

On

On

Page 26
Image 26
Smith Cast Iron Boilers GT Series manual Sentry 2100T Controller, Boiler Modulation, Indirect Water Heaters, Sentry Display

GT Series specifications

Smith Cast Iron Boilers GT Series has become a benchmark in the hydronic heating industry, renowned for its exceptional performance, durability, and efficiency. This series is designed to cater to diverse heating needs, making it a popular choice among both residential and commercial applications.

One of the standout features of the GT Series is its robust cast iron construction. The cast iron sections offer superior thermal mass, allowing for better heat retention and distribution. This characteristic ensures that the boiler operates efficiently, maintaining comfortable temperatures even during extreme cold weather conditions. The engineers at Smith have meticulously designed each section to provide maximum strength and longevity, resulting in a boiler that can withstand the test of time.

The GT Series also incorporates advanced combustion technology. It utilizes a high-efficiency burner that optimizes fuel consumption, resulting in lower operating costs for homeowners and businesses alike. The boiler is engineered to accommodate a variety of fuel types, including natural gas and propane, giving users flexibility in their energy choices. This adaptability not only enhances efficiency but also promotes environmental sustainability by allowing for the use of cleaner fuel sources.

Another notable technology featured in the GT Series is the electronic control system. This system simplifies boiler operation and enhances user convenience. The intuitive interface provides real-time feedback and diagnostics, making it easier for technicians to perform maintenance and troubleshoot any issues that may arise. Additionally, the boiler’s modulating operation adjusts the burner output according to the heating demand, further improving efficiency and comfort.

Moreover, the GT Series is designed with user-friendly installation in mind. Its compact footprint allows for easy integration into existing heating systems, minimizing space requirements. Additionally, the boiler is equipped with convenient access points for maintenance, ensuring that servicing is straightforward and can be performed without extensive downtime.

Lastly, the Smith Cast Iron Boilers GT Series is designed to meet stringent safety and performance standards. Featuring multiple safety controls and systems, it provides peace of mind for users. With a commitment to quality, efficiency, and performance, the GT Series stands out as a leading solution for hydronic heating, catering to the evolving needs of today’s energy-conscious consumers.