Smith Cast Iron Boilers GT Series manual Setting Sentry 2100T control, Recommended Settings

GT INSTALLATION AND OPERATION INSTRUCTIONS Page 27

Figure 38 - Input Conversion Chart

		Display Data - Input conversion chart
	400
	350						GT-150			GT-200
	300						GT-400
(000's)	250
	200
BTU	150
	100
	50
	0
	240	215	190	165	140	115	90	65	48	40
					LED Display

Setting Sentry 2100T control

Programming is accomplished by a series of three push buttons located on the bottom side of the control. To enter the programming mode, press the function key once, “RUN” should be displayed on the screen. To scroll through the various menu options depress ↑. To alter the value of a menu option press “Function” once while the menu option is displayed, and the current value will be displayed, then use ↑ for up, and ↓ for down, until the desired value is obtained. To enter the selected value press “Function”, which will return to the menu and store the new setting. When all desired values are set, scroll to the “RUN” menu option, and press Function, which exits the Programming Mode and initiates normal operation. If the control is left in the Program Mode longer than 30 seconds without receiving any input the unit will turn off. Press “Function” once to continue programming or to restart boiler operation.

Below is a list of functions and a description of what they control:

RUN - Stores Values & initiates

LO - Boiler Setpoint for DHW, 80 - 200°F, 27 - 93°C HI - Boiler Setpoint for Heating, 80 - 200°F, 27 - 93°C DIF - Differential, 1 - 40°F, -17°C - 4°C

RES - Sets Outdoor Reset Curve Slope, 70°F, 21°C to HI

SFS - Sets Starting Gas Input Value, 60 to 100 GT150 & 200 is 60 to 100

GT-400 is 45 to 90

HFS - Sets Highest Gas Input Value, 100 to 240 GT-150 & 200 is 100 to 240

GT-400 is 90 to 195

LFS - Sets Lowest Gas Input Value, 40 to 100 GT-150 & 200 is 40 to 100 (see note) GT-400 is 35 to 90

NOTE: LFS must not be set below 48 on the GT150 model. To start the control operation return to “RUN” on the menu and press “Function”. Normal operation will begin.

Recommended Settings

When programming the Sentry 2100T determine what the hottest boiler temperature required for the coldest day will be. This will be the HI SETTING. If an indirect tank is used for domestic hot water, DHW, determine the minimum boiler temperature required to ensure an adequate supply of hot water. This is the LO SETTING. The LO SETTING is only used during a call for DHW, when A and C terminals are closed. Set the LO to the temperature required for the Indirect Water Heater. 140 °F, 60°C or at least 30°F, -1°Chigher than the indirect Aquastat is recommend.

WARNING: Proper control settings must be used to prevent water supplied for domestic use from exceeding 130°F, 54°C or a scald injury will occur! When higher water temperatures are required for appliances such as a dishwasher, a mixing valve or some other tempering means must be installed. Households with small children may require water temperatures less than 120°F, 49°C. Local codes must be complied with!

Table 6 - Recommend System Temperatures

	Hi	Dif	RES
System	°F, °C	°F, °C	°F, °C
Finned Tube Baseboard	190, 88	20, 11.7	85, 29
Cast Iron Radiators	150, 66	20, 11.7	85, 29
Radiant	130, 54	20, 11.7	85, 29

Outdoor Sensor (10K)

The outdoor sensor should be installed to take advantage of the energy saving features of the Sentry Controller. Install the sensor on the north, or coldest side of the building out of direct sun. It must be at least 10 ft, 3 m from the vent terminal or other source of heat.