15
Sentry
u
TEMP
ACTIVE
Indicates that the
Fuel Smart HydroStat control is pow-
ered and that the temperature function
is active.
v
TEMP
HIGH TEMP
Illuminates
when the boiler water temperature
reaches the high limit setting. It will
remain lit until the water temperature falls
10° (see High Limit Differential on page
11). The Fuel Smart HydroStat prevents
burner operation while this LED is on.
w
LWCO
ACTIVE
Indicates that the low water cut-off (LWCO)
function of the Fuel Smart HydroStat is active. When the
control is installed with a Hydrolevel Electro-Well, this LED will be
on at all times when the control is powered.
IMPORTANT:
If the control is installed with a well other than the
Electro-Well, this LED will not illuminate indicating that the control
is not providing low water cut-off functionality.
❹
LWCO
LOW WATER
Illuminates if the boiler is in a low water
condition. The Fuel Smart HydroStat will prevent burner operation
during this condition.
IMPORTANT:
The system must be checked
by a qualified heating professional prior to resuming operation.
WARNING: DO NOT ADD WATER UNTIL THE BOILER
HAS FULLY COOLED.
❺
ECONOMY
ACTIVE
Indicates that the Thermal Targeting
function is active and the Fuel Smart HydroStat will reduce boiler
temperature to conserve fuel. The Economy feature is activated
using the ECONOMY dial. (See “How Thermal Targeting Works”
on page 4 for more information).
➏
ECONOMY
TARGET
When the Economy feature is active,
the Fuel Smart HydroStat continually sets target temperatures
below the high limit setting to maximize fuel efficiency. When the
boiler water reaches the target tempera-
ture, the LED illuminates and the burner
will shut down. The boiler water will con-
tinue to circulate and heat the house as
long as the thermostat call continues.
The LED will stay lit until the boiler tem-
perature drops to the differential set point
(see Target Temp Differential on page 4)
at which point the boiler will be allowed to
fire again. NOTE: This LED illuminates
regularly during normal boiler operation.
❼
TEST/SETTINGS
Button
To Test Low Water Cut-Off
: Press and hold the Test/Settings but-
ton for 5 seconds. The display will read LCO.
LWCO TEST
LCO
The red Low Water light should illuminate and the burner circuit
(B1 and B2) should de-energize. NOTE: The control must be
installed with a Hydrolevel Electro-Well for low water cut-off func-
tionality (see page 2 for more details).
To View Current Settings: Press and release the Test/Settings Button
in short intervals to sequentially display the following settings:
HIGH LIMIT SETTING
HL
q
LOW LIMIT SETTING
LL
q
ECONOMY SETTING
ECO
q
CURRENT TARGET TEMPERATURE
ooo
q
PRE-PURGE SETTING
Pur
The display will return to boiler temperature (default) if
Test/Settings Button in not pressed for 5 seconds.
ACTIVE
HI TEMP
ACTIVE
LOW W
A
TER
ACTIVE
TARGET
TARGET SETTINGS
❶ ❷ ❸ ❹ ❺ ❻ ❼
TEMP LWCO ECONOMY
LED LEGEND and TEST/SETTINGS BUTTON
At initial start up, with the Economy Feature active, the control
establishes a 145°F target temperature. To test the high limit
shut-off function, the Economy Dial must be turned to OFF.
Once tested, restore the Economy setting. If the heating
demand is high, the target will increase over time to satisfy the
heat load.
Thermal Targeting technology analyzes thermostat activity and
continually evaluate how much heat the house requires. When
it is very cold outside, the heat demand is high and the Fuel
Smart HydroStat will raise the boiler s Target temperature to
provide needed heat to the home. When the outside tempera-
ture is milder, the heat demand is lower. During these periods,
the Fuel Smart HydroStat will lower the boiler s Target temper-
ature – saving fuel – while continuing to provide comfort to the
house.
SYSTEM START-UP
HOW THERMAL TARGETING WORKS
NOTE:
Smart DHW Priority : During a call from indirect water heater, the control will de-energize the circulator contacts (C1/C2) to heat
only the indirect tank ensuring an adequate supply of domestic hot water. The control will re-energize the circuator when the
indirect tank is satisfied or if the boiler temperature reaches 170˚F. If the indirect call continues for 45 minutes, the control will
overide the priority function energizing the circulator to provide space heating.
Summary of Contents for S-34
Page 10: ...10 Sentry Figure 9 Single zone with indirect water heater DHW Priority using R882A B relay...
Page 18: ...18 Sentry Figure 11 Zoning with circulators optional indirect DHW tank...
Page 19: ...19 Sentry Figure 12 Zoning with zone valves optional indirect DHW tank...
Page 27: ...27 Sentry...