12
Sentinel
u
TEMP
ACTIVE
Indicates that the
Fuel Smart HydroStat control is powered
and that the temperature function is
active.
v
TEMP
HIGH TEMP
Illuminates
when the boiler water temperature reach-
es the high limit setting. It will remain lit
until the water temperature falls 5.5°C
(10°F) (see High Limit Differential on page
4). 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.
x
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.
y
ECONOMY
ACTIVE
Indicates that the Thermal Targeting func-
tion is active and the Fuel Smart HydroStat will reduce boiler tem-
perature to conserve fuel. The Economy feature is activated using
the ECONOMY dial. (See “How Thermal Targeting Works” on page
4 for more information).
z
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 temperature, the
LED illuminates and the burner will shut
down. The boiler water will continue to cir-
culate and heat the house as long as the
thermostat call continues. The LED will
stay lit until the boiler temperature 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 regu-
larly during normal boiler operation.
{
TEST/SETTINGS
Button
To Test Low Water Cut-Off
: Press and hold the Test/Settings button
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 functionality (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 WA
TER
ACTIVE
TARGET
TARGET SET
TINGS
u v w x y z {
TEMP LWCO ECONOMY
LED LEGEND and TEST/SETTINGS BUTTON