Page 35
Figure 27. The Test (Reset) Button
7
TEMP ACTIVE
Indicates that the Fuel Smart
HydroStat control is powered and that the temperature
function is active.
TEMP HI TEMP
Illuminates when the boiler water
temperature reaches the high limit setting. It will remain lit
until the water temperature falls 10°. The Fuel Smart
HydroStat prevents burner operation while this LED is on.
See Differential explanation
LWCO ACTIVE
Indicates that the low water cut-off
(LWCO) function of the control is active.
The JX comes standard with an Electro-Well which works
as both a standard well and a Low Water Cut-off probe.
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.
LWCO LOW WATER
Indicates that the boiler is in a
low water condition. The control will prevent burner
operation during this condition. If the LOW WATER light is
blinking, the control has been programmed to provide lock-
out protection in the event a low water condition is detected
See Manual Reset Low Water Cut-Off
IMPORTANT: The system must be checked by a qualified
heating professional prior to resuming operation.
WARNING: ALLOW THE BOILER TO FULLY COOL
BEFORE ADDING WATER.
ECONOMY ACTIVE
Indicates that the Thermal
Targeting function is active and the control will
reduce boiler temperature to conserve fuel. The Economy
feature is activated using the ECONOMY dial. (See “How
Thermal Targeting Works”
ECONOMY TARGET
When the Economy feature is
active, the control 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 circulate and heat the
house as long as the thermostat call continues. The LED will
stay lit until the boiler temperature drops below the differential
set point at which point the boiler will be allowed to fire again.
See Differential explanation
NOTE: This LED illuminates regularly 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
0
The red Low Water light should illuminate and the burner
circuit should de-energize. NOTE: The control must be
installed with a Electro-Well for low water cut-off
functionality.
To View Current Settings: Press and release the
Test/Settings Button in short intervals to sequentially display
the following settings:
HIGH LIMIT SETTING
HL
LOW LIMIT SETTING
LL
ECONOMY SETTING
ECO
0
FLAME CURRENT
FLA
CURRENT TARGET TEMPERATURE
ooo
The display will return to boiler temperature (default) if
Test/Settings Button in not pressed for 5 seconds.
NOTE: Flame Current reading will remain in the display for
30 seconds to allow for pilot adjustment
LED LEGEND and TEST/SETTINGS BUTTON
8.D TEST / SETTINGS Button
- To Test Low Water Cut-Off: Press and hold the Test/Settings button for 5 seconds. The display will read LCO.
The red Low Water light should illuminate and the burner circuit
should de-energize.
To View Current Settings: Press and release the Test/Settings
Button in short intervals to sequentially display the following
settings:
8.E Temperature and Pressure Gauge
The Temperature and Pressure gauge is viewable just above the
Digital Dashboard. The pressure is sensed at the top front section
of the inlet/outlet header. The temperature is sensed at the outlet
pipe.
11
OPTIONAL FEATURES continued
NOTE: If the HydroStat is factory-equipped on a boiler, some options may be set differently from the default settings.
SEE PAGE 4 FOR ADDITIONAL SETTINGS
Dial
Setting
Feature
Options
Description
Default
Setting
2
Fahrenheit or Celsius
F
c
Degrees Fahrenheit
Degrees Celsius
F
3
LWCO Manual or
Automatic Reset
A
b
Automatic Reset
Manual Reset
A
4
Not available
on this control
6
Not available
on this control
7
8
Low Water Cut-Off
Function
on
OFF
Low Water Cut-Off ON
Low Water Cut-Off OFF
on
9
High Limit
Differential
10
10
20
30
10° Differential
20° Differential
30° Differential
dEF
Restore Factory
Defaults
Y
n
Restore Defaults
Do Not Restore Defaults
n
10
11
OPTIONAL FEATURES continued
NOTE: If the HydroStat is factory-equipped on a boiler, some options may be set differently from the default settings.
SEE PAGE 4 FOR ADDITIONAL SETTINGS
Dial
Setting
Feature
Options
Description
Default
Setting
2
Fahrenheit or Celsius
F
c
Degrees Fahrenheit
Degrees Celsius
F
3
LWCO Manual or
Automatic Reset
A
b
Automatic Reset
Manual Reset
A
4
Not available
on this control
6
Not available
on this control
7
8
Low Water Cut-Off
Function
on
OFF
Low Water Cut-Off ON
Low Water Cut-Off OFF
on
9
High Limit
Differential
10
10
20
30
10° Differential
20° Differential
30° Differential
dEF
Restore Factory
Defaults
Y
n
Restore Defaults
Do Not Restore Defaults
n
10
Table 9. Factory Defaults
M
INI-
T
HERM
JX
Residential Boilers
®
