Dunkirk DXL Series - Manual (Page 23)

23
17 - OPERATING THE BOILER - SYSTEM START-UP
System Start-up
At initial start-up, with Economy feature active, control
establishes 145°F target temperature. To test the high
limit shut-off function, Economy Dial must be turned to
OFF. Once tested, restore the Economy setting. If heating
demand is high, target will increase over time to satisfy
heat load. to reduce potential for condensing, control
will allow boiler to heat to 120°F prior to energizing the
circulator.
How Thermal Targeting Works
Thermal targeting technology analyzes thermostat activity
and continually evaluates how much heat the house
requires. When it is very cold outside, heat demand is
high and Fuel Smart HydroStat will raise boiler's target
temperature to provide needed heat to the home. When
outside temperature is milder, heat demand is lower. During
these periods, Fuel smart HydroStat will lower boiler's
target temperature saving fuel while continuing to provide
comfort to the house.
LED Legend

LOW WATER
Illuminates if boiler is in a low water condition. Control will
prevent burner operation during this condition.
NOTICE
System must be checked by a qualifi ed heating
professional prior to resuming operation.
WARNING
Burn and scald hazard. Do not add water until boiler
has fully cooled. Failure to follow these instructions
could result in death or serious injury.
!

T-STAT
Illuminates whenever there is a call for heat from any
thermostat, zone device or indirect.

TARGET/HI LIMIT
Illuminates when boiler temperature has reached target
temperature or high limit setting. When economy feature
is active, the control utilizes thermal targeting technology
to operate boiler at reduced target temperatures (during
off-peak demand) or at high limit setting (during peak
demand). When boiler water temperature reaches the
target or high limit temperature, LED illuminates and
burner shuts down. Boil water continues to circulate and
heat the house as long as thermostat call continues.
The LED will stay lit until boiler temperature drops to
predetermined differential. The LED illuminates regularly
during normal operation.

BURNER

Illuminates whenever the burner is running (B1 is
powered).
Test/Settings Button
To test low water cut-off: Press and hold TEST/SETTINGS
button for 5 seconds. Display will read LCO.
The red Low Water light should illuminate and burner circuit
(B1 and B2) should energize.
To View Current Settings: Press and release the TEST/
SETTINGS button in short intervals to sequentially display
following settings:
The display will return to boiler temperature (default) if
TEST/SETTINGS button is not pressed for 5 seconds.