Install Instructions

43
VI: OPERATING (continued)
TABLE 11: EXTERNAL LOW LIMIT,
PARAMETER = 
Call for Heat Circulator Status
T-T
Input
ZR
Input
C1
Output
ZC
Output
off off off on
on off on on
on on off off
off on off off
Call for Heat Circulator Status
T-T
Input
ZR
Input
C1
Output
ZC
Output
off off off off
on off on off
on on on on
off on off on
TABLE 10: ZONE REqUEST, PARAMETER =
iii. External Low Limit, Parameter  = 
The Cold Start Boiler Control is capable of
functioning as a warm start control when
external limit control is installed that closes
a contact when boiler water temperature falls
below a setpoint. When an external limit
contact closes (boiler water is cold) the boiler is
started and the "ZC" and "C1" output terminals
are de-energized. When the "ZR" terminal
is de-energized (boiler water temperature is
above setpoint) the call for heat is ended and
the "C1" terminal is released to operation and
the "ZC" terminal is energized. An External
Low Limit Request is detected by sensing a
voltage on the "ZR" terminal. The Warm Start
Boiler Control does not have the External Low
Limit Option. Refer to Table 11.
7. HydroStat 3250 Plus Sequence of Operation
a. Refer to the HydroStat Instructions
(P/N 104145-01) for all operational instructions.
2. Refer to the "IMPORTANT" notice below.
B. STEAM BOILERS SEQUENCE OF OPERATION
Upon a thermostat call for heat, when provided, the Oil
Primary Control is energized when the steam pressure is
below the L404F Pressure Limit and water level is above
the Low Water Cut-Off. When energized the Oil Primary
Control starts the burner as follows; blower is started
and operates for a pre-purge time; spark is energized and
fuel valve is opened for ignition trail time; the fuel valve
remains open when ame is proven. The burner res until
the thermostat is satised or the Pressure Limit setting
is reached. The Oil Primary Control stops the burner
by closing the fuel valve and operating the blower for
post-purge time. Upon a drop in pressure, steam pressure
below the L404F Pressure Limit, the burner will re-start
if the thermostat is still calling for heat. When there is a
tankless heater included and there is no demand for heat,
the L4006A operating control will maintain the boiler water
temperature at the selected setting for proper operation of
the domestic water heater.
The probe low water cut-off will shut down the burner
after a 10 second delay, if the water level in the boiler
drops below the probe level. If the water level is too low
the burner will not be allowed to restart. The low water
cut-off will reset and restart the burner with a call for heat
30 seconds after the water is returned to its normal level.
On burner start, if the CAD cell does not see ame within
approximately 15 seconds, primary control will shut down
the burner and enter into a lockout mode. A lockout is
reset by pressing the reset button located on the primary
control. If the ame is lost while the burner is ring, the
primary control shuts down the burner, enters a 60 second
recycle delay, and repeats the ignition sequence. If after
three (3) trials for ignition, ame is not detected, primary
control will enter into restricted mode. Restricted mode
is reset by holding down the reset button for 15 seconds.
IMPORTANT
This boiler is equipped with a feature that saves energy by reducing the boiler water temperature as the heating load
decreases. This feature is equipped with an override which is provided primarily to prevent the use of an external energy
management system that serves the same function. THIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST ONE
OF THE FOLLOWING CONDITIONS IS TRUE:
• An external energy management system is installed that reduces the boiler water
temperature as the heating load decreases.
• This boiler is not used for any space heating.
• This boiler is part of a modular or multiple boiler system having a total input of
300,000 BTU/HR or greater.
• This boiler is equipped with a tankless coil.