Use and Care Manual

26
V: OPERATING
A. WATER BOILERS SEQUENCE OF
OPERATION
1. Water Boilers Without Tankless Heaters (Cold
Start), Sequence Of Operation:
a. The RRO Boiler is equipped with an Intelligent
Oil Boiler Control (Cold Start Boiler Control).
The boiler control replaces the traditional
electronic aquastat and circulator relays and adds
energy saving thermal purge features. Energy is
saved by starting the circulator and delaying the
burner start when there is residual heat available
in the boiler.
b. The boiler’s sequence of operation is shown as
Status Codes on Boiler Control display. See
Table 6 and Figure 18.
c. When the thermostat calls for heat the boiler
control starts the system circulator and the
thermal purge (circulator pre-purge time) begins.
If the time is completed or boiler temperature is
less than the Start Temperature (140 F default)
the start sequence continues by energizing the
oil primary to operate the following sequence:
blower is started and operates for pre-purge
time; spark is energized and fuel valve is opened
for ignition trial time; burner res until the
thermostat is satised.
d. If the thermostat is not satised and the
Operating Setpoint (SP) is reached the system
circulator will continue to operate and the burner
will stop. When the boiler water temperature
drops below the setpoint less the differential
setting the burner will restart.
e. After the thermostat is satised the burner and
circulator are stopped.
f. When an indirect water heater aquastat call for
heat is wired to the “ZR” terminal the Boiler
Control starts a domestic hot water circulator
connected to the “ZC” terminal and when the
boiler temperature is less than Operating Setpoint
(SP), the boiler control energizes the oil primary
to turn on the burner without circulator pre-purge
delay.
g. 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.
Figure 18: Intelligent Oil Boiler Control
2. Water Boilers with Tankless Heaters (Warm
Start), Sequence Of Operation:
a. The RRO Boiler is equipped with a Warm Start
Intelligent Oil Boiler Control (Warm Start
Boiler Control). The Warm Start Boiler Control
replaces the traditional high and low limit
aquastat and circulator relays.
b. The boiler’s sequence of operation is shown as
Status Codes on Boiler Control display. See
Table 6 and Figure 18.
c. When the thermostat calls for heat the boiler
control starts the system circulator and the
start sequence continues by energizing the oil
primary to operate the following sequence:
blower is started and operates for pre-purge
time; spark is energized and fuel valve is
opened for ignition trial time; burner res until
the thermostat is satised. Optionally, the
thermal purge (circulator pre-purge time) maybe
added adjusting the Circulator Pre-purge time
parameter. This feature saves energy by starting
the circulator and delaying the burner start when
there is residual heat available in the boiler .
Status Codes Displayed in  Mode
 Status Description

Standby
(burner off,
pump off)
No call for heat detected

Standby
(burner off,
pump on)
Either condition is true:
a. Call for heat detected and boiler
temperature higher than operating
setpoint.
b. Call for heat detected and boiler
temperature higher than 140 F and
Pump Pre-Purge Time has not
expired.
 Running
The burner runs until the call for heat is
satised.
 Self Test Control internal checking
TABLE 6: SEqUENCE OF OPERATION