Sequence Of Operation - Slant/Fin Q3-4 Supplemental Instructions

Riello 40BF
1.
Room temperature drops, thermostat calls for heat.
2.
Pre-purge begins, lasting 5 to 15 seconds. BVS is
energized.
3.
If flue is clear, pressure switch allows ignition sequence
to continue.
4.
Oil Solenoid opens allowing oil to reach burner
electrodes. Burner ignition begins.
5.
Cad cell detects light from combustion, disconnects
primary control safety circuit, allowing combustion to
continue.
6.
After 15 to 45 seconds (depending on primary control
characteristics), electric spark across electrode tips
stops, combustion continues.
7.
Boiler continues to operate and reaches "steady state",
the point at which the system temperature stabilizes.
8.
Room temperature rises, thermostat is satisfied,
heating contacts open.
9.
Oil solenoid valve closes, combustion stops, burner
motor remains on to complete post purge cycle. Post
purge time can be 10 seconds to 5 minutes depending
on settings. Factory default is 30 seconds. Timing can
be changed by rotating dial on Riello burner fan-off
timer control board.
10.
Boiler remains idle until next call for heat.

SEQUENCE OF OPERATION

Figure 9 - Air Shutter Setting
8
P/N 473921000