Burnham Independence Operating And Service Instructions page 47

P.
Water Boiler with Intermittent Ignition (HSP) and
Intermittent Circulation. See Figure 43.
1. Normal Operation
a. Thermostat calls for heat.
b. Vent Damper (if used) opens as stated in Vent
Damper Sequence of Operation.
c. Gas Valve is energized. Igniter is energized and
Pilot Valve opens to ignite Pilot Burner.
d. Sensor proves presence of pilot flame and Gas
Valve de-energizes igniter. Main Valve opens
and ignites Main Burners.*
e. After Thermostat is satisfied Gas Valve is de-
energized, extinguishing pilot and main flame.
Vent Damper (if used) closes.
2. Safety Shutdown
a. Limit: Automatically interrupts main burner
operation when water temperature exceeds set
point. Maximum allowable temperature is 250°F.
Normal operation resumes when water
temperature falls below set point.
b. Blocked Vent Switch. Automatically interrupts
main burner operation when excessive vent
system blockage occurs. Control is a multiple
use device. If blocked vent switch is activated do
not attempt to place boiler in operation. Correct
source of blockage and reset blocked vent
switch.
c. Flame Roll-out Switch. Automatically interrupts
boiler operation when flames or excessive heat
are present in vestibule. Control is single use
device. If flame roll-out switch is activated do
not attempt to place boiler in operation. Correct
source of blockage and replace flame roll-out
switch.
d. Sensor: senses pilot flame and causes Gas Valve
to interrupt main burner and pilot burner gas
flow should pilot burner flame extinguish.
For Hot Surface to Pilot Trouble Shooting Guide, see
Page 75.
•
*
SV9500 and SV9600 Gas Valves:
The igniter and pilot gas valve will stay
energized until either the pilot lights or the call
for heat ends.
•
SV9501 and SV9601 Gas Valves:
If the pilot fails to light after a 90 second trial for
ignition, the igniter will be de-energized and the
pilot gas valve will close. After a 5 minute delay,
the igniter will be re-energized and the pilot gas
valve will re-open. This continuous retry cycle
will end either when the pilot lights or the call
for heat ends.
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