Burnham SERIES 2 manual Pilot

SEQUENCE OF OPERATION

NORMAL OPERATION

1.When THERMOSTAT calls for heat, the VENT DAMPER is opened (see Paragraphs 17A through 17D). When the damper blade reaches the fully open position, the GAS VALVE powers the igniter circuit and opens the pilot valve.

2.The sensing circuit between the Q3450 or Q3480 pilot and the GAS VALVE proves presence of pilot flame.*

3.The GAS VALVE de-energizes the igniter and opens the main valve, allowing main gas to flow and ignition of main burners.

4.On Boilers equipped with Circulators that are wired to run continuously and, where condensation of flue gas is encountered in boiler flues, a REVERSE ACTING CIRCULATOR CONTROL should be installed to stop the Circulator before the Boiler Water Temperature drops to that at which flue gas condensation may occur.

5.The Burners will operate until the THERMOSTAT is satisfied.

6.After the THERMOSTAT is satisfied the GAS VALVE will be de-energized. The Main Burners and Pilot Burner will be extinguished. If Boiler is equipped with circulator, Circulator will continue to run. The VENT DAMPER will close (see Paragraph 17E).

SAFETY SHUTDOWN

1.High Limit Switch

In the event excessive boiler water temperature is developed, the High Limit will open, interrupting power to the IGNITION MODULE and the DUAL COMBINATION GAS VALVE. Main Burners and Pilot Burner will be extinguished immediately and the vent damper will close. Normal operation will be resumed when the Boiler Water Temperature drops to a point where the High Limit Switch closes.

2.Blocked Vent Switch

In the event excessive blockage in the vent system is developed the blocked vent switch will open interrupt- ing power to the ignition module and dual combina- tion gas valve. Main burners and pilot burner will be extinguished immediately and the vent damper will close. The source of blockage must be corrected by trained and skilled personnel from a qualified service agency before resetting switch.

3.Flame Rollout Switch

In the event excessive blockage in the boiler section flue passageways is developed the flame rollout switch will open interrupting power to the ignition module and the dual combination gas valve. Main burners and pilot burner will be extinguished immediately and the vent damper will close. If the flame rollout switch is activated do not attempt to place the boiler in opera- tion. The source of blockage must be corrected and the flame rollout switch replaced by trained and skilled personnel from a qualified service agency.

4.Pilot

A.Any pilot failure on the Q3450 or Q3480 pilot will close the main gas valve and energize the igniter.

B.If the igniter breaks or becomes disconnected, the pilot valve coil loses power, closing the pilot valve.

5.For TROUBLE SHOOTING GUIDE, see Figure 28.

*· 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.

17