Endurance | Page 21 |
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jacket, remove the four (4) long screws that secure the top and bottom pans. Remove the air vent and the top pan. Remove the insulation retainer and the coil cover insulation. Clean the boiler coil with a wire brush and vacuum debris from the combustion chamber (avoid hitting the ignitor or the flame sensor with the brush or vacuum hose because they are fragile).
After cleaning, assemble the parts in the reverse order, open isolation valves and bleed air from the boiler and the system. Follow the lighting instructions and start the boiler. Check operation.
seconds while the [MC] indicates alternately 
and the current boiler outlet temperature.
2.Following the prepurge cycle the ignitor will heat for 10 seconds while the blower continues to operate.
3.The gas valve will then be energized (green ‘GV’ LED located on the PCB next to the display will light) and open, gas will flow and ignition will occur.
SECTION 8
Servicing.
8A. Sequence of Operation
Figures 22 and 23 depict the flow paths and temperature sensor locations for the space heating, EDP/EDN, and the combined space heating and domestic water heating, EBP, appliances.
The model EDP/EDN modulating boilers are cold start boilers that will start only on a call for heat from a room thermostat or zone control contact. During normal operation the Message Center [MC] LED display will indicate ‘ON’ while awaiting a call for heat. On a call for heat the following sequence will occur.
1.(a) The internal pump will start.
(b) After 5 seconds the blower prepurge cycle will start and operate for approximately 6
Figure 27. EDP/EDN Flow Schematic.
Figure 28. EBP Flow Schematic.
