Designer Guide

36
LOCHINVAR, LLC
300 MADDOX SIMPSON PKWY
LEBANON, TN 37090
www.lochinvar.com
Designer’s Guide / Knight XL Boiler
The Vent is designed to remove trapped air from the heat
exchanger coils.
18. Air intake adapter
The adapter allows for the connection of the air intake pipe to the boiler.
19. High voltage junction box
The junction box contains the connection points for the line voltage power and all pumps.
20. Boiler drain port
The port is the location from which the heat exchanger can be drained.
21. Low voltage connection board
The connection board is used to connect external low voltage devices.
22. Low voltage wiring connections (knockouts)
Conduit connection points for the low voltage connection board.
23. Condensate drain connection
It connects the condensate drain line to a 1/2" PVC union.
24. Access cover - front
The cover provides access to the gas train and the heat exchanger.
25. Ignition electrode
The electrode provides direct spark for igniting the burner.
26. Flame inspection window
The quartz glass window provides a view of the burner surface and flame.
27. Gas shutoff valve
Manual valve used to isolate the gas valve from the gas supply.
28. High limit
The limit monitors the outlet water temperature. If the temperature exceeds its setting, it
will break the control circuit, shutting the boiler down.
29. Relief valve
Protects the heat exchanger from an over pressure condition. The relief valve will be set
at 50 PSI.
30. Flame sensor
Used by the control module to detect the presence of burner flame.
31. Line voltage wiring connections (knockouts)
Conduit connection points for the high voltage junction box.
32. Top panel
It is a removable panel to gain access to the internal components.
33. Power switch
The switch turns 120 VAC ON/OFF to the boiler.
34. Leveling legs
The legs are used to allow the heat exchanger to be leveled. This is needed for the
proper draining of the condensate from the combustion chamber.
35. Air shroud (Model 501 only)
The air shroud controls air and gas flow into the burner.
36. Air pressure switch
The air pressure switch detects blocked flue/vent conditions.
37. Pump relay board
The pump relay board is used to connect the boiler, system and DHW pumps.