Install Instructions
4
The Knight XL - How it works...
1. Stainless steel heat exchanger
Allows system water to ow through specially designed
coils for maximum heat transfer, while providing protection
against ue gas corrosion. e coils are encased in a jacket that
contains the combustion process.
2. Combustion chamber access cover
Allows access to the combustion side of the heat exchanger
coils.
3. Blower
e blower pulls in air and gas through the venturi.
Air and gas mix inside the blower and are pushed into the
burner, where they burn inside the combustion chamber.
4. Gas valve
e gas valve senses the negative pressure created by the
blower, allowing gas to ow only if the gas valve is powered and
combustion air is owing.
5. Venturi
e venturi controls air and gas ow into the burner.
6. Flue gas sensor (limit rated)
is sensor monitors the ue gas exit temperature. e
control module will modulate and shut down the boiler if the
ue gas temperature gets too hot. is protects the ue pipe from
overheating.
7. Boiler outlet temperature sensor (housed with the
high limit sensor)
is sensor monitors boiler outlet water temperature (system
supply). If selected as the controlling sensor, the control
module adjusts boiler ring rate so the outlet temperature is
correct.
8. Boiler inlet temperature sensor
is sensor monitors return water temperature (system
return). If selected as the controlling sensor, the control
module adjusts the boiler ring rate so the inlet temperature is
correct.
9. Temperature and pressure gauge ( eld installed, not
shown)
Monitors the outlet temperature of the boiler as well as the
system water pressure.
10. Electronic display
Digital controls with SMART TOUCH screen technology, full
color display, and an 7" user interface screen.
11. Flue pipe adapter
Allows for the connection of the PVC vent pipe system to the
boiler.
12. Burner (not shown)
Made with metal ber and stainless steel construction, the
burner uses pre-mixed air and gas and provides a wide range of
ring rates.
13. Water outlet (system supply)
A 2" (Models 400 - 800) or 2.5" (Model 1000) water connection
that supplies hot water to the system.
14. Water inlet (system return)
A 2" (Models 400 - 800) or 2.5" (Model 1000) copper water
connection that returns water from the system to the heat
exchanger.
15. Gas connection pipe
readed pipe connection of 1" or 1 1/4" (depending on the
model). is pipe should be connected to the incoming gas
supply for the purpose of delivering gas to the boiler.
16. SMART TOUCH Control Module
e SMART TOUCH Control responds to internal and
external signals and controls the blower, gas valve, and pumps
to meet the heating demand.
17. Air intake adapter
Allows for the connection of the PVC air intake pipe to the
boiler.
18. High voltage junction box
e junction box contains the connection points for the line
voltage power and all pumps.
19. Boiler drain port
Location from which the heat exchanger can be drained.
20. Low voltage connection board
e connection board is used to connect external low voltage
devices.
21. Low voltage wiring connections (knockouts)
Conduit connection points for the low voltage connection
board.
22. Condensate drain connection
Connects the condensate drain line to a 1/2" PVC connection.
23. Access cover - front
Provides access to the gas train and the heat exchanger.
24. Ignition electrode
Provides direct spark for igniting the burner.
25. Flame inspection window
e quartz glass window provides a view of the burner surface
and ame.
26. Relief valve
Protects the heat exchanger from an over pressure condition.
e relief valve provided with the unit is set at 50 PSI.
27. Flame sensor
Used by the control module to detect the presence of burner
ame.
28. Line voltage wiring connections (knockouts)
Conduit connection points for the high voltage junction box.
29. Top panel
Removable panel to gain access to the internal components.
30. Power switch
Turns 120 VAC ON/OFF to the boiler.
31. Air box
e air box houses the combustion air lter.
32. Air pressure switch (400 and 800 models only)
e air pressure switch detects blocked ue/inlet conditions.
break the control circuit, shutting the boiler down.
33. Pump relays
e pump relay is used to connect the boiler, system and
DHW pumps.
34. Transformer
e transformer provides 24V power to the integrated control.
35. High limit sensor (housed with the outlet temperature
sensor)
Device that monitors the outlet water temperature. If the
temperature exceeds its setting, the integrated control will break
the control circuit, shutting the boiler down.
36. Air Filter (not shown)
e air lter prevents dirt and debris from entering the burner.
37. Flow Switch
e ow switch is a safety device that ensures ow through
the heat exchanger during operation. is appliance is low
mass and should never be operated without ow. e ow
switch makes contact when ow is detected and allows the unit
to operate. If ow is discontinued during oepration for any
reason, the ow switch will break the control circuit and the
unit will shut down.
Installation & Operation Manual