The Noble Fire Tube - How It Works - Lochinvar NOBLE NKB 199 Installation & Service Manual

The Noble Fire Tube - How it works...

1. Heat exchanger
Allows system water to flow through specially designed
coils for maximum heat transfer, while providing
protection against flue gas corrosion.
encased in a jacket that contains the combustion process.
2. Blower
The blower pulls in air and gas through the venturi (item
5). Air and gas mix inside the blower and are pushed into the
burner, where they burn inside the combustion chamber.
3. Gas valve
The gas valve senses the negative pressure created by the
blower, allowing gas to flow only if the gas valve is
powered and combustion air is flowing.
4. Venturi
The venturi controls air and gas flow into the burner.
5. Flue gas sensor (limit rated)
This sensor monitors the flue gas exit temperature. The control
module will modulate and shut down the boiler if flue gas
temperature gets too hot. This protects the flue pipe from
overheating.
6. Boiler outlet temperature sensor (limit rated)
This sensor monitors boiler outlet water temperature (system
supply). The control module will adjust boiler firing rate so the
outlet temperature is correct.
7. Boiler inlet temperature sensor
This sensor monitors return water temperature (system
return).
8. Temperature and pressure gauge (field installed, not
shown)
Monitors the outlet temperature of the boiler as well as the
system water pressure.
9. Electronic LCD display
The electronic display consists of five (5) buttons, and a liquid
crystal display. The display is used to make adjustments and
read boiler status.
10. Flue pipe adapter
Allows for the connection of the vent pipe system to the
boiler.
11. Burner (not shown)
Made with metal fiber and stainless steel construction,
the burner uses pre-mixed air and gas and provides a
wide range of firing rates.
12. Boiler water outlet
The boiler water outlet is the boiler water connection for water
leaving the boiler and entering the system.
13. Domestic Hot Water (DHW) water outlet (Combi Only)
The DHW water outlet is the water connection for domestic water
leaving the boiler and entering the system.
14. Boiler water inlet
The boiler water inlet is the boiler water connection for water
entering the boiler from the system.
15. Domestic Hot Water (DHW) water inlet (Combi Only)
The DHW water inlet is the water connection for domestic water
entering the boiler from the system.
16. Gas connection pipe
Threaded pipe connection of 1/2".
connected to the incoming gas supply for the purpose of
delivering gas to the boiler.
4
17. Boiler control module
The coils are
18. Air intake adapter
19. High voltage junction box
20. Low voltage connection board
21. Low voltage wiring connections
22. Condensate drain connection
23. Front access cover
24. Ignition / flame sense electrode
25. Flame inspection window
26. Relief valve
27. Line voltage wiring connections (inside junction box)
28. Air pressure switch
29. Transformer
30. Pump (Combi Only)
31. Diverter valve (Combi Only)
32. DHW Flow switch (Combi Only)
33. Domestic Hot Water (DHW) sensor (Combi Only)
34. Condensate trap
This pipe should be
35. Water pressure switch
Installation & Service Manual
™
F I R E T U B E
The boiler control responds to internal and external signals
and controls the blower, gas valve, and pumps to meet the
demand.
Allows for the connection of the air intake pipe to
the boiler.
The junction box contains the connection points for the line
voltage power and all pumps.
The connection board is used to connect external low voltage
devices.
Conduit connection points
connection board.
The condensate drain connection provides a connection
point to install a condensate drain line.
Provides access to all internal components.
Used by the control module to detect the presence of burner
flame.
The quartz glass window provides a view of the burner
surface and flame.
Protects the heat exchanger from an over pressure condition.
The relief valve provided with the unit is set at 50 psi on Combi
models and 30 psi on Boiler models.
Conduit connection points for the high voltage junction box.
The air pressure switch detects blocked conditions.
The transformer provides 24V power to the integrated control.
Provides flow through the unit for space heating and domestic
water applications. Serves as the boiler and DHW pump.
Diverts boiler water from the heating loop to the DHW heat
exchanger.
The DHW flow switch detects a DHW draw and signals the
boiler to fire.
This sensor monitors
The control module will adjust boiler firing rate so the
DHW temperature is correct.
The condensate trap is sized for a 3/4" PVC outlet connection
pipe. Note: The Noble Combi trap is factory installed
whereas the Noble Boiler trap is factory supplied, but field
installed.
The water pressure switch detects low water pressure
conditions.
for the low voltage
DHW water temperature.