Lochinvar 801, 400 operation manual Knight XL How it works, Stainless steel heat exchanger

Installation & Operation Manual

The Knight XL - How it works...

1.Stainless steel heat exchanger

Allows system water to flow through specially designed coils for maximum heat transfer, while providing protection against flue gas corrosion. The 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

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.

4.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.

5.Venturi

The venturi controls air and gas flow into the burner.

19.High voltage junction box

The junction box contains the connection points for the line voltage power and all pumps.

20.Boiler drain port

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

Connects the condensate drain line to a 1/2" PVC union.

24.Access cover - front

Provides access to the gas train and the heat exchanger.

6.Flue gas sensor (limit rated)

This sensor monitors the flue gas exit temperature. The control module will modulate and shut down the boiler if the flue gas temperature gets too hot. This protects the flue pipe from overheating.

7.Boiler outlet temperature sensor (housed with the high limit sensor)

This sensor monitors boiler outlet water temperature (system supply). If selected as the controlling sensor, the control module adjusts boiler firing rate so the outlet temperature is correct.

8.Boiler inlet temperature sensor

This sensor monitors return water temperature (system return). If selected as the controlling sensor, the control module adjusts the boiler firing rate so the inlet temperature is correct.

25.Ignition 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.Relief valve

Protects the heat exchanger from an over pressure condition. The relief valve provided with the unit is set at 50 PSI.

29.Flame sensor

Used by the control module to detect the presence of burner flame.

9.Temperature and pressure gauge (field installed, not shown)

Monitors the outlet temperature of the boiler as well as the system water pressure.

10.Electronic LCD display

The electronic display consists of 4 buttons, a navigation dial and a multiple line liquid crystal display.

11.Flue pipe adapter

Allows for the connection of the PVC vent pipe system to the boiler.

12.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.

13.Water outlet (system supply)

A 1-1/2" or 2" NPT (depending on the model) water connection that supplies hot water to the system.

14.Water inlet (system return)

A 1-1/2" or 2" NPT (depending on the model) water connection that returns water from the system to the heat exchanger.

15.Gas connection pipe

Threaded pipe connection of 1". This pipe should be connected to the incoming gas supply for the purpose of delivering gas to the boiler.

30.Line voltage wiring connections (knockouts)

Conduit connection points for the high voltage junction box.

31.Top panel

Removable panel to gain access to the internal components.

32.Power switch

Turns 120 VAC ON/OFF to the boiler.

33.Leveling legs

Used to allow the heat exchanger to be leveled. This is needed for the proper draining of the condensate from the combustion chamber.

34.Air shroud (Model 501 only)

The air shroud controls air and gas flow into the burner.

35.Air pressure switch

The air pressure switch detects blocked flue/inlet conditions. break the control circuit, shutting the boiler down.

36.Pump relay board

The pump relay board is used to connect the boiler, system and DHW pumps.

37.Transformer

The transformer provides 24V power to the integrated control.

16.SMART SYSTEM Control Module

The SMART SYSTEM Control responds to internal and external signals and controls the blower, gas valve, and pumps to meet the heating demand.

17.Manual air vent

Designed to remove trapped air from the heat exchanger coils.

18.Air intake adapter

Allows for the connection of the PVC air intake pipe to the boiler.

38.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.

39.Over-temp switch (located underneath access cover)

Used to detect excessive temperatures on the upper coil of the heat exchanger.

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