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

Outdoor Knight XL Installation & Operation Manual

The Outdoor 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.

21.Boiler drain port

Location from which the heat exchanger can be drained.

22.Low voltage connection board

The connection board is used to connect external low voltage devices.

23.Low voltage wiring connections (plugs)

Conduit connection points for the low voltage connection board.

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.

6.Flue gas sensor (limit rated - not shown)

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.

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 assembly

Factory-supplied components for complete venting system.

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.

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.

24.Condensate drain connection

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

25.Access cover - front

Provides access to the gas train and the heat exchanger.

26.Ignition electrode

Provides direct spark for igniting the burner.

27.Flame inspection window

The quartz glass window provides a view of the burner surface and flame.

28.Gas shutoff valve

Manual valve used to isolate the gas valve from the gas supply.

29.Relief valve

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

Removable panel to gain access to the internal components.

33.Power switch

Turns 120 VAC ON/OFF to the boiler.

34.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.

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/inlet conditions. break the control circuit, shutting the boiler down.

37.Pump relay board

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

38.Transformer (not shown)

The transformer provides 24V power to the integrated control.

39.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.

40.Over-temp switch (located underneath vent cover - not shown)

An electrical switch designed to shut down boiler operation in the event the outer back of the heat exchanger, directly above the flue connection exceeds 604°F (318°C). This is a one time switch and could warrant a heat exchanger replacement. Check the integrity of the rear refractory at the back of the upper coil if the switch opens.

41.Vent Cover

Covers Over-temp switch and flue collar with flue sensor.

18.Air intake

Provides combustion air to the appliance.

19.Air Intake Cover

Provides protection from outdoor elements.

20.High voltage junction box

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

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42.Flow switch

The flow switch is a safety device that ensures flow through the heat exchanger during operation. This appliance is low mass and should never be operated without flow. The flow switch makes contact when flow is detected and allows the unit to operate. If flow is discontinued during operation for any reason the flow switch will break the control circuit and the unit wll shut down.