DHW Settings

1 Service

Freeze Protection Burner Differential

Once the burner has started firing due to a low inlet temperature, the inlet temperature must increase by this amount before the burner turns back off. The installer can adjust this differential by accessing the Freeze Protection Burner Differential parameter. The minimum setting is 0°F, and the maximum is 20°F. The default setting is 5°F (2.8°C).

DHW Boiler Set Point

When a DHW call for heat becomes active, the control will use the DHW boiler set point to determine the firing rate of the boiler based on the boiler outlet water temperature, or system temperature when DHW is programmed as a zone.

This parameter can be changed by the installer by accessing the DHW Boiler Set point parameter. The temperature range of this parameter is 68°F (20°C) to 180°F (82°C). The default value is 180°F (82°C).

DHW Tank Set Point

By installing a tank sensor, the SMART SYSTEM control can perform the tank thermostat function. The SMART SYSTEM control automatically detects the presence of this sensor, and generates a DHW call for heat when the tank temperature drops below the tank set point differential (Tank Set point Differential parameter), and finishes the call for heat when the tank temperature reaches tank set point + offset. This parameter can be changed by the installer by accessing the DHW Tank Set point parameter. The temperature range of this parameter tank minimum set point to tank maximum set point. The default value is 125°F (52°C).

Tank Set Point Differential

When a tank sensor is installed, the tank temperature must drop this amount below the tank set point (DHW Tank Set point parameter) before the boiler turns back on. The installer can adjust this setting by accessing the Tank Set point Differential parameter. The minimum setting is 0° (0°C), and the maximum is 40°F (22°C). The default setting is 6°F (3°C).

DHW Boiler Offset

This parameter reflects the degrees above DHW boiler set point the temperature has to go before the boiler will shut off. The range is 0°F (0°C) to 40°F (22°C). The default setting is 10°F (6°C).

DHW Boiler Differential

This parameter reflects the degrees below DHW boiler set point the temperature has to go before the boiler turns back on. The range is 0°F (0°C) to 60°F (33°C). The default setting is 20°F (13°C).

SH/DHW Switching Time

When a boiler has a space heating demand and it receives a DHW demand, it will immediately switch to the DHW demand and start a timer. Once the timer has expired, the boiler will switch back to the space heating demand and start another timer.

Service Manual

Once this timer expires, it will switch back to the DHW demand. The installer can adjust the length of time the boiler will service the space heating demand by accessing SH/DHW Switching Time parameter. The minimum setting is 0 minutes and the maximum setting is 50 minutes. The default time is 30 minutes.

DHW/SH Switching Time

When a boiler has a DHW demand and it receives a space heating demand, the SMART SYSTEM control will start a timer. Once the timer expires, it will stop the DHW demand and service the space heating demand. The installer can adjust the length of time the boiler will service the DHW demand by accessing the DHW/SW Switching Time parameter. The minimum setting is 0 minutes and the maximum setting is 50 minutes. The default setting is 30 minutes.

Tank Minimum Set Point

This setting controls the minimum tank set point for the tank temperature. The installer can adjust this by accessing the Tank Minimum Set point parameter. The minimum setting is 60°F (16°C) and the maximum setting is the maximum tank set point (Tank Maximum Set point parameter). The default value is 60° (16°C).

Tank Maximum Set Point

This setting controls the maximum tank set point for the tank temperature. The installer can adjust this by accessing the Tank Maximum Set point parameter. The minimum setting is the minimum tank set point (Tank Minimum Set point parameter) and the maximum setting is 190°F (88°C). The default value is 140°F (60°C).

DHW Type

This parameter determines whether the Knight XL boiler treats the indirect DHW tank as a separate load, or as a zone on the primary loop. When programmed as a separate load, the boiler will turn on the DHW pump and then turn off the boiler pump when an indirect DHW demand begins. When programmed as a zone, the boiler will turn on the DHW pump, leave the boiler pump on and change the system set point to the DHW boiler set point (DHW Boiler Set point parameter).

This setting may be changed by the installer by accessing the DHW Type parameter. The choices are NORMAL and ZONE. The default setting is NORMAL.

Fan Speed Limiting for Indirect DHW Tank

This parameter determines the maximum fan speed (and therefore the maximum rate) to be used when heating an indirect DHW tank when the DHW Type is set to Normal. This setting may be used when the tank is unable to accept all of the BTU’s available from the boiler. This parameter may be adjusted by the installer by accessing the Fan Speed Limiting for Indirect DHW Tank parameter. The default value is the maximum fan speed for that model.

400-801 specifications

The Lochinvar 400-801 is a high-efficiency commercial boiler that embodies advanced engineering and cutting-edge technology. Designed for a variety of commercial applications, this boiler is known for its reliability, efficiency, and robust performance.

One of the standout features of the Lochinvar 400-801 is its high thermal efficiency, which can reach up to 99%. This efficiency not only reduces fuel consumption but also lowers operating costs, making it an economical choice for businesses seeking to minimize overhead. The boiler employs a stainless steel fire-tube heat exchanger that ensures optimal heat transfer and durability. This construction allows for enhanced resistance to corrosion, thereby extending the boiler's lifespan.

The Lochinvar 400-801 is equipped with advanced control technologies that enhance its performance. With its built-in SMART SYSTEM control, users can easily monitor and manage the boiler’s operations, optimizing performance while ensuring ease of use. This control system features a user-friendly interface that provides real-time data, including temperature settings, pressure readings, and operational status, allowing for quick diagnostics and efficient troubleshooting.

Safety is paramount in the design of the Lochinvar 400-801. The boiler includes a comprehensive safety system that incorporates multiple safety interlocks and a venting system that prevents backflow and ensures safe exhaust. Moreover, the unit is designed to operate with minimal noise, making it suitable for environments where noise reduction is crucial.

Installation and maintenance of the Lochinvar 400-801 are straightforward, thanks to its compact design and multiple venting options. The low-profile construction allows for flexibility in placement, making it an ideal fit for tight spaces. Maintenance tasks are simplified with accessible components, minimizing downtime and ensuring the system operates efficiently over its lifespan.

In conclusion, the Lochinvar 400-801 stands out in the commercial boiler market with its blend of efficiency, reliability, and innovation. With its advanced technologies and features, businesses can achieve significant energy savings while ensuring comfortable and consistent heat for various applications. The Lochinvar 400-801 is an investment in quality and performance, backed by a well-established brand in the heating industry. Whether for a new installation or a replacement, this boiler offers a comprehensive solution for commercial heating needs.

Lochinvar 400-801 service manual DHW Settings

Models: 400-801