3 Troubleshooting

WARNING Label all wires prior to disconnection when servicing controls. Wiring errors

can cause improper and dangerous operation. Always disconnect power to the boiler before servicing. Failure to comply could result in severe personal injury, death, or substantial property damage.

WARNING Never jumper (bypass) any device except for momentary testing as

outlined in the Troubleshooting chart. Severe personal injury, death, or substantial property damage can result.

Before troubleshooting:

1.Have the following items:

a.Voltmeter that can check 120 VAC, 24 VAC, and 12 VDC.

b.Continuity checker.

c.Contact thermometer.

2.Check for 120 VAC (minimum 102 VAC to maximum 132 VAC) to boiler.

3.Make sure thermostat is calling for heat and contacts (including appropriate zone controls) are closed. Check for 24 VAC between thermostat wire nuts and ground.

4.Make sure all external limit controls are installed and operating.

Check the following:

1.Wire connectors to control module are securely plugged in at the module and originating control.

2.Gas pressures:

Maximum: 14 inches w.c. (3.5 kPa) (natural and LP) with no flow (lockup) or with boiler on

Minimum: 4 inches w.c. (1.0 kPa) (natural), 8 inches w.c. (2.0 kPa) (LP) with gas flowing (verify during boiler startup)

Service Manual

Check control module fuses

NOTICE

ALWAYS check control module fuses before

replacing control module or any major

 

 

components (blower, etc.). If one of these

 

fuses is blown, it can prevent the control

 

module or other components from operating.

1.Turn OFF the power to the boiler at the external line switch.

2.Remove top access cover.

3.Remove the control module cover.

4.Inspect fuses F1, F2, and F3, see FIG 3-1 below.

Figure 3-1Control Module Fuses

F3 - .80 AMP FUSE

24V DC POWER SUPPLY

F1 - 5 AMP FUSE

PUMPS

F2 - 3.15 AMP FUSE

BLOWER

5.The boiler is shipped with three (3) spare fuses in a plastic bag attached to the control module cover.

6.If necessary, replace open fuse (F3 is .80 amps, F2 is 3.15 amps and F1 is 5 amps).

Note: Fuses F1, F2, and F3 are all slow blow fuses.

WARNING Do not jumper fuse or replace with any fuse except as specified. Failure to comply could

result in severe personal injury, death, or substantial property damage.

7.Install control module cover and top access cover after fuse inspection.

8.Restore power to the boiler at the external line switch and verify boiler operation (Section 10 - Start-up in the Knight XL Installation and Operation Manual) after completing boiler service.

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Lochinvar 400-801 service manual Troubleshooting, Before troubleshooting, Check the following, Check control module fuses

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.