Service Manual

3Troubleshooting

￿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.

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.

￿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)

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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 F2, F3, F4, and F5, see FIG 3-1 below.

Figure 3-1Control Module Fuses

F3 - 1.25 AMP FUSE

MAIN BOARD

F4 - 3.15 AMP FUSE

GAS VALVE

F5 - 5 AMP FUSE

PUMPS

F2 - 3.15 AMP FUSE

24V SUPPLY

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 1.25 amps, F2 and F4 are 3.15 amps, and F5 is 5 amps).

Note: Fuses F2 - F5 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 Boiler Installation and Operation Manual) after completing boiler service.

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Lochinvar 399 - 800 service manual Troubleshooting, Check control module fuses, Before troubleshooting, Check the following

399 - 800 specifications

Lochinvar is known for its cutting-edge water heating and boiler systems, and the Lochinvar 399 - 800 series is no exception. Specifically designed for commercial applications, this series brings advanced technology and engineering to the forefront of hydronic heating solutions.

One of the standout features of the Lochinvar 399 - 800 series is its impressive efficiency. Equipped with a condensing design, these boilers utilize high-efficiency stainless steel heat exchangers that allow for maximum heat transfer while minimizing energy consumption. With an impressive thermal efficiency of up to 96%, the Lochinvar 399 - 800 series stands out in its class, offering significant energy savings and reduced operational costs over time.

Another key characteristic of this series is its robust construction. Designed with longevity in mind, the boilers are built using high-quality materials that withstand extreme temperatures and pressures. The stainless steel design not only enhances durability but also combats corrosion, ensuring a long service life and reduced maintenance costs for users.

The Lochinvar 399 - 800 series also incorporates advanced control technologies. With its intuitive control system, users can easily adjust and monitor heating parameters, ensuring optimal performance and comfort. The integrated Control Wizard feature simplifies the setup process, allowing for quick commissioning and troubleshooting. Additionally, the optional Lochinvar SMART CONTROL technology provides remote monitoring capabilities, allowing operators to keep track of system performance from anywhere.

Versatility is another hallmark of the Lochinvar 399 - 800 series. These boilers come in a range of sizes, with the ability to modulate output based on real-time heating demands. This flexibility ensures that systems can operate efficiently under varying load conditions, making them ideal for schools, hospitals, and commercial buildings requiring consistent hot water availability.

In summary, the Lochinvar 399 - 800 series exemplifies modern boiler technology, combining energy efficiency, durability, advanced controls, and versatility. As businesses and facilities seek to enhance their heating systems, the Lochinvar 399 - 800 offers a reliable and forward-thinking solution for today's energy-conscious environment. Investing in this state-of-the-art boiler system not only improves comfort but also fosters sustainability and cost-effectiveness in commercial heating applications.