Hydronic Heating Boilers and Domestic Water Heaters

TROUBLESHOOTING GUIDE

399,999 - 750,000 Btu/hr Models

Step 1

Does the power switch

NO

Check the switch for proper

operation. Check the line voltage.

provide power to the unit?

 

 

 

Step 2

YES

 

 

 

 

 

 

Is there 24VAC at B2

NO

Combustion

NO

on the terminal strip?

 

air blower

 

 

 

 

comes on.

 

 

Check the flow switch

 

 

 

 

 

 

Tekmar pins #15 and

 

 

YES

for 24VAC.

 

 

Check all safety limit

 

devices, all connectors

 

behind the control panel

 

and voltage from the

 

transformer to B2.

and

Exchange ignition

#16

module.

Step 3

YES

NO

Check 24VAC at TH (orange wire) on the ignition module.

YES

 

 

Check staging

 

NO

relay (S2). Is

 

 

 

there 120VAC on

Does F2 on ignition module

 

the red wire to the

YES

fan?

 

have 120VAC?

 

 

 

 

 

 

YES

NO

Prepurge light comes on.

NO

Check air pressure

 

Status light does not

switch 24VAC on tan

 

 

 

blink 1 flash continuous.

 

wire (N.O.).

 

 

 

 

 

YES

NO

 

 

 

 

 

 

YES

 

 

 

 

 

 

24VAC at PS (tan wire) at ignition

Check air pressure

 

switch for correct

 

module and/or connector plug for

 

pressures.

 

proving relay secure.

 

Step 4

 

 

 

 

 

 

 

 

Trial for ignition completes

 

 

 

 

Is air switch

 

Check amp draw

YES

bouncing?

and gas valve(s) opens. Does

NO

for 3.1 amps.

 

 

not go into flame failure.

 

 

 

 

 

 

 

 

 

Replace fan.

Replace

 

 

 

 

relay.

 

Replace air pressure

 

YES

switch.

 

NO

Correct air settings.

 

 

 

 

May have to clean

 

 

burners/heat

 

YES

exchanger.

 

NO

Step 5

YES

Replace igniter if less than 2.75 amps.

Unit is running.

NO

Gas valve(s) stays open

YES

Is the flame sense signal to the

and is getting 24VAC.

 

 

 

ignition module 5uA dc or greater?

 

 

 

 

NO

Is 24VAC present at main unit connector (3x3 amp plug) red wire?

NO

Check ignition module pin #05 (replace RLY2402 if no voltage).

NO

YES

Replace gas valve.

 

Check inlet gas pressure both static and dynamic. Check manifold pressure. Check draft. Check air pressure.

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Lochinvar 399, 999 - 750, CF-CH(E)-i&s-08 service manual Troubleshooting Guide
Page 61 Page 63

399, CF-CH(E)-i&s-08, 999 - 750 specifications

Lochinvar 999 - 750, CF-CH(E)-i&s-08,399 is a cutting-edge boiler designed for commercial heating applications. With its robust construction and high efficiency, this model stands out in the crowded market of heating solutions.

One of the main features of the Lochinvar 999 - 750 is its exceptional thermal efficiency rating. The unit incorporates advanced condensing technology that allows it to recover heat from flue gases, which helps in achieving efficiency levels of up to 99%. This efficiency not only reduces energy consumption but also lowers operational costs, making it an excellent investment for businesses looking to minimize their carbon footprint.

The boiler is designed to provide a powerful output of 750 kW, ensuring it meets the heating demands of larger buildings or commercial spaces. Its capacity makes it suitable for a range of applications including schools, hospitals, and industrial facilities. Moreover, the unit features a built-in cascading system that enables multiple boilers to be connected, enhancing system reliability and flexibility.

In terms of technology, the Lochinvar 999 - 750 is equipped with a user-friendly touchscreen interface. This innovative control system allows operators to monitor and adjust settings with ease, providing real-time performance data and alerts for maintenance needs. The intelligent controls optimize operation to match the heating load, further enhancing energy efficiency.

Safety is a top priority with this model. It is built with multiple safety features such as automatic shut-off valves, pressure relief valves, and flame monitoring systems, ensuring safe operation under various conditions. The unit also adheres to stringent industry standards and regulations, making it a reliable choice for commercial applications.

Furthermore, the Lochinvar 999 - 750 is designed with serviceability in mind. Its compact footprint and accessible components simplify maintenance, reducing downtime and associated costs. The unit also supports a variety of fuel sources, including natural gas, propane, and biodiesel, providing flexibility to meet different facility requirements.

In summary, the Lochinvar 999 - 750, CF-CH(E)-i&s-08,399 represents a blend of efficiency, reliability, and safety in commercial heating. Its advanced technologies and thoughtful design make it a powerful solution for various heating needs, making it an ideal choice for businesses aiming for excellence in energy management and operational efficiency.
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