Crown Boiler 24-08, 24-11, 24-10, 24-12, 24-06, 24-05, 24-09, 24-03, 24-04 Vents Faults & Suggestions

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If the venting system is designed for positive or forced draft venting, the boiler, vent connector and stack will operate under positive pressure. Gas tight vent systems designed for pressure systems must be used to prevent flue by-product leakage. The vent height is usually limited to prevent negative draft, typically three (3) feet above the roof line (see Figure 3a). The damper shall be adjusted to maintain a positive pressure of 0.1” W.C. in the vent connector box during burner high fire operation (see breeching pressure sensing port in Figure 1).

If the venting system is designed for negative pressure (natural draft), the boiler still operates with positive pressure in the chamber and up to the fixed damper on the flue collar. However, if the venting system is larger than what is required, the stack will provide a surplus draft (or negative pressure) that may require the use of a barometric damper to maintain the positive 0.1” W.C. pressure at the flue outlet. Multiple forced draft boiler stacks should always be designed as negative to ensure the products of combustion do not exit a boiler that is not firing.

WARNING

Venting Instructions are recommendations only. Consult a venting expert on the design of a specific vent system for your application. The ASHRAE Venting Guide and The National Fuel Gas Code, NFPA 54 should be considered in all venting systems.

Conventional vent material may not be suitable for the application. Flue gases can leak carbon monoxide from the joints on these materials and can result in severe personal injury or death.

Installations having long horiz ontal runs or an excessive amount of tees or elbows will restrict the flow of combustion gases and can result in condensation, flue gas leakage of carbon monoxide, resulting in severe personal injury or death.

FIGURE 3b: VENTS — FAULTS & SUGGESTIONS

TYPICAL VENTS THAT ARE USED ON FORCED DRAFT BOILERS, ON LOW SILHOUETTE BUILDINGS

A

B

C

RAIN CAP

“A” CAP

 

TEE TYPE

RIGHT

RIGHT

 

RIGHT

 

 

 

 

D

 

E

90°

 

 

 

ELBOW

 

 

 

UP or DOWN

WRONG

 

WRONG

 

VENT SIZING - Area must be the same as or greater than the boiler breeching (Smoke Outlet). A barometric damper may be required on installations with a high draft condition.

FAULTY BOILER BURNER OPERATION

1.If improper vent is suspected, remove pipe at breeching and operate boiler. This will determine if excessive down draft, blocked or restricted flue, etc. is causing the problem.

2.If using type shown in A above, be sure cap is raised sufficiently above main pipe to allow flue gases to vent unimpeded.

3.A popular type cap is shown in B.

4.The tee is frequently used as shown in C.

5.D and E should not be used due to possible fluctuations in back pressure.

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Contents Series Page Important Information Read Carefully Page Page Table of Contents Table of Contents Section I General Information Boiler RATINGS/DATA Section I General Information Locate the UnitBoiler Foundation Chimney or VentVents Faults & Suggestions Section II Cast Iron Block Assembly Assembly of Sections Manual DRAW- UPNipple Gauge Series 24 Section Arrangement Draw-Up Rods Alternating Pattern Manual Draw-up Center Section Channel Block Position Partial Block Draw-Up Hydraulic Draw-Up of Sections Section III Installation Instructions Canopy with Rear Flue Outlet Damper AssemblyBare Boiler Assembly Avoid Breathing Fiber Particulates and Dust Left Side Canopy Intermediate Bracket Mount Rear Observation Port Cover Refer to Figure Inspect ALL Boiler SealsSeries 24 Jacket Assembly Boiler Models 24-03 thru Burner Mounting Plate Refer to Figures 16 Mount Burner Adapter Plate to Burner Mounting PlatePurpose of Tappings Steam Boilers Steam Trim Steam Boilers Install Steam Trim This Is Intentionally Left Blank Purpose of Tappings Water Boilers Water Trim Water Boilers Install Water Trim Burner InstallationBoiler Piping Heating Applications Page Parallel Piping Conversion Recommendation 1 Use when Recommendation 2 Use when Recommendation 3 Use when Page Page Page BMounting Elevations M&M 150, 64 Float Low Water Cut-offs Schematic Tankless Heater Piping 24-08 24-09 Return Temperature Control and Components CCW Open to SystemWater Boiler Pressure Relief Valve Hook-Up Typical Boiler Wiring with RTC Front Typical Boiler with RTC Return Sensor Rear Always Inspect Installation Before Section IV Operating InstructionsStarting Burner Fill Heating System with WaterFlame Failure Boil MIN Delay Test Controls Check Operation of High Limit ControlBoiler and System Cleaning Steam Boiler Boiler and System Cleaning Water Boilers Frequent Water Addition Oxygen CorrosionSection V Service Instructions Clean the Boiler FluewaysMaintenance of LOW Water Cutoff Devices General Maintenance Considerations OperationSection VI Burner Specifications OIL BurnersSection VII Repair Parts & Carton Contents Series 24 Master Parts List Section VII Repair Parts Jacket Carton Bare Boiler Assembly Section Joiner Carton Assy Rear Target Wall Carton Standard Steam Trim Carton Assy RTC Carton with Outdoor Reset Tankless Coil Components Boiler Water Section Viii Appendix Page Mechanical Page Mechanical Electrical Page Page Page Page Page Page Page Page Series 24 Boiler Circulator Selection Taco 20F Differential Boiler Recirculation Grundfos Circulating Pump Way Boiler Recirculation Bell and Gossett Circulating Pump Way Boiler Recirculation Armstrong Circulating Pump Way Appendix C Valve and Actuator Mounting Instructions ApplicationService Record PN 980417 S24 12/05
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