Crown Boiler CWI103, CWI172, CWI345, CWI310, CWI276, CWI Series Heat Exchanger Cleaning Procedure

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Heat Exchanger Cleaning Procedure

Heat Exchanger Cleaning Procedure

1)Turn off electrical power and gas supply to the boiler.

2)Disconnect the damper and vent connector from the boiler.

3)Remove the upper front and top jacket panels. If possible, remove the rear and left side jacket panels.

4)Remove the burners.

5)Remove the blocked vent (“spill”) switch.

6)Remove the ¼-20 nuts and washers holding the flue collector onto the heat exchanger.

7)Carefully remove the flue collector gasket strips and set them aside.

8)Remove the flue collector from the heat exchanger.

9)Clean the flue passageways using a stiff bristle brush. Be certain that all foreign material is removed from the gaps between the pins.

10)Clean the bottom surfaces of the heat exchanger.

11)Put a light in the combustion chamber and look through the flue passages from the top to verify that they have been thoroughly cleaned.

12)Replace the flue collector gasket strips. If desired, RTV silicone sealant with a 500F intermittent duty temperature may be substituted for this rope gasket. The flue collector must be thoroughly sealed to the heat exchanger.

13)Replace the ¼-20 nuts and washers that hold down the flue collector.

14)Reattach all the jacket components.

15)Reinstall burners, being careful to put the pilot main burner in its original location.

16)Replace the blocked vent switch.

17)Reconnect the damper and vent system.

WARNING

SOOT DEPOSITS IN THE FLUE PASSAGES ARE A SIGN THAT THE BOILER MAY BE OPERATING AT HIGH CARBON MONOXIDE (CO) LEVELS. AFTER CLEANING THE BOILER OF SOOT DEPOSITS, CHECK THE CO LEVEL IN THE FLUE GAS TO INSURE THAT THE BOILER IS OPERATING PROPERLY.

If it is necessary to check CO, use a combustion analyzer, or other instrument which is designed to measure CO in flue gas. A CO “sniffer” designed for testing CO levels in ambient air cannot be used to check boiler combustion. Take a flue gas sample by inserting a sample probe through the draft diverter opening and into the flue collector so that the sample is taken in the area directly over the heat exchanger. Do not take a sample until the boiler has been firing for at least five minutes.

A normal CO reading for a CWI series boiler is less than 50ppm (0.005%). A reading of more than 100ppm (0.01%) is indicative of a combustion problem.

Some causes of excessive CO include:

Incorrectly sized main burner orifice for the altitude at which boiler is installed

Crooked or out-of-round orifice holes (never attempt to drill orifice for this boiler in the field)

Partially plugged flue passages

Improper manifold pressure

Foreign material in burner venturis or burner ports

Leak in seal between flue collector and heat exchanger

Inadequate supply of combustion air

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Contents Gas-Fired Natural Draft Water Boilers INSTALLATION INSTRUCTIONS CWI SeriesModels These instructions must be affixed on or adjacent to the boilerTable of Contents I Product DescriptionII Specifications FIGURE 1 CWI BOILERS - GENERALCONFIGURATIONTABLE 1 CWI SPECIFICATIONS III Before Installing IV Locating the BoilerV Air for Combustion and Ventilation For Buildings of Other than Unusually Tight Construction ForBuildingsofUnusuallyTightConstructionExample FIGURE3BOILERINSTALLEDINCONFINEDSPACE, ALL AIR FROM INSIDE FIGURE 4 ALL AIR FROM OUTDOORS, VENTILATED CRAWL SPACE AND ATTICFIGURE 5 ALL AIR FROM OUTDOORS VIA VENTILATED ATTIC FIGURE 6 ALL AIR FROM OUTDOORS, USING OPENINGS INTO BOILER ROOM VI Venting Removing an Existing Boiler from a Common Chimney FIGURE8 CWI BOILERTYPICALVENTSYSTEM INSTALLATION AND COMPONENTS FIGURE 9 VENT DAMPER INSTALLATION DETAILSVII Gas Piping VIII System Piping StandardPipingDANGER 1413 Piping for Special SituationsFIGURE 11 STANDARD BOILER PIPING FIGURE 12 INDIRECT WATER HEATER BOILERSIDEPIPINGFIGURE13 BOILERBYPASSPIPING FIGURE14 ISOLATIONOFBOILERFROMSYSTEMWITHAHEATEXCHANGER FIGURE15 BOILERPIPINGWITHCHILLERIX TANKLESS HEATER PIPING A mixing valve does not eliminate the risk of scalding Feel water before showering or bathingFIGURE 17TANKLESSHEATERPIPING IX Wiring SingleZoneWiringFIGURE 20 WIRING DIAGRAM, STANDING PILOT WITH TANKLESS HEATER Wiring Variations FIGURE 22 CIRCULATOR ZONEWIRING USING HONEYWELLR845As FACTORY BOILER WIRING NOT SHOWN - SEE FIGURES 18FIGURE23ZONEWIRINGUSINGHONEYWELLV8043FZONEVALVES FACTORYWIRING NOT SHOWN - SEE FIGURES 18CWI Control System - Sequence of Operation Sequence of Operation, Standing Pilot, Less Tankless HeaterSequence of Operation, Standing Pilot, With Tankless Heater Sequence of Operation, Intermittent Ignition, Less Tankless Heater Sequence of Operation, Intermittent Ignition, With Tankless HeaterXI Start-up and Checkout Safety Control Operation - Standing Pilot and Intermittent Ignition2726 FIGURE 24 STANDING PILOT BURNER FLAMEPage Page FOR YOUR SAFETY READ BEFORE OPERATING LIGHTING INSTRUCTIONSTO TURN OFF GAS TO APPLIANCE LIGHTING INSTRUCTIONS FOR BOILERS EQUIPPED WITH HONEYWELLFOR YOUR SAFETY READ BEFORE LIGHTING LIGHTING INSTRUCTIONS FOR BOILERS EQUIPPED WITH ROBERTSHAW7000ERHC SERIES GAS VALVES STANDING PILOT FOR YOUR SAFETY READ BEFORE LIGHTING OPERATING INSTRUCTIONSTO TURN OFF GAS TO APPLIANCE VR8204 AND VR8304 SERIES GAS VALVES INTERMITTENT PILOT7000DERHC SERIES GAS VALVES INTERMITTENT PILOT FIGURE 27a GASVALVEDETAIL-HONEYWELLVR8200ORVR8300STANDINGPILOT FIGURE 28b GASVALVEDETAIL-ROBERTSHAW 7000DERHC INTERMITTENT IGNITIONXI Service and Maintenance Heat Exchanger Cleaning Procedure XIII Troubleshooting START C1&C2?5&6 on National Fuel Gas CodeSTART L2 ?C1&C2? T&TV?C2 and Standing Pilot Ignition System Troubleshooting Chart Caution Read page 36 before attempting to use this chartIntermittent Ignition System Troubleshooting Chart XIV PARTS Page These Valves Piped in Series to Provide Redundent Shut-off 1/4 Pilot Tubing Used with Robertshaw Valves40mm BURNERS ONLY Page KEY # Page Appendix A Knockdown Boiler Assembly Instructions A. Before InstallingB. BaseAssembly Preparation C. Heat Exchanger and Flue Collector InstallationFIGUREA1 BASE, HEAT EXCHANGER, FLUE COLLECTORASSEMBLY D. Gas Valve Installation E. Control and Trim InstallationFIGURE A2 JACKET INSTALLATION F. Electrical Wiring Connections G. Complete InstallationFIGURE A3 TAPPING LOCATIONS SEE TEXT FOR TAPPING USES P.O. Box 3633 I. StreetPhiladelphia