Crown Boiler CWI276, CWI172, CWI345, CWI310, CWI103, CWI Series, CWI069, CWI241 XIII Troubleshooting

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XIII Troubleshooting

The following pages contain troubleshooting charts for use in diagnosing control problems. To use these charts, go to the box marked “Start” at the top of the chart on page 37 or 39 and follow the appropriate path though the chart until a box with a list of possible causes is reached. If the problem is known to be within the ignition system, go directly to the appropriate troubleshooting guide for the boiler (standing pilot on page 41 or intermittent ignition on page 42). In using these charts, the following should be kept in mind:

1)These charts are only meant to be used by a professional heating technician as an aid in diagnosing control problems.

2)Where applicable, follow all precautions outlined in the appropriate lighting instructions on pages 29-32.

3)In general, these charts assume that there are no loose or miswired electrical connections. Before using these charts, inspect all electrical connections on the boiler to make sure that they are tight. Also, check the wiring on the boiler against the appropriate wiring diagram in Figures 18 - 21.

4)The possible causes at the end of each branch in these charts are not listed in order of likelihood. All controls on the CWI are tested at least once in the manufacturing process and a defective control or component is generally the least likely cause. Before replacing a component, try to rule out all other possible causes.

5)These troubleshooting charts assume that the vent damper is closed at the beginning of the troubleshooting process. With the 120 volts applied to the boiler and no call for heat, the damper should go to the closed position. If it does not, do the following:

Confirm that 120 volts is applied to the boiler and that there is no call for heat.

Make sure that the switch on the damper is in the “automatic” position.

Unplug the harness from the damper and check for 24 volts across pin #1 (blue) and pin #4 (yellow).

If voltage is present, the damper is defective or there is an obstruction in the path of the damper blade.

If no voltage is present, there is either a loose connection in the damper harness or the limit control (L8148E or L8124E) is defective.

6)If the charts indicate that the L8148E or L8124E is defective, do the following before replacing it:

Check for 24 volts across TV and Z. If no voltage is present, the transformer in the L8148E or L8124E is defective. It is possible that this transformer has been destroyed by a short circuit in the boiler wiring. Before replacing the control, carefully inspect all low voltage wiring on the boiler for places where it is touching the frame of the boiler or wiring on the other side of the transformer.

If 24 volts is present across TV and Z, check for 24 volts between T and W. On L8148Es, if no voltage is present, make sure that the brass jumper is present between W and Z and that the screws holding this jumper in place are both tight. If the boiler is equipped with a L8124E, voltage will only be present across T and W when there is a call for heat AND the boiler water temperature high enough to satisfy the low limit.

If not already done, temporarily replace the thermostat across TV and T with a jumper. If the boiler fires when this is done, there is a problem with the thermostat or zone wiring.

If 24 volts is present across T and W and the relay in the L8148E or L8124E does not pull in, the relay in this control is probably defective. Inspect the coil of this relay for visible heat damage. If such damage is found, there is a good chance that a second transformer is present in the thermostat or zone valve circuit, resulting in the application of 48 volts across the relay coil. In older buildings, this transformer may be hidden in a location far from the boiler. If this second transformer exists, it must be found and removed before the L8148E or L8124E is replaced.

7)When checking voltage across damper harness pins, be careful not to insert the meter probes into the pins. Doing so may damage the pin, resulting in a loose connection when the harness is reconnected.

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Contents CWI Series Gas-Fired Natural Draft Water Boilers INSTALLATION INSTRUCTIONSModels These instructions must be affixed on or adjacent to the boilerI Product Description Table of ContentsFIGURE 1 CWI BOILERS - GENERALCONFIGURATION II SpecificationsTABLE 1 CWI SPECIFICATIONS IV Locating the Boiler III Before InstallingV Air for Combustion and Ventilation ForBuildingsofUnusuallyTightConstruction For Buildings of Other than Unusually Tight ConstructionExample FIGURE 4 ALL AIR FROM OUTDOORS, VENTILATED CRAWL SPACE AND ATTIC FIGURE3BOILERINSTALLEDINCONFINEDSPACE, ALL AIR FROM INSIDEFIGURE 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 FIGURE 9 VENT DAMPER INSTALLATION DETAILS FIGURE8 CWI BOILERTYPICALVENTSYSTEM INSTALLATION AND COMPONENTSVII Gas Piping StandardPiping VIII System PipingDANGER Piping for Special Situations 1413BOILERSIDEPIPING FIGURE 11 STANDARD BOILER PIPING FIGURE 12 INDIRECT WATER HEATERFIGURE13 BOILERBYPASSPIPING FIGURE15 BOILERPIPINGWITHCHILLER FIGURE14 ISOLATIONOFBOILERFROMSYSTEMWITHAHEATEXCHANGERIX TANKLESS HEATER PIPING Feel water before showering or bathing A mixing valve does not eliminate the risk of scaldingFIGURE 17TANKLESSHEATERPIPING SingleZoneWiring IX WiringFIGURE 20 WIRING DIAGRAM, STANDING PILOT WITH TANKLESS HEATER Wiring Variations FACTORY BOILER WIRING NOT SHOWN - SEE FIGURES 18 FIGURE 22 CIRCULATOR ZONEWIRING USING HONEYWELLR845AsFIGURE23ZONEWIRINGUSINGHONEYWELLV8043FZONEVALVES FACTORYWIRING NOT SHOWN - SEE FIGURES 18Sequence of Operation, Standing Pilot, Less Tankless Heater CWI Control System - Sequence of OperationSequence of Operation, Standing Pilot, With Tankless Heater Sequence of Operation, Intermittent Ignition, With Tankless Heater Sequence of Operation, Intermittent Ignition, Less Tankless HeaterSafety Control Operation - Standing Pilot and Intermittent Ignition XI Start-up and CheckoutFIGURE 24 STANDING PILOT BURNER FLAME 2726Page Page LIGHTING INSTRUCTIONS FOR YOUR SAFETY READ BEFORE OPERATINGTO TURN OFF GAS TO APPLIANCE LIGHTING INSTRUCTIONS FOR BOILERS EQUIPPED WITH HONEYWELLLIGHTING INSTRUCTIONS FOR BOILERS EQUIPPED WITH ROBERTSHAW FOR YOUR SAFETY READ BEFORE LIGHTING7000ERHC SERIES GAS VALVES STANDING PILOT OPERATING INSTRUCTIONS FOR YOUR SAFETY READ BEFORE LIGHTINGTO TURN OFF GAS TO APPLIANCE VR8204 AND VR8304 SERIES GAS VALVES INTERMITTENT PILOT7000DERHC SERIES GAS VALVES INTERMITTENT PILOT FIGURE 28b GASVALVEDETAIL-ROBERTSHAW 7000DERHC INTERMITTENT IGNITION FIGURE 27a GASVALVEDETAIL-HONEYWELLVR8200ORVR8300STANDINGPILOTXI Service and Maintenance Heat Exchanger Cleaning Procedure XIII Troubleshooting C1&C2? STARTNational Fuel Gas Code 5&6 onL2 ? STARTT&TV? C1&C2?C2 and Caution Read page 36 before attempting to use this chart Standing Pilot Ignition System Troubleshooting ChartIntermittent Ignition System Troubleshooting Chart XIV PARTS Page 1/4 Pilot Tubing Used with Robertshaw Valves These Valves Piped in Series to Provide Redundent Shut-off40mm BURNERS ONLY Page KEY # Page A. Before Installing Appendix A Knockdown Boiler Assembly InstructionsB. BaseAssembly Preparation C. Heat Exchanger and Flue Collector InstallationFIGUREA1 BASE, HEAT EXCHANGER, FLUE COLLECTORASSEMBLY E. Control and Trim Installation D. Gas Valve InstallationFIGURE A2 JACKET INSTALLATION G. Complete Installation F. Electrical Wiring ConnectionsFIGURE A3 TAPPING LOCATIONS SEE TEXT FOR TAPPING USES 3633 I. Street P.O. BoxPhiladelphia