Crown Boiler 24-05, 24-11, 24-10, 24-08, 24-12, 24-06, 24-09 Maintenance of LOW Water Cutoff Devices

Page 55

b.Using wire or fibre bristle brush clean crown of boiler and inside of water legs.

c.Inspect target wall (903A only) for damage or deterioration. If target wall is damaged, replace.

5.REASSEMBLE BOILER

CAUTION

Do not start the burner unless canopy, smokepipe, burner mounting plate and all flue plates are secured in place.

a.If removed, install the canopy taking care to align the cerafelt strips. If strips are damaged replace as needed.

b.Reinstall burner mounting plate to front section making sure 3/16” diameter rope gasket is in place and forms gas tight seal. If gasket is damaged, replace.

c.Bolt burner to burner mounting plate. Inspect gasket to assure adequate seal. Replace if damaged. Connect oil line(s) and/or gas line(s).

d.Reinstall flue plates making sure gasket on each plate is in place and forms gas tight seal. If damaged, all edges of the cleanout plates should be sealed with Silastic sealant when reinstalled until insulation can be replaced.

e.If removed, reinstall jacket top.

f.Reinstall left side panels.

g.Reinstall smokepipe.

C. MAINTENANCE OF LOW WATER CUTOFF

DEVICES.

NOTICE

Probe and float type low water cutoff devices require annual inspection and maintenance.

1.PROBE TYPE LOW WATER CUTOFF Although these devices are solid state in their operation, the probe is exposed to possible contamination in the boiler water and subject to fouling.

It is important to physically remove the probe from the boiler tapping annually and inspect that probe for accumulation of scale or sediment.

Follow these steps to inspect, clean and/or replace the probe:

a.Turn off electric service to the boiler.

b.Drain boiler water to a level below the tapping for the probe.

c.Disconnect wiring connections between the low water cutoff control and the probe.

d.Dismount the low water cutoff control from the probe.

DANGER

Assure that the boiler is at zero pressure before removing the LWCO probe. Do not rely on the pressure gauge to indicate that the boiler is at zero pressure. Open the safety valve to relieve all internal pressure prior to proceeding. Safety valve discharge piping must be piped such that the potential for burns is eliminated.

e.Unscrew the probe from the boiler tapping.

f.Inspect that portion of the probe that is exposed to the boiler water for a scale or sediment buildup.

g.Light deposits may be removed by wiping the probe with a damp cloth. Wiping the probe with a cloth soaked in vinegar will remove more tenacious lime deposits. The most stubborn deposits may be removed from the probe by using a diluted amount (three 3 parts of water to one (1) part) of phosphoric acid (H2PO4).

WARNING

Exercise caution when handling phosphoric acid and follow the instructions on container label. Always use protective clothing and equipment when working with/near chemicals.

h.Wire brushing of the probe is not recommended as the soft platinum guard ring sandwiched between the ceramic insulators may be damaged. Care must be taken not to damage this ring in any way or the useful life of the probe may be shortened.

i.Clean the pipe threads of the probe to remove old, hardened pipe dope and other foreign matter.

j.Apply a moderate amount of good quality pipe dope to the pipe threads on the probe. Leaving the two end threads bare. Do not use PTFE (Teflon) tape.

k.Screw the probe into the boiler tapping.

l.Mount the low water cutoff control on the probe.

m.Reconnect the control to probe wiring.

n.Fill the boiler to its normal waterline.

o.Add boiler water treatment compound as needed.

p.Restore electric service to the boiler.

q.Fire burner to bring the water in the boiler to a boil to drive off free oxygen.

r.BEFORE RETURNING BOILER TO SERVICE Follow the low water cutoff checkout procedure on Pages 46 and 47.

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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 Locate the Unit Section I General InformationChimney or Vent Boiler FoundationVents Faults & Suggestions Assembly of Sections Manual DRAW- UP Section II Cast Iron Block AssemblyNipple 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 Canopy with Rear Flue Outlet Damper Assembly Section III Installation InstructionsBare Boiler Assembly Avoid Breathing Fiber Particulates and Dust Left Side Canopy Intermediate Bracket Inspect ALL Boiler Seals Mount Rear Observation Port Cover Refer to FigureSeries 24 Jacket Assembly Boiler Models 24-03 thru Mount Burner Adapter Plate to Burner Mounting Plate Burner Mounting Plate Refer to Figures 16Purpose of Tappings Steam Boilers Steam Trim Steam Boilers Install Steam Trim This Is Intentionally Left Blank Purpose of Tappings Water Boilers Water Trim Burner Installation Water Boilers Install Water TrimBoiler 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 CCW Open to System Return Temperature Control and ComponentsWater Boiler Pressure Relief Valve Hook-Up Typical Boiler Wiring with RTC Front Typical Boiler with RTC Return Sensor Rear Fill Heating System with Water Always Inspect Installation BeforeSection IV Operating Instructions Starting BurnerFlame Failure Boil MIN Delay Check Operation of High Limit Control Test ControlsBoiler and System Cleaning Steam Boiler Boiler and System Cleaning Water Boilers Oxygen Corrosion Frequent Water AdditionClean the Boiler Flueways Section V Service InstructionsMaintenance of LOW Water Cutoff Devices Operation General Maintenance ConsiderationsOIL Burners Section VI Burner SpecificationsSection 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 Application Appendix C Valve and Actuator Mounting InstructionsService Record PN 980417 S24 12/05
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