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Weil McLain Boiler Parts

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Product Image of Indicating Lamp Bulb, 24v, Incandescent (120MB), 591-850-370
$12.90 each
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Product Image of WELL LMT 1/2" Honeywell 123869A, 592-300-017
$32.44 each
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Product Image of 3/8" Sealing Rope (1 ft. Length), 590-735-150
$9.07 each
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Product Image of Manifold C for LGB Boilers, 591-125-912
Manifold C for LGB Boilers, 591-125-912
SKU: 591-125-912
Weil-McLain
SKU: 591-125-912
Brand: Weil-McLain
$347.23 each
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Product Image of 3/4" NPT Manifold Assembly for CGI Boilers, 591-126-740
$163.26 each
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Product Image of Insulation End Panels LGB, 591-221-126
Insulation End Panels LGB, 591-221-126
SKU: 591-221-126
Weil-McLain
SKU: 591-221-126
Brand: Weil-McLain
$70.60 each
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Product Image of Insulation Blanket (.50 x 1.88 x 10.50), 591-221-270
$8.51 each
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Product Image of Front Base Insulation (7.69 x 25.00 x 1.00), 591-221-340
$75.18 each
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Product Image of Back Base Insulation EG-6, 591-222-061
Back Base Insulation EG-6, 591-222-061
SKU: 591-222-061
Weil-McLain
SKU: 591-222-061
Brand: Weil-McLain
$23.22 each
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Product Image of Wiring Harness, 591-319-795
Wiring Harness, 591-319-795
SKU: 591-319-795
Weil-McLain
SKU: 591-319-795
Brand: Weil-McLain
$78.69 each
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Product Image of Jacket Hardware Kit, 569-928-025
Jacket Hardware Kit, 569-928-025
SKU: 569-928-025
Weil-McLain
SKU: 569-928-025
Brand: Weil-McLain
$43.20 each
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Product Image of Wiring Harness, Control Module to: Thermostat, Block Switch, Limit, Pressure Switch, Gas Valve - for GV Boilers, 591-391-820
$79.52 each
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Product Image of Junction Box - Wiring Harness Assembly Series 2 and 3 WTGO-3L
$45.19 each
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Product Image of Harness-Wiring 0-10V, 591-392-010
Harness-Wiring 0-10V, 591-392-010
SKU: 591-392-010
Weil-McLain
SKU: 591-392-010
Brand: Weil-McLain
$42.34 each
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Product Image of Blue Indicating Lamp Lens, 591-850-201
Blue Indicating Lamp Lens, 591-850-201
SKU: 591-850-201
Weil-McLain
SKU: 591-850-201
Brand: Weil-McLain
$21.19 each
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Product Image of Heater Cover Plate w/ 1-1/2" Hole, 592-243-216
$86.04 each
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Product Image of Cover Eco 5-6, 593-000-003
Cover Eco 5-6, 593-000-003
SKU: 593-000-003
Weil-McLain
SKU: 593-000-003
Brand: Weil-McLain
$50.68 each
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Product Image of Gasket for Supply Outlet, 590-317-546
Gasket for Supply Outlet, 590-317-546
SKU: 590-317-546
Weil-McLain
SKU: 590-317-546
Brand: Weil-McLain
$50.66 each
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Product Image of 5/8" Silicone Coating Sealing Rope, 590-735-154
$218.85 each
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Product Image of 1.55mm Main Burner Orifice (Propane Gas), 591-125-533
$118.08 each
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Product Image of Burner Manifold EGH-8, 591-125-548
Burner Manifold EGH-8, 591-125-548
SKU: 591-125-548
Weil-McLain
SKU: 591-125-548
Brand: Weil-McLain
$97.46 each
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Product Image of Manifold A for LGB Boilers, 591-125-910
Manifold A for LGB Boilers, 591-125-910
SKU: 591-125-910
Weil-McLain
SKU: 591-125-910
Brand: Weil-McLain
$282.98 each
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Product Image of Front Base Insulation (7.69 x 31.12 x 1.00), 591-221-336
$79.52 each
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Product Image of Boiler Insulation UO-3, 591-222-178
Boiler Insulation UO-3, 591-222-178
SKU: 591-222-178
Weil-McLain
SKU: 591-222-178
Brand: Weil-McLain
$151.36 each
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Product Image of Jacket Rear Panel Insulation, 591-222-181
Jacket Rear Panel Insulation, 591-222-181
SKU: 591-222-181
Weil-McLain
SKU: 591-222-181
Brand: Weil-McLain
$18.29 each
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Product Image of Wiring Harness for PFG 6-8, 591-391-880
Wiring Harness for PFG 6-8, 591-391-880
SKU: 591-391-880
Weil-McLain
SKU: 591-391-880
Brand: Weil-McLain
$131.74 each
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Product Image of Wiring Harness - Control Module to Junction Box, 591-391-891
$37.35 each
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Product Image of Harness-Wiring Ctl to Mod-C CGi S3, 591-391-978
$28.28 each
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Product Image of Wire Harness for ECO 70 (Low Voltage), 591-392-000
$149.52 each
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Product Image of Observation Glass 92 & 94, 591-419-198
Observation Glass 92 & 94, 591-419-198
SKU: 591-419-198
Weil-McLain
SKU: 591-419-198
Brand: Weil-McLain
$68.18 each
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Product Image of Plastic Jacket Cover (Top/Front), 595-000-001
$37.47 each
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Product Image of Universal Sensor for Ultra Oil Boilers, 650-000-095
$52.34 each
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Product Image of Automatic Air Vent, 510-148-563
Automatic Air Vent, 510-148-563
SKU: 510-148-563
Weil-McLain
SKU: 510-148-563
Brand: Weil-McLain
$71.89 each
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Product Image of Inducer Assembly, 510-312-301
Inducer Assembly, 510-312-301
SKU: 510-312-301
Weil-McLain
SKU: 510-312-301
Brand: Weil-McLain
$326.56 each
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Product Image of Balanced Draft Damper, 510-512-267
Balanced Draft Damper, 510-512-267
SKU: 510-512-267
Weil-McLain
SKU: 510-512-267
Brand: Weil-McLain
$69.30 each
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Product Image of Fill-Trol Diaphragm Expansion Tank, 510-632-088
$273.63 each
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Product Image of Conversion Kit for EGH Boilers, 510-811-457
$844.00 each
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Product Image of Natural Gas to Propane Gas Conversion Kit for GV Boilers (GV-5), 510-811-610
Natural Gas to Propane Gas Conversion Kit for GV Boilers (GV-5), 510-811-610
SKU: 510-811-610
Weil-McLain
SKU: 510-811-610
Brand: Weil-McLain
$90.35 each
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Product Image of High Limit Temperature Control for HE, HE II, VHE Boilers, 510-312-015
$394.06 each
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Product Image of Natural to LP Gas Conversion Kit for Series 3, CA 25-7 Boilers, 510-811-980
$391.67 each
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Product Image of Regulator 2", 510-933-203
Regulator 2", 510-933-203
SKU: 510-933-203
Weil-McLain
SKU: 510-933-203
Brand: Weil-McLain
$1,466.10 each
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Product Image of Purge Timer Kit, 510-350-430
Purge Timer Kit, 510-350-430
SKU: 510-350-430
Weil-McLain
SKU: 510-350-430
Brand: Weil-McLain
$425.58 each
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Product Image of NG to LP Conversion Kit for CGs-3, CGs4, CGs-5 & CGs-6 Boilers, 510-811-096
$414.75 each
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Product Image of 3/4" NPT Solenoid Vent Valve, 511-046-340
3/4" NPT Solenoid Vent Valve, 511-046-340
SKU: 511-046-340
Weil-McLain
SKU: 511-046-340
Brand: Weil-McLain
$753.21 each
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Product Image of Kit-S LWCO-P Stm Foam Hyd, 511-100-008
Kit-S LWCO-P Stm Foam Hyd, 511-100-008
SKU: 511-100-008
Weil-McLain
SKU: 511-100-008
Brand: Weil-McLain
$322.70 each
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Product Image of Pilot Burner with Propane Orifice, 511-330-196
$251.46 each
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Product Image of Circulator Cartridge with Gaskets and Hardware, 511-405-006
$250.99 each
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Product Image of Limit Control Sensor, 511-724-291
Limit Control Sensor, 511-724-291
SKU: 511-724-291
Weil-McLain
SKU: 511-724-291
Brand: Weil-McLain
$90.35 each
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Articles
More About Weil McLain Boiler Parts

Weil-McLain Boiler Parts cover the components that keep Weil-McLain's cast iron and stainless steel boilers running across the company's residential and commercial product lines. Weil-McLain, headquartered in Burr Ridge, Illinois, describes itself as a leading North American manufacturer of hydronic heating systems, with a lineup spanning residential gas boilers like the CGa and CGi series and Ultra models to commercial units including the SVF stainless vertical firetube line.

Replacement parts for these boilers range from ignition components and control boards to heat exchanger sections and circulator parts, since a cast iron boiler built to last decades often needs individual components replaced well before the boiler itself reaches the end of its service life. Technicians servicing a mixed fleet of Weil-McLain equipment typically stock parts across several model generations, since older cast iron boilers remain in service alongside newer high efficiency models.

Subcategories

  • Ignition and Control Components: Ignition and control components include igniters, flame sensors, and control boards that manage the boiler's start sequence and safety shutoffs. A boiler that fails to light or locks out repeatedly often traces back to one of these parts rather than a larger mechanical failure.
  • Heat Exchanger Parts: Heat exchanger parts cover the sections, gaskets, and seals specific to a cast iron sectional boiler or the tubes and headers used in stainless models like the SVF series. Replacing a cracked section or a failing gasket restores efficient heat transfer without requiring a full boiler replacement.
  • Circulator and Pump Parts: Circulator and pump parts keep hot water moving between the boiler and the building's heating zones, and they see more wear than most other boiler components due to constant operation through the heating season. Technicians commonly stock cartridges, flanges, and seals for the circulator models paired most often with Weil-McLain boilers.
  • Venting and Flue Parts: Venting and flue parts route combustion byproducts safely outside the building, and the specific components depend on whether the boiler uses atmospheric, power vented, or direct vent design. Corroded or damaged venting on an older cast iron boiler needs prompt replacement to keep combustion venting safely.

Buying Guide

Identifying the correct part starts with the boiler's model and series information, typically found on a nameplate attached to the jacket or control panel. Weil-McLain has produced multiple boiler generations over the years, from older cast iron sectional units still running in many buildings to newer high efficiency models like the Evergreen Pro and ECO Tec, and parts are rarely interchangeable across generations.

Cast iron boilers often stay in service for decades, so a technician working on an older unit needs to confirm whether a specific section, gasket, or control component is still produced for that model before promising a repair timeline. Newer boiler generations typically carry a broader current parts inventory, since they remain in active production.

Weil-McLain Boiler Parts split broadly between components shared across a product family, like circulator cartridges and certain control boards, and components specific to a single model, like cast iron sections sized to one boiler's output rating. Confirming which category a needed part falls into before ordering avoids delays from a part that will not fit the installed unit.

Commercial boilers, including the SVF stainless vertical firetube line, generally use different parts than residential cast iron models due to their different construction and larger output range. Technicians who service both residential and commercial Weil-McLain equipment typically maintain separate parts references for each product family to avoid confusion between similar sounding components.

Frequently Asked Questions

How can a technician identify the correct part for an older Weil-McLain boiler?

The model and series information on the boiler's nameplate identifies which parts fit, and checking that information against current parts availability confirms whether an older model's components are still produced. Cast iron boilers especially can span several design generations that are not interchangeable.

Are parts interchangeable between residential and commercial Weil-McLain boilers?

Residential cast iron models and commercial units like the SVF stainless vertical firetube series generally use different parts due to their different construction and output ranges. Checking parts documentation specific to the boiler's product family avoids ordering a component built for the wrong line.

What commonly fails first on an aging cast iron boiler?

Ignition components, control boards, and circulator parts tend to wear out well before the cast iron sections themselves, since those parts see more electrical and mechanical cycling through each heating season. A boiler that locks out repeatedly or loses circulation often points to one of these components rather than the boiler body.

Does Weil-McLain still produce parts for older discontinued boiler models?

Parts availability for discontinued models varies by how long ago a boiler generation was phased out of production, with newer generations generally carrying broader current stock. Confirming availability for a specific older model before committing to a repair timeline helps set accurate expectations.

What venting components need checking during a boiler service call?

Venting and flue components need inspection for corrosion or damage, since the specific parts depend on whether the boiler uses atmospheric, power vented, or direct vent design. A corroded flue on an older cast iron boiler needs prompt replacement to keep combustion venting safely outside the building.