Weil McLain Water Heater Parts

Weil-McLain parts are OEM replacement components for Weil-McLain's full range of residential and light commercial hydronic heating boilers, spanning cast-iron boiler series including the CG, CGi, CGA, EG, GV, and Ultra condensing series. Weil-McLain boiler parts on SupplyHouse cover gas valves, ignition components, pilot assemblies, circulator wiring harnesses, sensors, controls, and maintenance kits for supported models. The SupplyHouse Weil-McLain Boiler Parts Finder Tool provides model-number-based parts lookup for all supported Weil-McLain boiler families. Common service parts include gas control valves specific to each boiler series, ignition kits, and pilot assemblies for standing-pilot models. For service technicians, starting with the full model number from the boiler's rating plate is the fastest path to the correct replacement part.

CG, CGi, and CGA Boiler Parts

Weil-McLain CG, CGi, and CGA series boilers are cast-iron gas-fired hydronic boilers with standing pilot or spark ignition configurations. Gas control valves for CG, EG, and CGA boilers (sizes 25-6) use a standing pilot configuration, with part 511-044-360 being a common service part for these series. The CGi series uses spark ignition, with a Pilot Assembly Kit for all sizes (part 510-811-222) and a Circulator Wiring Harness Kit for spark ignition models (part 381-356-528). CG, CGi, and CGA parts must be matched by exact model number due to size-specific heat exchanger and gas control configurations.

GV Boiler Parts

Weil-McLain GV series boilers are gas-fired hot water boilers that use a modulating or combination gas valve configuration. The GV boiler gas valve replacement kit (part 382-200-410) is a common service part that includes the gas valve, left-hand thread adapter, hand valve, mounting bracket, and 12 VDC wiring harness with 24 VAC to 19-21 VDC rectifier. The kit is specified for GV boilers including GV-6 Series 2 applications. Gas valve configuration on GV boilers may use White-Rodgers or Robertshaw components per Weil-McLain parts documentation. All gas valve replacements must be performed by a licensed and qualified technician.

Ultra Condensing Boiler Parts

Weil-McLain Ultra series boilers are condensing gas-fired boilers requiring parts specific to the condensing heat exchanger and sealed combustion design. Ultra boiler parts on SupplyHouse include maintenance kits, cleaning tools, gauge assemblies, and other service items specific to the Ultra series. The condensing design means flue-path components must be rated for acidic condensate contact; standard non-condensing boiler parts are not compatible. Weil-McLain's model-number-based parts lookup is the correct approach for Ultra series parts, as component configurations vary across Ultra boiler sizes.

Combination Gas Control Valves

Weil-McLain combination gas control valves are model-specific replacement parts for gas-fired boiler series requiring a single combination valve body for both safety and modulation functions. The 1/2" x 1/2" combination gas control valve (part 511-044-381) is a common service part for Weil-McLain boilers that use this configuration. Combination gas valves for Weil-McLain boilers have many sub-models; confirming the full part number from the existing valve's label is required before ordering to avoid ordering the wrong sub-model.

How to Choose Weil-McLain Boiler Parts

The boiler model number from the rating plate is the mandatory starting point. Weil-McLain boilers span multiple series and generations, and parts compatibility is model-specific. The SupplyHouse Weil-McLain Boiler Parts Finder Tool accepts the complete model number and returns the compatible parts list, including common service items like igniters, sensors, gaskets, and control components.

For gas control valves, photographing the label on the existing valve before removing it is the most reliable method for identifying the correct replacement. Combination gas valves have many sub-models and the part number on the valve itself is definitive. Cross-referencing that part number with Weil-McLain service documentation before ordering prevents receiving an incompatible valve.

Standing pilot vs. spark ignition is the first configuration split for ignition parts. CG series boilers typically use standing pilot configurations; CGi series uses spark ignition. Parts for the two ignition systems are not interchangeable. The Pilot Assembly Kit (part 510-811-222) is specific to CGi spark ignition configurations.

For anyone asking how to identify which Weil-McLain boiler series they have: the series designation is part of the model number printed on the rating plate, typically on the jacket or combustion chamber. CG, CGi, CGA, EG, GV, Ultra, and WM97+ are distinct series with separate parts catalogs. Confirming the series is required before searching for any replacement component.

FAQs

How do I find the correct Weil-McLain boiler replacement part?
The correct Weil-McLain boiler replacement part is found by entering the full model number from the boiler's rating plate into the SupplyHouse Weil-McLain Boiler Parts Finder Tool. The tool returns the model-specific compatible parts list including gas valves, ignition kits, sensors, controls, and maintenance kits. The model number is located on the boiler's manufacturer nameplate or label, typically on the jacket or combustion chamber.

What does the Weil-McLain GV boiler gas valve replacement kit include?
The Weil-McLain GV boiler gas valve replacement kit (part 382-200-410) includes a negative regulation gas valve, left-hand thread adapter for the outlet, hand valve, mounting bracket, and a 12 VDC wiring harness with a 24 VAC to 19-21 VDC rectifier, per Weil-McLain parts documentation on SupplyHouse. The kit is used with GV boiler models including GV-6 Series 2 and is configured for White-Rodgers or Robertshaw gas valve configurations.

Are Weil-McLain CG and CGi boiler parts interchangeable?
Weil-McLain CG and CGi boiler parts are not fully interchangeable. The CG series typically uses standing pilot ignition, while the CGi series uses spark ignition, creating a split in ignition system parts. Gas valve configurations also differ between series. Parts must be confirmed by the full model number and series designation before ordering.

What is the difference between Weil-McLain parts for condensing and non-condensing boilers?
Weil-McLain Ultra series condensing boiler parts differ from CG, CGi, EG, and GV non-condensing parts in that condensing boiler components must be rated for acidic condensate contact in the flue path and heat exchanger. Non-condensing boiler parts are not compatible with condensing boiler applications due to material and configuration differences. The condensing boiler's sealed combustion design also requires combustion air system components not present in standard atmospheric boilers.

How important is it to use the full part number when ordering Weil-McLain combination gas valves?
Using the full part number is critical when ordering Weil-McLain combination gas valves. Combination gas valves have many sub-models that may share the same general description but differ in valve configuration, inlet/outlet sizing, or control circuit wiring. The full part number is printed on the label on the back of the installed valve and should be photographed before valve removal to ensure the correct replacement is ordered.