When your boiler fails to produce heat, cycles loudly, or shows a leak, the first impulse is to search “Weil-McLain boiler parts near me.” That’s usually because the problem points to a replaceable component (a failed pump, sensor, or control board) rather than the whole boiler. Common search triggers include: “no heat”, repeated ignition attempts, pressure that jumps, or a circulator that hums but won’t move water.
This article helps U.S. homeowners and property managers:
- Identify the Weil-McLain parts most likely to fail.
- Find local and online sources that stock genuine Weil-McLain parts.
- Estimate what replacement parts typically cost (price checks noted).
- Decide when a DIY swap is reasonable — and when to call a licensed pro.
Quick takeaway: if the issue involves gas flow, combustion, wiring, or pressure safety devices, stop and call a licensed technician. Don’t attempt gas or electrical repairs yourself.
Quick safety note & when to call a pro
Safety first: Boilers are gas, high-temperature water, and electrical systems all at once. Do not perform gas valve replacements, burner work, high-voltage wiring, or any actions that void combustion safety. Follow manufacturer warnings in your Weil-McLain manual and on the boiler data plate. Manuals instruct keeping model and CP numbers handy when ordering parts.
When to call a licensed HVAC tech:
- Flame failure, gas smell, or frequent lockouts.
- Visible leaks at the heat exchanger or pressure relief valve.
- Noisy circulator bearings, suspected heat-exchanger cracks, or repeated short-cycling.
- Any job that requires isolating gas, removing burners, or opening pressurized boiler piping.
Bold safety callout: If you smell gas — evacuate, call your gas company, and call a pro.
READ MORE: Weil‑McLain Boiler Reviews (2026)
How Weil-McLain model numbers and part numbering work
Every Weil-McLain boiler has a data plate (rating label) on the boiler jacket or control box. That label contains the model number, serial number, and often a CP or production code. When dealers or the manufacturer ask for help, they’ll request the boiler model and CP numbers — these tell them exactly which parts fit your unit. The Weil-McLain manuals emphasize recording those numbers before ordering parts or starting service.
How part numbers are structured:
- Weil-McLain OEM parts usually have numeric or alphanumeric part SKUs (for example, ignition module part numbers like 511-330-099).
- Some parts are model-family specific (CGi, Ultra, WM97), while others (thermostats, general gaskets) are shared across families.
- Retailers list compatibility notes — always confirm the part SKU against your boiler model.
Practical steps (no repair instructions):
- Photograph the data plate and the suspect part (clear close-ups).
- Note the boiler family (e.g., CGi, Ultra, WM97), the model #, and CP code.
- If you call a local parts counter, give them the part SKU or show the photo it speeds up matching.
Compatibility tip: Some electronic modules look similar but have different firmware or connectors. When in doubt, request OEM Weil-McLain parts by number rather than buying a visually similar aftermarket replacement.
READ MORE: Plate Heat Exchanger Spare Parts: The U.S. Homeowner’s Guide
The Core 15: Essential Weil-McLain Parts and Their Failure Symptoms
Understanding the function of your boiler’s internal organs allows you to better communicate with a technician and verify that you are purchasing the correct components.
1. Ignition Control Module
The ignition control module is the “brain” of the boiler. It coordinates the safety checks, starts the spark or hot-surface igniter, and monitors the flame.
- Symptoms of Failure: The boiler “clicks” but never fires; the unit goes into “lockout” mode; the “Flame” or “Ignition” light flashes on the display.
- Compatibility tip: Modules are model-specific (CGi, EVG, EGH series). Expect OEM part SKUs like 511-330-099 on CGi units.
2. Flame Sensor / Flame Rod
This small metal rod sits in the path of the burner flame. It uses a process called flame rectification to tell the control module that it is safe to keep the gas valve open.
- Symptoms of Failure: The boiler lights for 2-5 seconds and then immediately shuts off.
- Compatibility tip: Small and inexpensive — confirm length and connector style.
- Compatible with the following models: 511330148, 511-330-148, W511330148, IG0148, with strong replacement adaptability f…
- Included Accessories: Comes with a dedicated mounting bracket, ready for installation right out of the box, saving the s…
- with precise interface matching and no modification required
3. Pressure Relief Valve (PRV)
A critical safety device designed to open and discharge water if the system pressure exceeds 30 PSI (for most residential water boilers).
- Symptoms: Dripping or continuous leakage from the relief port.
- Compatibility tip: Must match boiler pressure rating (e.g., 30 psi or specific ASME spec). OEM PRVs are stocked by supply houses.
4. Circulator Pump (Boiler Pump)
What it does: Circulates hot water through radiators/baseboards.
- Symptoms: No heat in radiators despite hot boiler; pump hums or leaks.
- Compatibility tip: Sold as cartridge or full-unit assemblies. Prices range wide depending on horsepower and materials; many Weil-McLain pumps are available through HVAC suppliers.
- “Direct Fit Replacement – Engineered as an upgraded replacement component providing complete compatibility for quick, ac…
- “Durable Construction – Manufactured with premium-grade materials to ensure extended service life, improved reliability,…
- “Reliable Performance – Designed to meet industry engineering specifications ensuring consistent operation across reside…
5. Gas Valve (Control Valve/Combo Valve)
- What it does: Regulates gas flow to the burner.
- Symptoms: No gas to burner, unsafe flow, or failure to shut off
- Compatibility tip: OEM gas valves must be matched exactly — gas valve replacement should be performed by a licensed technician.
6. Draft Inducer / Fan Motor
- What it does: Ensures proper combustion airflow
- Symptoms: Lockouts, noisy fan, or failure to start.
- Compatibility tip: Verify mounting style and electrical connections.
- ▶ This is a Brand New ClimaTek Furnace Draft Inducer Exhaust Motor
- ▶ Top Quality ClimaTek Replacement Part, Built to Last!
- ▶ This ClimaTek Part Directly Replaces Part #s JE1D014N
7. Expansion Tank (Diaphragm Tank)
- What it does: Absorbs thermal expansion in closed-loop systems.
- Symptoms: Pressure swings, waterlogging, or brief water discharge from PRV.
- Compatibility tip: OEM Fill-Trol tanks and model-specific tanks are available from major dealers.
8. Heat Exchanger Gasket / Burner Door Gasket
- What it does: Seals combustion chamber access panels.
- Symptoms: Soot, unusual combustion odors, or airflow leaks.
- Compatibility tip: Often sold in gasket kits by model family.
- Weil Mclain 383-500-620 Maintenance Kit for Ultra Gas Boilers Sizes 155, 230, 299, and 399
- This Kit Includes: Igniter Igniter gasket Cover plate gasket Cover plate insulation Burner gasket Venturi gasket
9. Aquastat / Temperature Limit Control
- What it does: Controls boiler operating temperature and safety cutoffs.
- Symptoms: Short-cycling, incorrect temperature, or no call for heat.
- Compatibility tip: Note whether it’s an OEM electronic aquastat or older mechanical type.
- Weil Mclain 633-900-130 Thermostat (Aquastat) Kit For Residential Indirect Water Heaters
- For Use With GOLD / Ultra Plus 30/40/60/80
- Includes Knob And Instructions 90°F-160°F Adjustable Range Does NOT Include Cover Plate
10 Low-Water Cutoff (LWCO)
- What it does: Prevents operation when water is low (steam boilers).
- Symptoms: Safety lockouts or unexpected shutoffs.
- Compatibility tip: Critical safety device — replacement should meet OEM spec.
- LOW WATER CUT-OFF; ULTRA, SLIMFIT, WM97+, WM97+ CT USED ON MODEL/BRAND; GAS BOILER USED ON ITEM; WM97+70/110, CT 70/110 …
11. Burner Orifice / Injector
- What it does: Meters gas into the burner for proper combustion.
- Symptoms: Poor flame shape, sooting, or efficiency loss.
- Compatibility tip: Orifice size is gas-type and model dependent; techs carry sets.
12. Control Relay Board / Transformer
- What it does: Powers low-voltage controls and switching.
- Symptoms: Multiple control failures, dead thermostats, or no 24V power.
- Compatibility tip: Match board part numbers; some boards are common across sizes.
- Fits many Weil Mclain Draft induced Gas Boilers
13. Gasket Kit / Burner Door Seals
- A collection of seals required for annual maintenance.
- Pro Tip: Buying the kit is usually 30% cheaper than buying individual seals.
14. Thermostat (2-wire/3-wire)
- The user interface that tells the boiler when to start.
- Symptoms of Failure: Blank screen; clicking noise at the thermostat but no action at the boiler; temperature readings that are wildly inaccurate.
15. Fan or Draft Inducer Motor
- Found in power-vented (CGi) or condensing (Ultra/Evergreen) models, this fan ensures that exhaust gases are pushed out of the vent and that fresh air is pulled in for combustion.
- Symptoms of Failure: High-pitched squealing; the boiler won’t start because the pressure switch doesn’t detect airflow; the fan is visible but not spinning.
Where to buy Weil-McLain parts near you
Local options:
- Authorized Weil-McLain dealers and wholesalers — your best bet for OEM parts and warranty coverage. Many carry common parts for same-day pickup. Ask for the parts department and give them your boiler model & CP number.
- Plumbing & HVAC supply houses (Ferguson, Liberty Supply, SupplyHouse, AF Supply) — national suppliers with in-store pickup and fast shipping. These stores list OEM part numbers and compatibility.
Online marketplaces & retailers:
- Manufacturer OEM channels — Weil-McLain sometimes lists parts or directs you to authorized dealers.
- Major online retailers (Amazon) — good for small items like flame sensors or gaskets; watch for seller authenticity.
- Specialty HVAC online suppliers — often have the best stock of model-specific modules, gas valves, and pumps.
How to verify OEM vs aftermarket:
- Ask for the Weil-McLain part number and packaging photos. OEM parts come in factory packaging and are listed with SKU numbers. Reputable suppliers will state “Weil-McLain OEM” or show the manufacturer part number. For safety-critical parts (gas valve, LWCO, PRV), prefer OEM.
READ MORE: Heat Exchangers Explained | Types, Uses, Efficiency & Benefits
How to Check Price of Weil-McLain Boiler Parts
Record exact part info first: Photograph the part, note the model and CP numbers, and write down the part SKU printed on the part (if present). Having this information before you call saves time and reduces returns.
Steps to check availability:
- Search supplier SKU — use SupplyHouse, AF Supply, Ferguson, and authoritatively-named Weil-McLain dealers for real-time stock.
- Call the local supply house parts counter — asking for the SKU yields immediate availability and pickup windows.
- Compare shipping times — some OEM parts ship from regional warehouses (1–7 business days). If you need same-day, ask local wholesalers.
Note: Electronic modules and larger items (pumps, heat exchangers) can be pricier to ship; check return policies before ordering.
Professional Maintenance: The Best Way to Avoid Needing Parts
A quote from the hydronic archives: “A boiler is a water-based machine. If you ignore the water chemistry, the machine will ignore your request for heat.” This highlights that most part failures are secondary to poor maintenance.
The Annual Checkup
A qualified technician will perform several tasks that prevent the 15 parts listed above from failing:
- Combustion Analysis: Ensures the burner is not “over-firing,” which melts sensors and warps heat exchangers.
- System Flushing: Removing sludge protects the circulator pump from seizing.
- Pressure Testing: Verifying the expansion tank’s air charge prevents the PRV from leaking.
FAQ
Where can I buy Weil-McLain boiler parts near me?
Local Weil-McLain dealers, HVAC supply houses (Ferguson, SupplyHouse, AF Supply), and major online marketplaces stock parts. Always have your boiler model and CP number ready when you call.
How do I find the Weil-McLain part number on my boiler?
Check the data plate (rating label) on the boiler jacket or control box for model and serial/CP numbers, then photograph the faulty part and any printed SKU. Manuals advise giving those numbers when ordering parts.
Are Weil-McLain parts interchangeable between models?
Sometimes. Some parts (gaskets, certain controls) are shared across model families; many electronic modules and valves are model-specific. Confirm by part SKU and boiler model before ordering.
Can I install Weil-McLain parts myself?
Minor parts like thermostats or filters may be DIY-friendly. Do not attempt gas valve, burner, or heat exchanger work these require a licensed technician for safety and code compliance.
How much do common Weil-McLain replacement parts cost?
Costs vary widely. As of Feb 25, 2026, ignition modules often retail $150–$350, circulator pumps $150–$400+, PRVs $40–$150, and gas valves $200–$700. Always check current local pricing and note the date of your price check.
Closing — call to action
If you’re searching “Weil-McLain boiler parts near me,” start by photographing the data plate and the failed part, then call your local Weil-McLain dealer or supply house with those details. For safety-critical failures (gas valves, combustion issues, heat exchanger concerns), call a licensed HVAC technician and share the part SKU — it speeds diagnosis and repair.
