Why Weil-McLain Boilers Are Worth It
You’ve probably heard the name Weil-McLain before—and for good reason. These guys have been building dependable boilers for over a century, and they don’t mess around when it comes to performance. In all my years crawling through basements and boiler rooms, Weil-McLain has earned my respect. Their units are rugged, serviceable, and built to heat consistently through the worst winters.
From cast iron gas boilers to high-efficiency condensing models, they’ve got a full lineup that works for everything from two-bedroom bungalows to multi-zone hydronic systems. You can even find everything from combo units to conversion kits, all in one spot at The Furnace Outlet.
Choosing the Right Fuel: Gas, Propane, or Oil?
Let’s get this out of the way—fuel type isn’t just about what’s cheapest today. It affects maintenance, long-term costs, availability, and even how your system’s installed.
Natural Gas
If you’ve got access to a gas line, this is the way to go. Gas burns clean, is generally cheaper in the long run, and gives you access to high-efficiency systems that can save you serious money over time. Weil-McLain’s CGa, Ultra, and Evergreen series are all rock-solid choices in this category.
Natural gas is also a popular choice for homeowners who want to take advantage of rebate programs. ENERGY STAR’s rebate finder is a great tool to check what’s available in your zip code.
Propane (LP)
Don’t have a gas line? Propane is a great off-grid alternative. The good news is many gas boilers can be converted to propane with a manufacturer-approved kit. Just make sure you’re using the correct conversion hardware—Weil-McLain offers kits like the KIT-C NG/LP CGi6 S3 to make this easy.
Not sure what propane will cost compared to gas in your area? Use this fuel cost comparison calculator to weigh your options.
Oil
Oil-fired boilers aren’t dead—especially in parts of the country where heating oil is still the norm. Weil-McLain’s WTGO and SGO series offer powerful oil options that hold up year after year. Just be aware that oil systems require a bit more maintenance and tend to be less efficient than modern gas or propane systems.
Understanding Efficiency: AFUE Matters
AFUE stands for Annual Fuel Utilization Efficiency, and it tells you how much of your fuel actually goes into heating your home.
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80% AFUE: For every dollar you spend on fuel, 80 cents becomes heat, and the other 20 cents go up the flue.
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90–95% AFUE: These high-efficiency boilers waste very little fuel and can lead to big savings over time.
If you’re aiming to cut your energy bills and qualify for incentives, look into condensing models like the Weil-McLain Ultra or Evergreen series. They extract more heat from combustion gases by condensing moisture from the exhaust—meaning less wasted energy.
Want to see if you’re eligible for tax credits or utility rebates? The Database of State Incentives for Renewables & Efficiency (DSIRE) is the go-to source.
Get the Size Right: Bigger Isn’t Always Better
One of the most common mistakes I see? Folks buy a boiler that’s way too big for their house. It might seem like “more power” equals “more comfort,” but oversizing leads to short cycling, reduced efficiency, and early system wear.
A Quick Sizing Chart
| Home Size (Sq Ft) | Approx. BTUs Needed |
|---|---|
| 1,000–1,500 | 50,000–70,000 |
| 1,500–2,000 | 70,000–90,000 |
| 2,000–2,500 | 90,000–110,000 |
| 2,500–3,000 | 110,000–130,000 |
But don’t just guess—use a BTU calculator or ask for a Manual J load calculation from a licensed HVAC contractor. Factors like insulation, ceiling height, and number of windows all matter.
Combi Boilers vs. Traditional Systems
If you want a boiler that also provides domestic hot water, consider a combi boiler. These units do double duty, heating both your home and your tap water in one system. For smaller homes or households with moderate water usage, a combi system can be space-saving and efficient.
Weil-McLain’s AquaBalance series offers a reliable combi solution with efficiency ratings over 94%. But if your family tends to use a lot of hot water at once—think multiple showers, laundry, and dishwashing all happening at the same time—you’re better off with a boiler + indirect water heater combo.
Features That Matter (and a Few That Don’t)
Let’s talk features. Not every bell and whistle makes a difference, but there are a few extras worth paying attention to:
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Modulating burners: Adjust output automatically based on demand
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Outdoor reset sensors: Improve efficiency by adjusting boiler output based on the weather
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Zone compatibility: Ideal if you want to control temps in different parts of the home
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Low-water cutoff: Shuts the boiler down if water levels get too low—an essential safety feature
Smart thermostats like the ecobee or Nest can be paired with Weil-McLain systems too, but make sure your installer knows how to integrate them properly.
Installation Costs: What to Expect
The boiler itself might run you anywhere from $1,500 to $4,000, depending on size and features. But the full installed cost—including removal of your old system, new piping, venting, and labor—can range between $4,000 and $10,000.
Factors that affect install cost:
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Size and efficiency of the boiler
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Location (e.g., tight crawlspace vs open basement)
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Type of system (steam vs. hot water)
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Venting upgrades for high-efficiency systems
Hiring a licensed installer is key—especially when dealing with fuel lines, gas pressure, and safety devices. And remember: installation mistakes are the leading cause of performance issues later on.
Conversion Kits and Replacement Parts
One of the reasons I like Weil-McLain so much is their approach to long-term support. They don’t just sell you a boiler and disappear—they back it up with conversion kits, repair parts, and warranty coverage that makes sense.
Planning a propane conversion down the road? Stock a natural gas to LP kit like the KIT-C NG/LP CGA7 S3 now so you’re not scrambling when fuel prices shift. And it never hurts to keep basic spares on hand: igniters, flame sensors, gaskets, and relief valves are the usual suspects.
My Recommendation: Keep It Simple, Keep It Smart
Here’s what I tell most folks in colder states with natural gas access:
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Go with a 90,000–105,000 BTU natural gas model like the Weil-McLain CGa or Evergreen
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Opt for modulating burner and outdoor reset if your budget allows
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Don’t oversize, and get a load calc before you buy
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Use a licensed contractor, not a handyman, for the install
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Buy from a supplier that knows boilers, stocks parts, and stands behind their gear
Final Word from Mike
Boiler systems might seem complicated, but when you break them down, it all comes back to the basics: solid construction, the right size, and a good installer. I’ve worked on enough of these to tell you with confidence—a properly sized Weil-McLain boiler is one of the smartest long-term upgrades you can make to your home.
If you're ready to take the plunge, start by checking out the full selection of Weil-McLain boilers, parts, and accessories. They've got the gear, the kits, and the support to make your heating system one less thing to worry about.
