Weil-McLain Boiler Review - Has Weil-McLain Lost Its Grasp on the Gas Boiler Industry?

Weil-McLain boilers have had a key roll in the boiler and indirect fired water heater industry since its inception in 1881.  People often write us to ask questions about their boilers and other products, so today we will take a more in-depth look at this company in our Weil-McLain boiler review.  Those who have read our articles before know that we are a U.S. Veteran-Owned heating and air conditioning company that has built a reputation for giving honest, frank answers to peoples’ HVAC questions; this article will be no different.  In this article, we will discuss a few different topics, including the history of Weil-McLain boilers, and how a boiler works.  We’ll then take a more focused look through a Weil-McLain boiler review of features, cost, and other important information you need to make the right decision.


Weil-McLain Boiler Review – The History

Weil-McClain Boiler Review

Weil-McLain was founded in 1881, and is well known in both the residential and commercial HVAC industry for their hydronic equipment (hydronic meaning that they use circulated hot water to heat your home or building).  Started by the Weil brothers in Chicago, the company later acquired the J.H. McLain Company in 1918, subsequently changing their name to Weil-McLain.

Why does this matter?  It doesn’t, but it makes me sound smarter than I actually am, and I’m okay with that.

Weil-McLain Makes Boilers.  Great…What is a Boiler?

Weil-McLain manufactures boilers, not furnaces.  Whereas a furnace works by burning a combustible liquid or gas (usually natural gas or propane) inside a heat exchanger heating the air inside your home or office directly, a boiler operates using a different principle altogether.

A boiler operates a little bit differently in that a boiler uses the combustable gases to heat a body of water (or a mixture of water and anti-freeze) just like your hot water heater.  It then circulates the heated water through a heat exchanger, which in turn, heats the air inside of your home.

The biggest advantage that a boiler provides over a furnace is the ability to transport heat over long distances, allowing the user to place the boiler in one location, and the element to be heated – your home or office – in another.

Heating your home in this manner has several advantages, the most notable of which is the ability to transport this heat over long distances.  For instance, if you had a furnace on your roof, you’d have to somehow transport the air inside of your home onto the roof, heat it, then transfer it back to your home.

In doing so, you’d be losing heat along the way that could instead be used to warm your home.  While this is not a big deal in a modest 1,200 square foot condo, an 8,000 square foot car dealership might have trouble moving that much air to the roof and back.

With a boiler, however, you can heat water on your roof (or another location), then pump it down to a series of heat exchangers located inside of your home or office (since water is very good at maintaining and transporting heat).  You can think of this as working similarly to the radiator in your car, which transports heat away from your engine and disburses it into the outside air, cooling the engine.  Only with a boiler, your aim is to heat the air inside of your home or office.

How Weil-McLain Boilers Are Measured

There are two important numbers that you will have to become aquatinted with when it comes to shopping for your Weil-McLain boiler: MBH and AFUE.


MBH is an abbreviation for Thousand BTU’s per Hour.

But Tim, wouldn’t that be TBH?  Well, yes, it would…but engineers like to be funny (mainly because nothing about their job is fun…oh yea, I went there), so they decided to replace “thousand,” with the latin word “Mille,” which also means thousand.  Romans are cooler than Brits, hence the Roman-Numeral “M” in the acronym MBH.

1 MBH = 1,000 BTUs/hr

Why does this matter?  Well, because this is how Weil-McLain boilers are sized.  So, a 299 MBH Weil-McLain boiler would be capable of producing 299,000 BTUs of heating power every hour, or around 32-times the power of your gas-stove.


A Weil-McLain boiler measures its efficiency the same way as a furnace, using Annual Fuel Utilization Efficiency (AFUE).  Simply put, an AFUE rating is a direct measurement of what percentage of your fuel is being transferred into heating your home.

So, a Weil-McLain boiler that has an AFUE rating of 95% AFUE would transfer 95% of the fuel burned directly into heating your home or office, and 5% would be lost as thermal waste through the exhaust flue.  More on this can be found here:

Weil-McLain Boiler Review - Has Weil-McLain Lost Its Grasp on the Gas Boiler Industry?

Weil-McLain Evergreen Gas Boiler

Weil-McLain Boiler Review of Features and Specifications

Now that we are all experts on boilers, let’s get started on our Weil-McLain boiler review.   To start, we will look at the features and specifications of some popular Weil-McLain boilers.  Don’t worry, we will get into some hard-core evaluations later…just familiarize yourself with a few of their products.

The Weil-McLain Evergreen Gas Boiler

Average Cost: $3,993

The Weil-McLain Evergreen Gas Boiler is a workhorse of the Weil-McLain catalog.  One of the things that I have always admired about Weil-McLain products is that they are sturdy and well made.

Actually, they are made right here in the U.S., with factories in Michigan City, Indiana, and Eden, North Carolina.

Below is a list of the features and specifications for this unit.  Most of these you don’t need to know (unless you’re an engineer…nerd).  The ones that are important to a layman are highlighted in red: stainless steel heat exchanger, the sizes it’s available in, and the AFUE (efficiency) rating:

  • Stainless Steel Fire Tube Heat Exchanger with non-metallic base
  • Floor Standing Boiler with optional wall mount kit
  • Sizes 220MBH, 299MBH, 399MBH
  • Modulating Condensing Boiler with 10:1 Turndown
  • 95% AFUE (220/299); 96.5% Combustion Efficiency (399)
  • Up to 8 Multiple Boiler Control with lead/lag rotation
  • 4 Pump/Auxiliary Outputs (Example: 1 boiler loop pump +3 zone pumps)
  • Each input can be assigned to a priority (Up to 3 Priorities)
  • Multiple Inputs can be assigned one priority (Zone Based Control)
  • 0-10 Volt Input (modulation or set point)
  • Configurable Auxiliary Input/Output System
  • All Lag Boiler Inputs and Output can be used
  • Boiler Circulator Included




Weil-McLain AquaBalance Wall Mount Gas Combi Boiler

Average Cost: $5,119

Weil-McLain boiler - AquaBalance Wall Mount Gas Boiler


The Weil-McLain AquaBalance Wall Mount Gas Boiler is pretty top-notch, and is designed to be mounted directly on your wall.  It’s ideal for garage placement without taking up too much room for your Porsche (or your Leaf, if you are a Californian).

Again, don’t focus on most of the list unless that’s your thing…I just kept it in there for the nerds (which is probably you).  The important parts are highlighted in red: AFUE, natural gas or propane operation, thin & compact design, quiet operation, and a heavy-duty heat exchanger.

  • 94.4% AFUE – low fuel usage, saves energy
  • Natural or Propane (LP) gas operation – factory shipped as NG, optional LP conversion kit
  • 10-to-1 turn down ratio – precisely matches minimal energy usage to the immediate system need
  • Compact design – increases placement options
  • Heavy gauge insulated jacket – provides quiet operation
  • Low NOx rated – low emissions level achieved South Coast certification
  • Single tube, large diameter, ASME certified 316L Stainless Steel heat exchanger
  • Pre-wired, plug-in ready electrical design
  • Contractor friendly removable sides – makes service clean and easy
  • Internal 3-speed Grundfos circulator
  • Wall mounting bracket and hardware
  • Commercial grade 120V power cord with 3 prong plug
  • Unique 3-in-1 vent adapter – approved to accept PVC, CPVC, SS or PP vent materials
  • Multiple vent options – direct vent with 2 pipes or concentric, through sidewall or roof
  • Internal condensate trap
  • Water treatment – inhibitor and test kit

Weil-McLain Boiler Consumer Reviews

Continuing our Weil-McLain boiler review, we’ll take a look at consumer reviews.  Now, if you’ve read some of our articles before, then you know how I feel about consumer reviews…well, they are written by consumers, which are typically whiny and ill-informed (kidding).  But, to be fair, there is one problem with consumer reviews…

Consumers who like to Yelp, or use other review sites which cater primarily to the restaurant scene, have no problem getting online and raving about their favorite pizza join.  Or, if the pizza stinks, they tell you that too.  As such, restaurant reviews, in general, are pretty reliable.  Here’s the problem…boilers and other HVAC equipment are not restaurants.

People will typically only get online to write a consumer review of an HVAC manufacturing company like Weil-McLain boilers if they are ticked off about something. Think about it…if you install a new boiler and it works great, what are the chances of you getting online and writing Weil-McLain a fantastic review?  Not very good, right? But, if you had problems with it, would you get online and write a review then?  Of course you would!

However, if you think about it, that’s kind of like getting online and writing a scathing review of the cheese company that supplies the cheese to the pizza company; it doesn’t make much sense.  So listen up…reviews of HVAC contractors are typically reliable (except for Yelp because they seem to edit company reviews based on membership), but reviews of manufacturers like Weil-McLain boilers should be taken with a grain of salt…no one takes the time to write a good review about a manufacturer.

In our experience, around 90% of all problems with boilers and other HVAC components can be traced back to improper installation.  That’s scary, isn’t it?  Just realize that who you get to install your Weil-McLain boiler is more important than any other thing you will research, including the brand that you choose!

The Consumer Reviews of Weil-McLain Boilers

Weil-McLain boiler review - furnace compare.com

Weil-McLain Boiler Review c/o furnacecompare

According to review sites like FurnaceCompare, Weil-McLain boilers only scored about a 3 out of 5 with nearly 200 customer reviews.  Problems sited include reliability and premature failure.  However, this same site also rated Lennox at number one, so if there is anything that should make you take a step back, that’s it (we aren’t fans of Lennox due to their poor logistics chain, and feel that they are grossly overprices for the value received).

Again, all I’m giving you are the cold, hard facts.  It’s your decision to make, but I can tell you that this is not an accurate representation of the value received from Weil-McLain.  I, personally, would take a Weil-McLain boiler over a Lennox any day of the week, and twice on Sunday.  Of course, I know how to install a boiler, so maybe that helps…

Again, it is important to note that there aren’t too many HVAC contractors out there that know how to install a boiler properly, so take these consumer reviews with a grain of salt if you can…even a Porsche engine will fail if it’s installed improperly!

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A Note About Weil-McLain Boiler Cost

We’ve listed a few average prices in the previous section, but it is important to note that Weil-McLain boilers (or boilers in general, for that matter) are going to be a bit more expensive than your average furnace.  That is because they have a more rugged construction, and are harder to install.

Additionally, they are more complex than a furnace, so if your contractor comes out and gives you a number that is more expensive than you had originally thought, just bear that in mind.  It doesn’t mean that he is ripping you off (although it could be…who knows these days?).

Final Thoughts on Our Weil-McLain Boiler Review

Boilers are fantastic pieces of technology, and I hope that our Weil-McLain boiler review has shown you a little bit more about the company and their products.  Additionally, take consumer reviews of manufacturers with a healthy dose of skepticism.  People love to get online and write bad reviews when they are ticked off, but will rarely take the time to write a good review for a manufacturer like Weil-McLain.  Good luck on your Weil-McLain boiler purchase, should you decide to go that way, and we wish you the best of luck on your upcoming project!  If you live in southern California, you might be in our service area; click below for more information.


Tim K.
About the author
Tim K.

The University of Virginia - 2005 / The Wharton School of Finance - 2016 / U.S. Naval Aviator 2005-2015. At All Systems Mechanical air conditioning and heating, we believe that the experience our clients have is every bit as important as the products they receive. Simply put, our results speak for themselves, and we'd be happy to help. If you're in the market for a new AC or furnace, make sure that you get a fair price! Try our online calculator; click the tab on the top of this page for more information.

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