Getting the Most Out of High-Efficiency Gas Boilers, Part 1: Installation



Here at PB Heat, we pride ourselves on offering our valued installer partners the broadest range of residential and commercial boilers in the industry to meet the comfort needs of any interior space their clients present to them—“from cottage to convention hall.” And our new blog will share insights and answer questions about some of our most popular products to help you best appreciate and understand the benefits Peerless® Boilers can bring to your HVAC contracting business or distributorship.

Today’s post (our first!) is part one in a two-part series about maximizing high-efficiency gas boilers—which, as you’ve likely experienced—are a particularly hot product now both in residential and commercial applications. These incredibly efficient pieces of equipment are excellent as new installs, but also have generated a lot of interest in the retrofit market as consumers search for more efficiency and utility rebates to help lower the cost of the upgrade.   

Let’s take a closer look at how you can achieve successful installation of new high-efficiency gas boilers, specifically in residential and light commercial settings, by concentrating on a few best practices.

Which Gas Boilers are High-Efficiency?

You know that the term “high-efficiency” is applied to equipment that uses less fuel and less water than standard models to achieve the same or better heating outcomes. High-efficiency gas-fired boilers are at least 90% efficient based on annual fuel utilization efficiency (AFUE) ratings, and residential models typically carry the all-important ENERGY STAR designation.

When properly installed and operated, high-efficiency equipment should save its owner money, which is why these boilers are attractive to home and business owners. 

Proper Installation

It may go without saying, but assuring that equipment is carefully and correctly installed according to IO&M manual specifications is imperative for preserving product warranties, as well as creating happy customers. Because this is so important, we make access to our vast library of product information about all of our Peerless Boilers extremely easy for our installer partners. PB Heat also offers a variety of in-person training programs so you can make every installation a successful one. Get to know our resources we provide for our Contractors and Distributors.

The biggest points to consider at install of new gas-fired high-efficiency boilers include the following:

Boiler Sizing

Accurate sizing requires a thorough heat loss calculation, which is something that many installers feel is too time consuming. Additionally, there is a misconception in the industry that because high-efficiency boilers are typically the condensing type and modulate to claim latent heat, they don’t need to be as carefully sized as non-condensing boilers. However, proper sizing is what allows for accurate modulation, which prevents water from heating too quickly and causing short-cycling problems in operation!

There are lots of useful heat loss calculators available today, so you don’t have to do manual math. Whether you’re installing non-condensing or condensing boilers, sizing is equally essential.

Proper Venting

Gas boilers offer the major benefit of not having to be vented through a traditional chimney structure. This fact is one of the many that’s made them so popular. This doesn’t mean that installers shouldn’t pay close attention to venting factors, however.

In fact, it can be argued that venting considerations—which can affect the physical placement of the boiler itself—are more important than ever, as newer modulating boilers with high turndown tend to move less air through the heat exchanger (meaning that products of combustion aren’t necessarily pushed as hard beyond the end of the vent). Always follow the IO&M manual’s venting specifications for best results.

Piping the Boiler

Some installers might argue that boilers with fire tube heat exchangers don’t require primary and secondary (p/s) piping. And they may have preconceived notions about system piping size relative to boiler piping size. It’s important to reiterate that following the IO&M manual to pipe the boiler—instead of relying on prior experience to guide decision-making—is the best thing you can do. The best boiler manufacturers in the industry take great care in constructing our manuals to ensure the best installation outcomes and remove any guesswork—you can use our documentation with confidence.

Setting Zone Controls

“Zoning” a home or light commercial facility for the most efficient boiler operation is both an art and a science. The goal with setting up different heating zones is to assure that the boiler will rarely have to operate with the fan blasting at its maximum RPM. This process is easy to accomplish with the state-of-the-art controls built into modern boilers. Again, the IO&M manual will be extremely helpful in zoning, though you may also want to connect with technical service at your boiler’s manufacturer with specific questions about heating zones.

Optimal Start-up

Once all boiler components are installed, it’s important to start strong, whether you’re working with natural gas or LP, you’ll need to assure that incoming gas pressure is appropriate. Even with other gas appliances running, this pressure needs to be higher than the minimum specification for the boiler.

Test combustion and be sure that oxygen (O2) is adequate for both low fire and high fire operation—we probably sound like a broken record by now, but your IO&M manual will give you the proper O2 settings. Don’t forget, though, that low fire O2 must be greater than or equal to the high fire O2.

Why Peerless High-Efficiency Gas Boilers?

Obviously, today’s post just scratches the surface of installation tips for getting the most out of high-efficiency gas boilers. But we hope you recognize how PB Heat goes above and beyond to make a successful install process easy for our professional industry partners.

Peerless Boilers are indeed America’s Best Built Boilers, but we’re not content to leave it at that. We offer comprehensive training opportunities and convenient access to our documentation right here on PeerlessBoilers.com so you can install our boilers with the highest confidence. Curious about all the ways Peerless Boilers are a fantastic solution for your customers? Get in touch with us now.