Best Residential Boilers for Radiant Floor Heat 2024

Here’s the list of the best residential boilers for radiant floor heating systems. The list starts with models in the lower efficiency ratings and ranges to high-efficiency radiant floor heating boilers.

  • Weil-McLain CGi Gas Boiler Series 3
  • Peerless Boiler MI Series
  • New Yorker CGS-C Gas Boiler
  • Buderus G234X Gas Boiler
  • Peerless WB-90 Oil Boiler
  • Utica Boiler UB90-100 IV Series Gas Boilers
  • Navien NHB Tankless Gas Boiler
  • Laars Mascot FT
  • Slant Fin CHS Gas Boilers

The specifications, features and the cost of each model are discussed for each.

If you’re new to boiler systems, you might enjoy our comprehensive Boiler Buying Guide that discusses boiler types, performance, cost and choosing the right boiler for your needs.

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Best Radiant Floor Heat Boilers

We’ve included tips for choosing a boiler that will best suit your purposes.

Note: In boiler literature, the term MBH is used for 1,000 BTU/hour. A 100 MBH boiler has an input of 100,000 BTU/hour.

Here are the best boilers for radiant floor heat from least efficient to most. In general, the lower the efficiency, the lower the boiler cost, but the higher the operating cost will be. And vice versa. That’s the trade-off, just as if you were comparing 80% furnaces to those in the 90% to 97% range.

Weil-McLain CGi Series 3 Gas Boiler

This is a traditional tank-style, floor-mounted workhorse boiler built with cast iron where it is needed most. Its efficiency falls in the average range, but it is one of the most reliable, long-lasting boilers available. They are rated for residential and light-commercial use. The CGi Series 3 boilers are made in the United States.

Features: The CGi boiler series, also called the Weil McClain Gold Series boiler, is a hot water boiler. It is produced in 7 models with a capacity range from 50 MBH to 233 MBH input. They’re ideal for any size heat system, from serving just one or two rooms to an entire large home.

The efficiencies range from 82.7% AFUE to 85.1%. Both natural gas (NG) and propane (LP) boilers are available in each size. A 24-volt thermostat is required.

The internal construction is cast iron with a steel base for outstanding durability. The Weil McClain CGi boilers can be installed for natural draft venting or direct exhaust venting.

Price: Weil McLain CGi Series 3 boiler price is $1,700 to $3,100 for the unit. Installation supplies and labor are extra.

Weil McLain makes 10 series of boilers including tankless boilers and combi boilers that can be used in hydronic/radiant heat floor systems. Browse them all in our Weil McLain Boiler Buying Guide with specs, features and prices.

Best fit: You’ll like this boiler if you prefer the lower upfront cost of a non-condensing unit and want a reliable, traditional boiler instead of a tankless boiler.

The difference between condensing and non-condensing boilers is explained in our Boiler Buying Guide.

Peerless Boiler MI Gas Boiler Series

The Peerless Boiler MI Series is comparable to the Weil McLain CGi Series. The internal construction is cast iron, and the efficiency is very good for a non-condensing gas boiler. It’s a 35-year boiler when maintained.

Features: The efficiency of this series is 82% AFUE for the largest boilers and 85% for smaller models. It’s produced in NG and LP gas boilers. Propane boilers cost $200-$300 more than natural gas versions.

The system makes hot water, not steam. The units are complete – no additional equipment is required – and ready to connect to your hydronic in-floor heating system.

The seven (7) PB/Peerless Boiler MI Series boiler models, MI-03 to MI-09, range from 70-260 MBH in 35 MBH increments. There’s one for every size radiant floor heating boiler system.

Price: Cost of the boiler unit is $1,875 to $4,300. Installation and necessary supplies are extra.

Best Fit: The Peerless Boiler MI-03 to MI-09 Series are well built and durable. We’re impressed with the cast iron construction and heavy-duty welds. Warranties are above average.

Because efficiency drops as the units get larger, we recommend the Peerless MI Series when the radiant floor system is less than 2,000 square feet. It’s still solid, but less efficient, for larger homes.

The cost of the boiler is less than a comparable high-efficiency condensing unit, and long-term maintenance and repair costs tend to be lower. That’s why we recommend non-condensing units. The downside is that operating costs are higher, since the efficiency is lower.

New Yorker CGS-C Gas Boiler

If you prefer the power of steam to hot water, the New Yorker CGS-C Series is a very good choice. It’s available in a wide range of sizes for applications from small to large.

Features: The CGS Series is built with a cast iron heat exchanger and stainless steel burners that won’t corrode in the acidic combustion gases. The heat exchanger is covered by a limited lifetime warranty. The general parts warranty is 10 years.

This is a single-stage boiler, so the design is simple. That means fewer mechanical failures and repairs, if needed, that are less expensive. It features electronic ignition for reliable starting, and burns natural gas or liquid propane.

The efficiency of this line of boilers is just 82%, but the offset is lower cost and longer life than most condensing boilers with 95% efficiency.

Models made range from about 70 to 240 MBH of input. Output is MBH multiplied by efficiency.

Price: Depending on the range of models available from the dealer or seller you choose, cost will be $1,650 to $3,050.

Best fit: Due to the lower efficiency, we recommend this boiler for moderate and warm climates rather than cold northern regions. It’s a solid performer for radiant floor heat and can be used for other applications such as baseboard heat or heating water for a pool or spa.

Also, it is not an ultra low-NOx unit, so might not be usable where strict emissions standards are in place.

Buderus G234X Gas Boiler

The Buderus G234X is also branded the Logano G234X. We’ve included it because it is one of the best large-capacity boilers on the market. Input capacity is 160 to 266 MBH – and output is up to 85% of that.

The G334X is a boiler designed for even larger residential and commercial applications with models with input up to 399 MBH.

Features: The G234X is a hot water boiler is fitted to burn natural gas but can easily be converted for propane when installed. Efficiency is good at 85% AFUE.

The construction is cast iron for longer life, while the burners are stainless steel. More than 3 inches of insulation protects against standby heat loss, and the premixed burner technology reduces emissions.

Price: $2,950-$4,000. There are four models in the G234X Series.

Best fit: This boiler is designed for use in large homes and small commercial offices. The efficiency is good, but not great, suitable for most climates.

Peerless WB-90 Oil Boiler

This is a mid-range oil boiler that offers excellent value for the money. We think it’s one of the best oil boilers for radiant floor heat. Efficiency is excellent for an oil-burning product. Construction is heavy duty for long life. It’s suitable for a range of applications.

Features: The WB-90 Series burns heating oil and has efficiency up to 90%. These are Energy Star rated boilers. The two models have output capacities of 111 and 160 MBH.

The Carlin flame retention burners are considered among the best in the industry.

Price: $4,875-$5,500. The cost is due to the excellent efficiency, large capacity and oil-burning construction.

Best fit: As you can see from the price, oil boilers are the most expensive type. This is one of the reasons that they are only used in the Northeast where LP and natural gas aren’t as plentiful as they are in most regions.

These boilers offer medium and large capacity for mid-size to large homes and some light commercial use too.

Utica Boiler UB90-100 IV Series Gas Boilers

This is a quality boiler in the mid-efficiency range, a good mix of lower cost than condensing boilers but reasonable operating costs too. The series is known for trouble-free durability.

Features: There are three models in small to medium sizes, 50, 75 and 100 MBH. Top efficiency is 90% AFUE. The efficiency level meets Energy Star requirements. The unit fires with natural gas or liquid propane when the proper gas port is installed.

The construction of the heat exchanger is cast aluminum, so the resistance to corrosion is superior to steel. It’s on par with stainless steel. The premix burner is made from stainless.

The hot surface ignition (HSI) is dependable. Both high heat limit and low water cut off controls protect the unit from damage due to overheating. Utica Boilers backs the units with a 15-year warranty that is above average for the industry.

Price: $3,300-$3,800. There isn’t a big difference in price between the three models. It’s still a good idea to properly size your boiler for the size of your in-floor hydronic system. If you intend to add to your system, it makes sense to buy up.

Best fit: This is a very versatile boiler suited to most homes less than 3,000 square feet. It’s also hard-working boiler suitable for light commercial applications like office space or a small shop.

Navien NHB Tankless Gas Boiler

This is a tankless boiler with tremendous efficiency driven by condensing technology. A condensing boiler uses hot exhaust gases to preheat incoming water, so the burners use less fuel getting it to the proper temperature.

Navien is known for tankless water heaters, and the technology translates very well to the hydronic infloor heating market.

Features: The Navien NHB Series is 95% efficient and Energy Star rated. Four models are 55, 80, 110 and 150 MBH. This unit has an adjustable heat capacity, so you won’t waste energy overheating water for your system. The NHB Series has a 15:1 turn-down ratio. The unit is equipped for natural gas but is easily converted for LP gas. The heat exchanger is stainless steel.

Despite being tankless, this unit can supply enough hot water for in-floor heating and domestic hot water, as long as you have it sized properly for the demand. Freeze protection means you can install the unit in unheated space indoors or outdoors. For larger applications, multiple units can be ganged together – up to 16 total, not typical for residential use.

Navien backs the boilers with a 5-year part and 15-year heat exchanger warranty.

Price: $1,785 to $2,050 for the unit.

Best fit: If you have had success with Navien tankless water heaters and like they’re ease of use, the NHB is quite similar. It also makes sense if you have limited space for a boiler or must install it outdoors.

Laars Mascot FT

These are high-efficiency combi boilers that can heat your floor system and provide domestic hot water at all your taps. Your options are wall-mount tankless boilers and floor-mount tank-style boilers.

Features: This is a combination (combi) boiler that produces hot water for radiant floor heating and domestic hot water (DHW).

Both wall-mount and floor models can be bought in natural gas or propane versions. Both styles are equipped with a small auxiliary tank of water that is kept hot for immediate use in radiant floor heat or domestic hot water heat. This is a feature that sets this series apart from the competition.

There are two models: 140 and 199 MBH. Efficiency is 95% using condensing technology that makes the most of hot combustion exhaust. The high efficiency means that multiple vent styles, including PVC and polypropylene side venting, are possible.

The units are built with an aluminum core heating tubes with stainless steel sleeves. The combination ensures excellent heat transfer and resistance to corrosion. Modulation, or turn-down, on these units is 10:1, so you’ll create only the heat you need.

The Laars Mascot FT Series is low NOx, so can be installed where emissions restrictions are in place.

Price: $1,725-$2,200 for wall units. Floor units, which are new to the series, are about $1,000 more per model.

Best fit: The Laars Mascot FT Series is designed for medium to large homes and small commercial installations. The wall-mount and floor-mount models plus choosing either a tankless boiler or a tank-style boiler give you options. Discuss them with an experienced boiler contractor to choose the best boiler for your purposes.

Slant Fin CHS Gas Boilers

Slant Fin is one of the top five boiler manufacturers, and the CHS Series is one of the best of the brand.

Features: These up to 95% AFUE. The CHS Series are condensing boilers, so achieve an efficiency of boilers are made in a wide range: 85, 110, 154, 175, 200, 250, 340 and 399MBH.

The CHS Series is low-NOx for regions with strict emissions standards. It uses a fire tube design like the other condensing series in this list. The modulating combustion system is the most efficient type available on the market.

Slant Fin backs the Slant Fin CHS line with a 15-year warranty.

Price: $2,625-$8,600 for units in this wide range of models.

Best fit: The Slant Fin CHS Series is ideal for anyone that wants the lowest operating costs of any boiler. The wide range of models is right for homes from small to very large. These units work for light commercial settings too.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.

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