Top-rated boiler installation pros.

Best boiler installation pros near Saint John, MO

Enter your zip and get matched with up to 5 pros

TRUSTED BY SAINT JOHN, MO HOMEOWNERS

  • Average homeowner rating star icon4.5
    Average homeowner rating
  • Verified reviews icon1.7k+
    Verified boiler installation services reviews

Top-Rated Boiler installation pros in Saint John - Updated Nov 2026

Avatar for SmartHouse Heating & Cooling
SmartHouse Heating & Cooling
4.7(
593
)
Boiler or Radiator Heating System - Install or ReplaceElectric Boiler or Radiator Heating System - InstallGas Boiler or Radiator Heating System - Install+3 more

Serving Saint John, MO and surrounding areas

Approved

In business since 1947

Free estimates

Emergency services offered

"Marc spent a good amount of time gathering information and explained everything in detail. He readily answered all of my questions and generated an in-depth report that made my decision pretty easy. His installation crew was very professional thorough and courteous. I’m very happy with my decision and the completed project."
Old boiler being removed
A Manual-J load calculation is performed to determine the precise amount of heating and cooling needed for each space.
Installing a Mitsubishi Hyper Heat Mini Split System to Heat and Cool this Sunroom Addition.
Mitsubishi outdoor unit installed on rooftop to heat and cool 3rd floor of this St. Louis City home.
Daikin FIT Heat Pump Installed in University City Home

+106

Response time2 days
3 neighbors recently requested a quote
Recommended by91%of homeowners
American Airtemp LLC
New to Angi
Gas Boiler or Radiator Heating System - Install - For Business

Serving Saint John, MO and surrounding areas

Approved

In business since 2008

Credit card accepted

Offers commercial services

American Airtemp LLC is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests and make their concerns the basis of our business. \n

Response time10 mins
Response rate100%
Avatar for The Gutter Pros
The Gutter Pros
4.5(
28
)
Boiler or Radiator Heating System - Install or ReplaceElectric Boiler or Radiator Heating System - InstallGas Boiler or Radiator Heating System - Install+3 more

Serving Saint John, MO and surrounding areas

In business since 2006

Free estimates

Emergency services offered

"They were absolutely wonderful. They had previously come 3 or 4 times for repairs on the old furnace and only charged me once. The other times they did it for free. They were here for 2 days to do the installation. The new system is very energy efficient. I shopped around and got a very good price. They were very punctual and organized in terms of scheduling. They were here when they said. They were very professional in their explanations about the heating systems. I had a lot of questions and they very patiently answered all my questions. They gave me a lot of options to choose from. They are a totally reliable company. They cleaned up everything and they were very professional. They came when they said. The owner even called and came back a week later to check to see if everything was okay. They wouldn't take any money until I had the system running for a whole week and was satisfied."
Nearing installation completion, Amana S Series is paving the way!
The Team!
Preparing installation of the new, slim unit
These units, just like all the others, require a professional to install.  They are high-tech units and are very impressive.
Additional Photos

+14

Recommended by84%of homeowners
Avatar for Preferred HVAC Services
Preferred HVAC Services
5.0(
9
)
Boiler or Radiator Heating System - Install or ReplaceElectric Boiler or Radiator Heating System - InstallGas Boiler or Radiator Heating System - Install+3 more

Serving Saint John, MO and surrounding areas

In business since 2020

Emergency services offered

Credit card accepted

"Last December, on one Friday early evening, I noticed my heating system was not working and it was very cold. I called PHCS services and they sent a technician Saturday morning to diagnose the issue. FYI, I am a handyman and fix a lot of things around my house, but I don't have the right tools for this service and don't like to do anything with gas pipes. I watched the technician doing his work and realized he is an expert. He checked everything and was able to detect that the gas valve was the culprit. He also recommended replacing the pressure switch. He explained to me what was happening and even showed me how the failure was triggered. In addition, he checked the whole system and even recommended me to install two carbon monoxide detectors, one by the heating system and one on the first floor by the bedrooms. I haven't bought and installed them yet - mea culpa. He didn't have the parts in his truck, but he said, Monday morning another technician would come with the parts and replace them. Before leaving, he explained to me that I could turn on the heating system for a few minutes to heat the house until the pressure valve would fail. After that, I would need to wait sometime and then could turn on the system again. I followed his instructions and was able to stay and sleep in a warm house on Saturday and Sunday. As promised, Monday morning, another technician came over, replaced the parts, and made the necessary calibrations. Few days later, I received an email with the bill, which was very reasonable, and so far my heating system is working like a champ. It is nice to know that there are still good and honest people in this world."
IWave Install
new ac
tstat after completion
IWave Install
micron reading for AC

+54

Recommended by100%of homeowners
...
Showing 1-10 of 60
Install Boiler FAQs, answered by experts

The average cost to replace or install a new HVAC system is around $7,500. However, the price can range from $5,000 to $12,500, depending on factors like the size of your home, the type and brand of the unit, and your specific heating and cooling needs. If you only need to replace certain components, the cost will be lower; for example, a new AC unit can cost between $2,200 and $5,500, while a new furnace costs $3,200 to $6,000. If additional work like new ductwork is required, the total cost could be as high as $22,000. It's best to contact a local HVAC company for an accurate quote.

Most home boilers will need an expansion tank. That’s because these boilers are closed-loop systems, where the water is trapped. An expansion tank is needed when the boiler heats the water and it expands, allowing air to condense in the tank to make room for the water. Other types of boilers don’t use an expansion tank, such as traditional steam boilers, but these aren’t as common. And hot water tanks may be able to use a pressure release valve instead. When in doubt, call in a pro to take a look.

Scale from hard water is hard to diagnose until it starts causing problems. If your area has particularly hard water, that’s most likely what your boiler is using. If scale build-up becomes a problem, it starts to cause decreased flow and heating, and eventually, valve failures as valves become blocked. Let boiler professionals know if you’re worried about scale and they can offer advice or implement a solution.

Yes, most municipalities require a permit for propane boiler installation to ensure safety and code compliance. Permit fees vary by location and are often included in your installer’s quote, as they’ll handle the permitting process. Ensure that you always check local regulations before starting your project to avoid fines or delays.

The cost to install a steam boiler varies depending on the type, fuel used, and your house size. The average cost to install a boiler is $5,900. You could spend $2,000 for a basic electrical steam boiler or up to $9,000 for a high-efficiency oil-burning steam boiler. Boiler installation is a job that’s best left for professionals to complete, and, in some states, only licensed installers can legally complete the job.

The Saint John, MO homeowners’ guide to boiler installation services

From average costs to expert advice, get all the answers you need to get your job done.