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Best boiler installation pros near Alton, IL

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TRUSTED BY ALTON, IL HOMEOWNERS

  • Average homeowner rating star icon4.3
    Average homeowner rating
  • Verified reviews icon374
    Verified boiler installation services reviews

Top-Rated Boiler installation pros in Alton - Updated Nov 2026

Tiger Plumbing, Heating, Air Conditioning, & Electrical Services
3.4(
357
)
Electric Boiler or Radiator Heating System - InstallGas Boiler or Radiator Heating System - Install

Serving Alton, IL and surrounding areas

Approved (Corporate)

In business since 1993

Free estimates

Emergency services offered

"I have used the company many times. Two technicians came out for the tuneup and completed the job in about 2 hours. The company has also replaced the furnace and AC in the past. They are very thorough and professional. The staff is also very friendly and available for service. I am a member of their club which makes them easily accessible to me."
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+5

308 neighbors recently requested a quote
Recommended by73%of homeowners
American Airtemp LLC
New to Angi
Gas Boiler or Radiator Heating System - Install - For Business

Serving Alton, IL 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 Triplett Mechanical Services
Triplett Mechanical Services
4.9(
35
)
Gas Boiler or Radiator Heating System - Install - For Business

Serving Alton, IL and surrounding areas

In business since 1995

Free estimates

Emergency services offered

At Triplett Mechanical Services, we have been satisfying customers HVAC needs for over 13 years. Although we are a small company, we are quick to respond, and very competitive in our pricing. The work we do in our chosen trade is extremely well done and our materials are of the highest quality as well. Perhaps the thing we are proudest of is our ability to have a clean work environment at all times. Naturally, our desire is to always completely meet or exceed your needs as a consumer. When you have HVAC needs, we can fix it and in a timely fashion.

Response time10 hrs
Recommended by94%of homeowners
JMW Mechanical Heating & Cooling
4.7(
15
)
Boiler or Radiator Heating System - Install or ReplaceElectric Boiler or Radiator Heating System - InstallGas Boiler or Radiator Heating System - Install+3 more

Serving Alton, IL and surrounding areas

Credit card accepted

"Very professional company. He returned my call promptly, came out to install my water heater in timely manner, and followed up after job was finished. He went above and beyond to make sure everything was up to code. I have no negative feedback for this provider."
Recommended by92%of homeowners
Avatar for Spengler Plumbing, Heating and Cooling
Spengler Plumbing, Heating and Cooling
3.8(
75
)
Boiler or Radiator Heating System - Install or ReplaceElectric Boiler or Radiator Heating System - InstallGas Boiler or Radiator Heating System - Install+3 more

Serving Alton, IL and surrounding areas

In business since 1971

Emergency services offered

Credit card accepted

"The installation itself was very good.  I noticed the old tank leaking at 2:00pm Tuesday - was replaced by 2:00pm Wednesday.  They came out quickly to provide a bid and settled on Spengler that night and they were here at 8:30am the next morning.  The installer was friendly and considerate - top notch.  The only knock will be the salesman himself - a bit high pressure not a big deal because we knew we were going to use them after the research we had done.  He was here for nearly 3 hours looking things over then writing his bid then discussing with us his bid then sitting in his truck while we reviewed the bid then finally signing the contract.  The most disappointing was the discussing about their calendar - he wanted to be sure my wife knew which month he was "featured" - really - cmon man!
"
Recommended by68%of homeowners
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Install Boiler FAQs, answered by experts

It can take anywhere from four hours to three days to replace a boiler with a new one. How long your particular boiler installation takes will depend on whether you need a gas line installed and if you’re switching to a new boiler system. 

Replacing a combination boiler or standard boiler with the same system should only take four to six hours. Meanwhile, switching from a conventional boiler system to a combination boiler system could take a few days.

If you have a closed-system boiler that requires an expansion tank, you cannot safely operate it without one, as this risks extensive damage or even explosions. You must find a way to make room for the installation. Options include repositioning the boiler, rerouting the boiler piping to a more open area, or performing minor remodeling to create the necessary space. If you are unsure whether your boiler needs an expansion tank or how to best accommodate one, it's recommended to have a local heating service professional assess the situation. They can confirm the requirement and suggest the most practical solution.

Overall, heating your home with an oil furnace tends to be less expensive than heating your home with an electric heating system. Oil heating systems stay warm for longer periods of time without drawing a constant electrical current to maintain a temperature. Plus, heating oil systems typically have a longer lifespan and lower price tag than their electrical counterparts, resulting in short- and long-term savings.

The best way to compare HVAC quotes is getting a few detailed quotes from local companies with good reputations. Then, go over the quotes line by line. Protect yourself by insisting on in-person estimates that include equipment manufacturer names, model numbers, SEER ratings, amounts and numbers of materials, details of warranties on equipment and labor, and other specifics. 

Knowing the exact equipment and materials is the only way that you can fairly compare quotes. Quotes that are much lower than others can be a sign that the company isn’t providing the best quality service or materials.

If you go to turn it counterclockwise and it won’t turn anymore, it’s open. Like most other valves, you should be able to turn a radiator valve counterclockwise (to the left) to open it and clockwise (right) to close it. To close a radiator valve, turn it clockwise until you meet some resistance and can’t turn anymore, but do so carefully to avoid breaking the valve.

The Alton, IL homeowners’ guide to boiler installation services

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