Boilers · radiators · steam and hot water
Boiler repair and installation in Milwaukee
A lot of older Milwaukee homes still heat with hot-water or steam boilers, and not every contractor works on them. We work on hot-water and steam systems every week, from Bay View bungalows to Wauwatosa colonials.
★ 4.9 on Google · 440+ reviews | BBB A+ Accredited | Wisconsin-registered HVAC contractor | Veteran-owned | Since 2014
Flat-rate price first
You approve the number before work starts
24/7 emergency line
Rings Mike’s cell, nights and weekends
Free replacement estimates
Written proposal with options, same day
Hot water and steam
Every boiler brand serviced and repaired
Boiler repair: no heat, cold radiators, banging pipes
Boiler problems look mysterious and usually are not. A boiler that fires but leaves the house cold typically has a failed circulator pump, a stuck zone valve, air in the lines or a low-water cutoff tripping. Banging and gurgling point to trapped air, failed steam vents or a flooded wet return. Leaks come from relief valves, expansion tanks, pump flanges and old fittings. We find the actual cause, show you, and quote a flat-rate repair before we start.
- Circulators, zone valves, aquastats, expansion tanks, relief valves, low-water cutoffs, ignition and gas valve repairs
- Steam systems: main vents, radiator vents, traps, pressuretrols, near-boiler piping, water-line and skimming problems
- Radiator and baseboard balancing so every room heats, not just the ones nearest the boiler
- Annual boiler service with combustion analysis to keep it safe and efficient
- Every repair guaranteed for one year, parts and labor
Boiler replacement, sized by the radiation, not the square footage
A replacement boiler must match the radiators and piping it feeds. Sizing by square footage, which is how most quick quotes are done, usually produces an oversized boiler that short-cycles and wastes gas. We count the radiation, check the piping and venting, and propose options in writing: a reliable cast-iron boiler, a high-efficiency condensing boiler, or a combi unit that also replaces the water heater.
- Free in-home estimate with a written proposal the same day
- Permit and inspection included in the written price
- Zoning, outdoor reset and smart thermostats that actually work with hot-water heat
- Financing on approved credit, and Focus on Energy instant discounts on qualifying high-efficiency boilers
Recent boiler jobs
Photos from our own jobs, not stock images.
Emergency right now? Call or text 414-595-5175, any hour.
Request service or a free replacement estimate
We call you back during business hours. You get a flat-rate price before any work begins, and repairs are guaranteed for one year, parts and labor.
Rather pick a time yourself? Book a tune-up, free estimate or repair visit online, any time of day.
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What it costs
- Service call (diagnosis): $99 weekdays 7 a.m. to 5 p.m.; $179 nights, weekends and holidays
- Repairs: flat-rate, approved before work starts, guaranteed 1 year parts and labor
- Annual boiler service: ask for current pricing
- Replacement estimate: free, in writing
- New boiler: financing on approved credit, including 0% APR for 18 months on qualifying installs through Marine Credit Union with no down payment and 18 equal monthly payments; rebates on qualifying units
- Gas boiler replacement, national range: $4,000 to $10,000 installed (price guide)
How it works
What happens when you call A-1
1
You call or text, any hour
A person answers 414-595-5175, not a call center. We ask a few quick questions and give you a real arrival window, not a guess.
2
We find the actual problem
We test before we replace anything and show you the readings, so you can see what failed and why.
3
You approve a flat-rate price
You get the price before any work starts, with repair and replacement options in writing when both make sense. No hourly surprises.
4
We fix it, test it and clean up
Most repairs are finished on the first visit. We test the system, clean up after ourselves and explain what we did.
Specials, financing and rebates
Comfort you can afford, all year.
Everyday offers with no expiration date. Mention the one you want when you book; details are on the Specials page.
$89
Precision Tune-Up
Furnace or AC. A full safety and efficiency check before the season hits, with a written report of what we found. Book it online.
$500 off
A new furnace or AC install
Lennox and Rheem high-efficiency systems, installed to code and permitted when required, with our 10-year parts and labor warranty on installs registered with the manufacturer.
$1,000 off
Furnace + AC bundle
Replace both at once and save $1,000 instantly on a qualifying high-efficiency furnace and air conditioner package.
0% APR for 18 months
Through Marine Credit Union on qualifying installs, on approved credit; no down payment, 18 equal monthly payments. Wells Fargo and our in-house plan are also available.
Already have a replacement quote? Get a free second opinion.
We will give you our own written replacement estimate, free. If we think a repair makes more sense than a new system, we will tell you.
Never think about a tune-up again: join the A-1 Comfort Club.
A yearly maintenance visit for each system and priority on no-heat and no-cool days, plus 15% to 20% off repairs on the higher plans. From $150 a year for one system.
Why Milwaukee calls A-1
Big-company standards. Local-shop accountability.
Flat-rate pricing, quoted first
You approve the number before a tool comes off the truck. No hourly surprises, no upselling.
24/7, and no call center
After-hours calls ring Mike’s cell, not a call center. If he is on another call, text or leave a message and you hear back quickly.
Authorized Lennox and Rheem dealer
Factory-backed equipment and warranties, and we service every brand you already own: Carrier, Trane, Goodman, York, Bosch, Mitsubishi and more.
Repairs guaranteed 1 year, installs 10
Every repair is guaranteed for one year, parts and labor. New Lennox and Rheem installs registered with the manufacturer carry a 10-year parts and labor warranty, with limited lifetime heat exchanger coverage on select models.
State-registered, veteran-owned
Wisconsin Registered HVAC Contractor #1304500, BBB A+ accredited, NATE-certified technicians, and a crew of eight with 115+ years in the trade. One shop in South Milwaukee since 2014.
4.9 stars from 440+ neighbors
Every review is public, including the critical ones, and we reply to them. Judge us by the whole record.
Good to know
Frequently asked questions
My boiler is running but the radiators are cold. What is wrong?
The boiler is making heat but the heat is not moving: a dead circulator, a stuck zone valve, air trapped in the loop, or on a steam system, clogged vents or a flooded return. These are usually quick, inexpensive repairs. Our article Boiler running but radiators cold? walks through what to check first.
Do you work on both steam and hot-water systems?
Yes, both, including one-pipe and two-pipe steam. Steam is a specialty, and it is regular work for us all heating season.
Can you replace my old boiler with a high-efficiency one?
In most houses, yes. A condensing boiler needs the right venting and benefits from lower water temperatures, so we check your radiation and piping before recommending one. Sometimes a modern cast-iron boiler is the better value, and we will tell you when.
How often should a boiler be serviced?
Once a year, before heating season: combustion analysis, safety controls, relief valve, expansion tank, venting and a check of every zone. It keeps the system safe and catches small problems while they are cheap.
How much does a new boiler cost?
Nationally, a gas boiler replacement typically runs $4,000 to $10,000 installed, according to Fixr’s 2026 cost data. We could not find a reliable Milwaukee-only survey, and steam systems, venting and near-boiler piping can push a job past that range. You get a written price after we count your radiation. More in our Milwaukee HVAC price guide.
Are your repairs guaranteed?
Yes. Every repair is guaranteed for one year, parts and labor. If something we fixed fails within that year, call us and we make it right at no charge.
Reviews
What our customers say
Word-for-word excerpts from Google reviews, names shortened. Overall: 4.9 stars from 440+ reviews.
5 out of 5 stars
“We just bought a house in Cudahy and the previous owners kept inside/outside doors open long enough to let some critters in. Sure enough, a squirrel was living in the basement and chewed some wires on our boiler…”
Krista C. · Boiler repair, Cudahy · Google review
5 out of 5 stars
“I’m usually hesitant to call repair companies because I’d rather fix things myself, and it’s hard to know who to trust. Mike was honest, reliable…”
Gabriel H. · AC repair · Google review
5 out of 5 stars
“Had Mike come in on a very short notice call and was extremely professional and quick with his service. Clearly explained everything that was going on and all the options available to me.”
Angel R. · Short-notice service call · Google review
Read them all on Google
These are a few highlights. Google shows every review, including the critical ones, and we reply to them. Judge us by the whole record.
Ready when you are: