Graystone Comfort
Heating and Cooling Services in Mundelein, IL
From the older streets near the village center to the subdivisions out toward Diamond Lake, Mundelein covers a lot of ground and a lot of housing types. We work across all of it — and we know which questions to ask depending on where you are.

Graystone Comfort
Heating and Cooling Services in Mundelein, IL
From the older streets near the village center to the subdivisions out toward Diamond Lake, Mundelein covers a lot of ground and a lot of housing types. We work across all of it — and we know which questions to ask depending on where you are.

Mundelein isn't one kind of place. There are homes near the village center that have been there since well before the subdivisions went in, lake-adjacent properties that started life as seasonal cottages, newer developments on the edges, and unincorporated pockets where the rules are different from the village's.
That variety matters more than it sounds. A water heater replacement on a private well is a different job than one on municipal water. A permit for an unincorporated address goes through a different office. We ask first rather than assuming.
Our Services
HVAC Installation, Maintenance & Repair in Mundelein
Heating & Furnace
Furnaces, boilers, and heating repairs across Mundelein. In older homes and converted properties, we check whether the system was ever properly sized for how the house is used now.
Air Conditioning
Repairs, replacements, and spring tune-ups throughout the village and the surrounding unincorporated areas.
Water Heaters
Gas, electric, and tankless. Water quality has a real effect on how long a water heater lasts around here, and it changes what we'd recommend — especially if you're considering tankless.
Indoor Air Quality
Humidity control, filtration, and duct solutions. Lake-adjacent and older homes often have humidity patterns that newer construction doesn't.
Commercial HVAC
Mundelein has a substantial light industrial and commercial base. We service and install commercial systems for shops, offices, and industrial buildings.
Emergency Service
Breakdowns don't wait for business hours. Call us any time.
Learn more ->
Call us at 224-933-4305 today!
Heating and Cooling Services
What we see in Mundelein homes
Hard water and what it does to a water heater
Groundwater in this part of Lake County carries a significant mineral load, and homes on private wells feel it most. Scale builds on the tank bottom and on heating elements, which shortens the life of the unit, reduces efficiency, and produces the rumbling or popping sound a lot of homeowners describe. If you're on a well, annual flushing matters more than the manual makes it sound.
Cottages that became year-round homes
Around Diamond Lake and the other lake-adjacent areas, a number of properties started as seasonal places and were converted over the decades. The heating systems in those homes often grew by accretion — a furnace here, baseboard there, an addition tied into whatever was closest. They frequently work, but they're rarely balanced, and the underlying design was never meant for January occupancy. If your lake-area home has rooms that have never been comfortable in winter, that's usually why, and it's diagnosable.
Unincorporated addresses and a different permit office
Not everything with a Mundelein mailing address is inside the village limits. If your property is in unincorporated Lake County, permitting and inspection go through the county rather than the Village of Mundelein, and the requirements aren't identical. It catches people out, including contractors. We check which jurisdiction applies before the work is scheduled, not after.
Light industrial and commercial space
Mundelein has more manufacturing and industrial building stock than most of its neighbors, and those buildings run equipment on a different scale with different service needs. We handle commercial alongside residential.

Call us at 224-933-4305 today!

Why Choose Graystone Comfort?
A Different Kind of HVAC Company
We're a family-run, woman-owned business, and one of the very few like it in Lake County. Every job gets the same attention, whether it's a furnace tune-up in Mundelein or a full system replacement in Lake Forest.
Our founder spent twenty years in the trades before starting this company — working her way from technician to operations manager at one of the Chicago area's largest HVAC firms. She knows what good work looks like, and what it takes to earn a neighbor's trust and keep it.
100% Satisfaction Guarantee
Fully Bonded and Insured
Decades of HVAC Experience
Graystone Comfort Reviews
Hear It From Our Customers

"I wish all contractors were this good!"
"Graystone is the most professional HVAC company I've ever worked with. They installed my Ecobee and replaced my humidifier. I couldn't recommend them more. I wish all contractors were this good!"
Greg A.

"I would recommend them to anyone."
"I have used Graystone Comfort for AC and heater maintenance. They are very professional and don’t mind answering your question, even a text away. I would recommend them to anyone."
Ariana V.

"They will be the only people we call from now on."
"We had air conditioner issues over the holiday weekend. Nichole was amazing came over and trouble shot what we needed and was able to fix it and give us a reasonable quote for a new air conditioner and furnace. They will be the only people we call from now on."
Lisa S.
Flexible Financing
Comfort now, payments over time
Get the system your home needs now, and pay over time. Prequalifying takes just a few minutes.
Our Service Area
Nearby HVAC Service Areas
Lake County is home base, and we take calls throughout Northern Illinois — Libertyville, Vernon Hills, Grayslake, Lincolnshire, and beyond.
If you're not sure whether we cover your area, just call. The answer is probably yes.

FAQ
Common Questions About Heating and Cooling Services
Does hard water affect my water heater?
Yes, noticeably. Mineral scale builds on the tank bottom and heating elements, which shortens the unit's life, costs efficiency, and causes the rumbling sound many homeowners notice. Annual flushing helps, and it matters more on a private well than on municipal water.
Is a tankless water heater a good idea if I'm on a well?
It can be, but it needs planning. Tankless units are less tolerant of hard water than tanks are, so treatment and periodic descaling are part of the deal. We'll tell you honestly whether it makes sense for your situation.
My address says Mundelein but I'm not in the village. Does that change anything?
For permitting, yes. Unincorporated Lake County addresses go through the county rather than the Village of Mundelein, and the requirements differ. We confirm which applies before scheduling work.
My lake-area home has rooms that are never warm in winter. Why?
Often because the house was originally seasonal and the heating system grew piecemeal as it was converted and added onto. It's usually a design and balance problem rather than a failing furnace, and it's diagnosable.
Do you offer emergency HVAC service in Mundelein?
24 hours a day, seven days a week. Call 224-933-4305.
Do I need a permit to replace my furnace in Mundelein?
Yes. Inside the village, permits go through the Village of Mundelein; for unincorporated addresses, through Lake County. We handle the permit and inspection either way.
How often should I service my air conditioner?
Once a year, in the spring. More on why Northern Illinois is hard on cooling equipment: How Often Should You Service Your Air Conditioner in Northern Illinois?
