Heating & Cooling Services in Darien, WI

Heating & Air Conditioning for Walworth County Homes & Businesses

Since 1978, H.J. Faust, Inc. has kept residential and commercial customers in Darien, Wisconsin, comfortable through every season. With more than 20,000 clients served across southeastern Wisconsin, we bring decades of local experience to every call. Our services cover the full range of HVAC work: furnace and air conditioning repair, system installation and replacement, new construction, design-build projects, system upgrades, and sheet metal fabrication.

We’re a Lennox Premier Dealer and install Lennox systems, and our technicians service all major brands, including Carrier, Daikin, Goodman, Honeywell, Trane, and Bryant. Every technician is fully licensed, insured, factory-trained, and NATE-certified, meaning they meet nationally recognized standards in heating, cooling, ventilation, and refrigeration on every call.

Ready to schedule service or get a free estimate? Call us at (262) 418-0700, and we can find a time that works for you.

How Our Darien HVAC Technicians Are Trained

The quality of an HVAC installation or repair comes down to the person doing the work. We train our mechanics through the state-approved Associated Builders and Contractors (ABC) Apprentice Program, a five-year curriculum that combines classroom instruction with hands-on field work under direct Senior Mechanic supervision. It’s a structured, rigorous path that produces technicians who understand not just how to swap a part, but how a system is supposed to perform.

Training doesn’t stop at certification. Every field and office employee completes a minimum of four training sessions per year to stay current on new equipment, technologies, and processes. When our technicians arrive at your Walworth County home or business, they know what they’re looking at.

Honest Repair-or-Replace Guidance

Every service call starts with a thorough inspection. We don’t recommend a solution until we understand the problem, and we don’t suggest more than your system actually requires. If a repair makes sense, we’ll say so. If your system has reached the point where continued repairs may cost more than a replacement would, we can walk you through that math clearly and let you decide.

Signs your system may need attention:

• No warm air from the furnace or no cold air from the air conditioning
• Rattling or pinging sounds during operation
• Discolored pilot light
• Frequent on-and-off cycling
• A sudden, unexplained rise in energy bills

Annual Maintenance Agreement for Darien Homeowners

HVAC systems tend to fail on the hottest and coldest days of the year, exactly when everyone else is calling for service too. Our Annual Maintenance Agreement is designed to catch problems before they become emergencies. The program includes both a furnace check-up and an air conditioning check-up, with a 30-point inspection at each visit. We recommend scheduling the AC check-up in spring and the furnace check-up in fall.

Agreement members receive priority scheduling, no overtime charges for after-hours calls, and a 10% discount on all parts and labor when repairs are needed. It’s a cost-effective way to help protect your equipment and extend its useful life.

Schedule HVAC Service in Darien, Wisconsin

We’ve earned an Excellent rating based on hundreds of Google reviews. Customers consistently point to our promptness, clear communication, and thorough work as reasons they call us back. We’re also BBB accredited, which means we’re accountable to a recognized standard of business conduct, not just our own word.

When you need help at 2 a.m. in January, our 24/7 emergency service means you’re not waiting until morning. We’re available around the clock for heating and cooling calls because comfort emergencies don’t follow business hours. Free estimates are available, and financing with approved credit may be available for new equipment installations. Whether you need a repair, a new system, or want to ask about our Annual Maintenance Agreement, we’re easy to reach.

Call (262) 418-0700 or contact us through our website to schedule at a time that works for you.