Official Heating & Cooling

Call Directions Website

Official Heating & Cooling McNally's Heating & Cooling (formerly Harmonic HVAC Crystal Lake & Official HVAC) proudly provides trusted HVAC services in Crystal Lake and nearby areas.

Homeowners rely on our team for reliable heating and cooling repair, maintenance, and installation. 36 years experience with sales, service and installations. Hands on ownership withpersonal involvement in every installation of new equipment. Always available to answer any HVAC related questions from our customers.

09/23/2026

🏆 Best of McHenry County 🏆

One year after planting deeper roots in McHenry County with our Crystal Lake location, we’re proud to be recognized as Best Business-to-Business Service! 💚

Being locally owned means more than doing business here, it means being part of the community. Our goal has always been to treat your home like family, support local events and organizations, and show up when our neighbors need us most.

We’re just getting started, McHenry County. Thank you for welcoming McNally’s and for your continued support!

Thank you, McHenry County! 💚🏡

🔥❄️ Call to take advantage of these offers and get on our schedule! 📲815-344-0400
06/10/2026

🔥❄️ Call to take advantage of these offers and get on our schedule!
📲815-344-0400

☀️ June is here, and that means your A/C system is working hard to keep your family comfortable! 🏡

Now is the perfect time to take advantage of our seasonal specials:

✅ $99 A/C Tune-Up – Make sure your system is ready for the summer heat.
✅ $35 Off Service Repairs – Save when unexpected issues pop up.
✅ 25% Off Duct Cleaning – Improve your indoor air quality by removing dust, debris, and allergens from your ductwork.

Don’t wait until the hottest days of summer 👉schedule your appointment today!

📍 St. Charles: 630-363-9067
📍 Crystal Lake: 815-344-0400

🌐 www.mcnallyhvac.com

McNally’s Heating & Cooling is here to help keep your home comfortable all season long!

⛳️
06/10/2026

⛳️

Join the team! 🍀🏆
05/09/2026

Join the team! 🍀🏆

Join McNally's Growing Team - HVAC Careers Service Technicians Needed. Find our More and Apply Today. Keep our Communities Warm Year Round.

05/09/2026

🌸 Spring is heating up and temperatures are on the rise! 🌡️

Is your A/C ready for the warm season ahead? Don’t get caught in the heat!☀️ 𝗚𝗲𝘁 𝗮 𝗽𝗿𝗼𝗳𝗲𝘀𝘀𝗶𝗼𝗻𝗮𝗹 𝗔/𝗖 𝗧𝘂𝗻𝗲-𝗨𝗽 𝗳𝗼𝗿 𝗷𝘂𝘀𝘁 $𝟵𝟵!

✅ Improve efficiency
✅ Prevent costly breakdowns
✅ Stay cool all summer long

Beat the rush and schedule your tune-up today!

📞 Call us at 630-363-9067 or 815-344-0400
💻 Book online today www.mcnallyhvac.com/schedule

🍀🍀🍀
05/09/2026

🍀🍀🍀

🔧 Technician Tuesday Spotlight: Rigo 🔧

Fast, reliable, and 5-star service — that’s what we love to see! 🙌

Anthony shared this great feedback:
“Rigo was amazing!! Came right at 8:00 and had everything working within the hour! Great customer service and fast appointments! Highly recommend.”

👏 Way to go, Rigo! Your prompt service and dedication to getting the job done right make all the difference for our customers.

📞 815.344.0400
🌐 www.mcnallyhvac.com

Mother’s Day Weekend is here! 💗
05/09/2026

Mother’s Day Weekend is here! 💗

This Mother’s Day, go beyond flowers. Give Mom the comfort of clean, healthy air. 💨💖

From May 1 to May 15, take 25% OFF APCO UV Air Purification Systems, a gift that keeps your home feeling fresh, safe, and comfortable every day. 🎁🏡

As your trusted local team, we’re here to make your home the best it can be for the people who matter most. 💐✨

Breathe easier knowing we’ve got the air covered, so you can enjoy the celebration.

📞 Call (630) 363-9067 | (815) 344-0400
🌐 Schedule online: www.mcnallyhvac.com

💝 Make clean air part of Mom’s special day.

04/21/2026
04/21/2026
04/14/2026

Address

150 S Virginia Road, Suite #4
Crystal Lake, IL
60014

Opening Hours

Monday 8am - 5pm
Tuesday 8am - 5pm
Wednesday 8am - 5pm
Thursday 8am - 5pm
Friday 8am - 5pm

Telephone

+18003504822

Alerts

Be the first to know and let us send you an email when Official Heating & Cooling posts news and promotions. Your email address will not be used for any other purpose, and you can unsubscribe at any time.

Shortcuts

Share