Your trusted home service experts

Your Trusted HVAC & Electrical experts in St. Louis

Reliable home service since 1972. We bring integrity, discipline, and decades of expertise to every job — keeping you comfortable and safe, year-round.

Proudly Black and Veteran Owned — a St. Louis family serving our community with integrity since 1972.

Repair

Ensuring your heating and cooling systems get back to optimal performance.

Installation

Upgrade your home or business with energy-efficient HVAC systems.

Maintenance

Prevent breakdowns and improve energy efficiency with our regular maintenance services.

Electrical Maintenance

Ensuring your electrical systems operate safely and efficiently.

Electrical Installation

Our electrical services provide safe and dependable solutions for all your power needs.

Electrical Repair

We troubleshoot and fix electrical issues efficiently.

 TRUSTED SERVICE, LASTING IMPACT

WHY Diagnostic

Heating & Cooling

Trusted since 1972 - three generations leading with integrity for your HVAC and electrical needs. Here's what our customers have to say:

They were great! Father and son came to work on my electric furnace and they got it fixed! I will have them work on my ac this summer

Sara Hull

Five gold stars in a row on a white background

Tim was great! He updated wiring and installed a new stove for us and we couldn't be happier!

Kevin Straubs

Five gold stars in a row on a white background
Technician kneels on rooftop inspecting HVAC unit with gauges and tools connected to pipes

Your peace of mind comes first

Why St. Louis Chooses Diagnostic Heating & Cooling

With decades of hands-on experience across HVAC and electrical, we're committed to honest work and doing right by every customer.

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Experienced Team

For over 70 years, we’ve been in the HVAC Industry.

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HVAC & Electrical Experts

One licensed team for your heating, cooling, and electrical. We diagnose the real problem and fix what actually needs fixing.

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Licensed, Insured & Bonded

We meet the highest local and regional standards, and use only certified products.

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Competitive Pricing

Fair, upfront pricing you can count on. You'll know the cost before we start.

Committed to Comfort and Excellence Since 1972

Our family-run team combines decades of experience with modern tools to deliver honest HVAC and electrical solutions for homes and businesses. We're proud to be a trusted name throughout St. Louis and the surrounding area, treating every property like our own.

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401 Pine St, St. Louis, MO 63102, US

Proudly Serving St. Louis and Beyond

Providing expert HVAC and electrical services to St. Louis, MO, and surrounding areas. Wherever you are, we’re ready to help.

Financing Available!

Flexible payment options to fit your budget. Call us to set up an estimate and ask about financing- a simple process, with options to fit your project.