
Commercial HVAC Maintenance in Bay City, MI
HVAC Tune-Ups for Commercial Systems in Mid-Michigan
Keeping your commercial HVAC system running smoothly isn’t just about comfort; it’s about protecting your investment, reducing downtime, and staying ahead of expensive repairs. At Custom Engineering, we’ve been working with local businesses in Bay City, Saginaw County, and Midland since 1984 to keep systems running reliably year-round.
Whether you manage a small storefront or a larger commercial property, our tune-up and inspection services are built around what works best for real businesses right here in mid-Michigan.
Looking to schedule a service or talk through a maintenance plan? Call us today at (989) 474-2870 and we’re available 24/7.
Reliable Commercial HVAC Maintenance
Commercial HVAC systems face significant wear, especially with Michigan’s extreme weather fluctuations. Regular maintenance is crucial for keeping your system efficient and preventing costly breakdowns. At Custom Engineering, we offer seasonal tune-ups and inspections that identify and address small issues before they become major problems.
We work around your schedule and building layout to create a maintenance plan that minimizes disruption to daily operations. Plus, we provide ongoing maintenance reminders so you never miss a check-up.

Custom Comfort, Professional Care
What Makes Us Different?
At Custom Engineering, we will always put you first. That's why so many people in Linwood trust us time and again.
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Affordable Financing OptionsWe make HVAC services affordable with financing options offering 0% interest for 72 months.
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Available Nights & WeekendsNo matter when you need us, we're ready to help. Someone is always available to answer your call.
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Preventative Maintenance PlansKeep your system in perfect shape all year round with our programs.
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Locally Owned & OperatedAs a proud Michigan company, we deliver honest, dependable HVAC services backed by local expertise and care.
What’s Included in a Commercial HVAC Maintenance Visit?
System Check & Diagnostics
We perform a full system check to assess performance, testing key components and identifying any early signs of wear. If something’s not working as it should, we’ll explain the issue clearly.
Filter Replacement & Internal Cleaning
Air filters in commercial settings can clog quickly, reducing airflow and making your system work harder. We replace dirty filters and clean dust or debris inside the unit.


Trusted by homeowners and Businesses Since 1984
At Custom Engineering, your satisfaction is our priority! See for yourself what our customers have to say about working with us.
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I needed help, and Custom Engineering got to me fast and saved the day. Nick, the technician, was great. He was personable and intelligent and he got my repair done super fast. Thanks, Custom Engineering!- James T.
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Quick, efficient, and friendly service from both office staff and techs. Fair pricing. Grateful for their help on a freezing day when our furnace failed. Feared the worst. Highly recommend this company!- Tammie S.
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We went through custom engineering for replacing our furnace and air conditioner. They went above and beyond to do what is best for our home. The whole team was respectful and informative. They answered any questions we had!- Allison E.
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I always try to keep my business local, so I called Custom Engineering. They always answered my calls promptly, and the service was friendly with experienced technicians. They were prompt, courteous, and really put my fears to rest. Great job!- Debbie M.
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Chaz went above and beyond! He fixed my main house furnace and also advised me on my ceiling-mounted furnace in my back building. Thank you for your quick response. I will use you again!- Ann K.
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He got our furnace up and running again very quickly (on a Saturday!). Very personable and professional! We will definitely be using Custom Engineering Heating & Cooling again - thank you!- Krista W.
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Every employee I have had the pleasure of dealing with has been top-notch. Today's visit by Tyler for annual maintenance was great. He was punctual, friendly, and professional.- Michelle G.
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Had Customer Engineering come out to my restaurant to diagnose my furnace and walk-in freezer. Brandon and Skylar, the techs, were amazing. Extremely friendly and knowledgeable. I will be using them for all my HVAC needs moving forward.- Taylor A.
Why Seasonal Maintenance Matters in Mid-Michigan
In mid-Michigan, shifting weather can place significant stress on your HVAC system. Seasonal maintenance helps your system adjust to these changes and operate at its best. In the spring, we focus on getting your cooling system ready for the warmer months by checking refrigerant levels and cleaning key components. In the fall, we prepare your heating system by inspecting parts like the ignition system and heat exchanger, helping maintain reliable performance during the colder weather.
Contact us today at (989) 474-2870 or online to book your commercial HVAC maintenance visit. We’re here to help whenever you need us.