Quick Answer
A furnace inspection in Flint, MI is available as a standalone service from an HVAC contractor, or it's included as part of a Mike's Complete Home Inspection visit at no additional charge with thermal imaging on every system. The visit identifies cracked heat exchangers, carbon monoxide leaks, blower motor problems, and end-of-life systems while there's still time to repair or replace.
Why a Furnace Inspection Matters in Mid-Michigan
The first cold snap in Genesee, Lapeer, Shiawassee, Saginaw, and Oakland County is usually mid to late October. By Thanksgiving, the furnace is running every night. By January, it's running 18 hours a day. If something is wrong with the system, October is the only month where you can fix it without paying emergency rates or sleeping under five blankets.
The risks of running a compromised furnace are real. Cracked heat exchangers leak combustion gases into the supply air. Failing draft inducers vent flue gases incorrectly. Disconnected vents pump CO into living space. None of these are theoretical. We see them every winter on inspections of homes across Mid-Michigan.
A pre-season inspection identifies all of those issues before they matter.
What Goes Wrong With Older Flint Furnaces
The Mid-Michigan housing stock skews older than national average. Lots of homes in Flint, Burton, Mt. Morris, and Davison still run furnaces that are 20 to 30 years old. The most common problems we find:
- Cracked heat exchangers. Standard-efficiency furnaces from the 1990s and early 2000s commonly develop heat exchanger cracks at end of life. Cracks let combustion gases (including CO) bypass the flue and enter the home's supply air.
- Failed draft inducers. The small motor that pulls combustion gases through the heat exchanger. When it fails, the system either won't fire or fires unsafely.
- Disconnected or sloped flue pipes. Common in basements with utility-room renovations. Slope back toward the furnace causes condensate problems and CO risk.
- Dirty or blocked burners. Pets, dust, basement humidity, and time. Clogged burners burn inefficiently and produce more CO.
- Worn blower motors and capacitors. Often the first failure on a working system. We hear them before they fail.
- Improper combustion air. Newer tight homes don't have enough air for safe combustion. We measure and verify.
- Aging gas valves and pilot assemblies. Standing-pilot systems need attention every season. Most have been replaced by electronic ignition; the ones that haven't are due.
How a Furnace Inspection Actually Works
A thorough furnace inspection has three layers: visual, operational, and instrumented.
Visual inspection:
- Heat exchanger surface, where accessible
- Flue pipe condition and slope
- Combustion air supply
- Gas line and shut-off valve
- Electrical connections and wire condition
- Filter housing and filter condition
- Cabinet, blower compartment, and blower wheel
- Drain pan and condensate handling on high-efficiency systems
- Combustion air dampers and combustion ventilation
Operational test:
- System start-up sequence (call for heat, ignition, blower delay, run, shutdown)
- Temperature rise across the heat exchanger
- Cycling behavior on thermostat call
- Limit switch response
- Carbon monoxide reading at the supply air at multiple points during operation
Instrumented test (thermal imaging on every Mike's inspection):
- Thermal scan of the heat exchanger to identify uneven heating that suggests cracks
- Thermal scan of supply ductwork to identify leaks and disconnections
- Thermal scan of return air to identify infiltration
- Thermal scan of the cabinet to identify insulation gaps and air bypass
- CO measurement at the supply registers in living areas
A standard HVAC service tune-up usually skips the thermal imaging and the supply-register CO measurement. Both matter, and both have caught life-safety issues that visual inspection alone would have missed.
Carbon Monoxide and Older Homes
Most Genesee County CO incidents we hear about trace back to one of three causes: a cracked heat exchanger, a disconnected flue, or a backdrafting water heater that shares the chimney with the furnace. All three are visible during inspection. None of them announce themselves to the homeowner before they cause harm.
If you live in a home with a furnace older than 15 years, CO detectors near every sleeping area are non-negotiable. If you live in a home with a furnace older than 20 years, an annual professional inspection is non-negotiable. If you live in a home where you can hear the furnace running and don't know how old it is, October is the time to find out.
Repair vs. Replace Decision
For an older furnace, the question by mid-life is repair or replace. Some rules of thumb we use in Mid-Michigan:
- Under 10 years old: Repair almost always wins. Components are still available, efficiency is still reasonable.
- 10 to 15 years old: Repair if the issue is small (igniter, capacitor, blower motor). Replace if the issue is structural (heat exchanger, control board on a low-efficiency unit).
- 15 to 20 years old: Replace once a major component fails. The combination of efficiency improvements and remaining service life makes replacement the better long-term value.
- Over 20 years old: Replace at the first significant failure. The remaining life is short and energy costs are high.
A modern 96 percent efficient furnace replacing an 80 percent efficient unit cuts heating bills by about 17 to 20 percent in our climate. Over a 15-year life, that often pays for the replacement.
We don't sell or install furnaces. Our role is to give you the data so you can make the call without pressure.
Furnace Inspection on a Home Purchase
If you're buying a home in the Flint area, the furnace is one of the first things we evaluate during the inspection. We document age, manufacturer, model, capacity, last service date if available, and current condition. Heat exchangers get a thermal scan. CO levels get measured at the registers. Filter condition tells us how well the system has been maintained. The report tells you what to expect financially: years of service remaining, repair items to address, and replacement timing.
For most Mid-Michigan buyers, this evaluation is the difference between a clear go-decision and a costly surprise in February.
Related Reading
- Winter-Ready, Essential Home Maintenance Checklist
- Frozen Pipe Prevention for Michigan Homes
- What Fails a Home Inspection in Michigan?
- How Much Does a Home Inspection Cost in Michigan?
- Moisture, Mold, and Your Home, A Professional's Guide
FAQ
Should I get an HVAC tune-up or a home inspector furnace inspection? Both serve different purposes. An HVAC technician will clean and service the system. A home inspector evaluates condition and remaining life. If you're maintaining a home, get the tune-up. If you're buying or evaluating, get the inspection. Many homes benefit from both.
Can a furnace inspection find every heat exchanger crack? No inspection method catches 100 percent. Visual inspection plus thermal imaging plus CO measurement at the supply registers catches the vast majority. The only definitive test is disassembly, which isn't done routinely. Combined methods are the practical standard.
What if I have a high-efficiency furnace? High-efficiency (90 percent and up) furnaces have different failure modes: condensate drain problems, secondary heat exchanger corrosion, vent material issues with PVC. We inspect the same way, with attention to those specific systems.
Do you inspect boilers and heat pumps? Yes. Hydronic boilers, heat pumps (air source and ground source), and combination systems all get inspected. Older Flint homes with cast-iron boilers, gravity systems, and converted-coal furnaces all get the same methodical evaluation.
How long does a furnace inspection take? About 30 to 45 minutes as part of a full home inspection, or 45 to 60 minutes as a standalone visit if we're not inspecting the rest of the home.
Schedule Your Furnace Inspection in Flint, MI
We inspect heating systems across Flint, Grand Blanc, Burton, Davison, Fenton, Lapeer, Owosso, and Saginaw before winter every year. Schedule by calling or texting (810) 423-2360, or learn more about our home inspection in Flint, MI and infrared inspection services.