Troy particulars
Troy enforces load calculations on new construction. For projects starting January 12, 2026, the city says new and addition residential work needs a performance-based compliance report and the Manual J, Manual S and Manual D design submittals. For replacement-only furnace or AC jobs, its page says alterations to a mechanical system must conform to the requirements for a new mechanical system. For heat we use the Detroit Metro airport normals because that is the nearest station we read, about 6,067 heating degree days a year (base 65 F).
DTE Electric and Consumers Energy are the electric and gas utilities whose territory covers Troy, so a gas furnace replacement points to Consumers Energy's 2026 chart (installs January 1 to December 31, 2026, amounts can change without notice). Troy publishes no city rebate that we read. The Building Department, 500 W. Big Beaver Rd, 248-524-3344, takes mechanical and other trade permits through BS&A Online, and permits needing plan review go in as PDFs by email.
Inspection requests run through BS&A or 248-689-5744, with a 2 PM cutoff. The city's 2026-27 fee schedule lists a $75 minimum mechanical permit; our reading of that schedule is medium confidence, so confirm the fee. About 60.5 percent of homes predate 1980. Clawson and Royal Oak are near. Our furnace repair page covers common faults.
Furnace repair in Troy: what to know
Troy's heating load is the Detroit Metro airport figure, the closest station we read: about 6,067 heating degree days a year at base 65 F. Consumers Energy is the only natural-gas utility whose territory covers the city. At 60.5 percent of homes built before 1980, Troy's housing is newer than most of this group.
The Building Department at 500 W. Big Beaver Rd, 248-524-3344, takes mechanical permits through BS&A Online. The 2026-27 fee schedule lists a $75 minimum and $98 for a gas burner up to 75,000 BTU, but mapping a residential furnace to that row is our reading, so confirm with the department. Troy also says an alteration to a mechanical system must conform to the requirements for a new one.
Permits for furnace repair in Troy
LARA's rule says mechanical work needs a permit except for replacement of minor parts, so a repair that swaps a part generally does not, while replacing the furnace does (our reading of LARA's exemption list).
Furnace problems that cannot wait
- You smell gas: leave, then call 911 and your gas utility from outside.
- A carbon monoxide alarm is sounding: get into fresh air, call 911 and stay out until told it is safe (see the carbon monoxide guide).
- Several people have flu-like symptoms without a fever; SEMCO lists headache, fatigue, nausea and dizziness as carbon monoxide symptoms.
- No heat in freezing weather: see emergency HVAC repair.
- A furnace that heats but runs louder than it used to, with no gas smell and no alarm.
Three checks before you call
Try this first: have the contractor say whether the repair touches the venting or only the controls, since the city's wording on alterations depends on it.
- Set the thermostat to heat, above the room temperature, with fresh batteries if it takes them.
- Check the filter and change or clean it; ENERGY STAR says to do this monthly.
- If it still will not start, note any light pattern or code and stop. Do not remove panels or relight anything after a gas smell.
What furnace repair costs
The estimate below is the Michigan-wide one, adjusted for Michigan wages and not for Troy in particular. The same table is on the furnace repair page. How we estimate costs. Prices as of Oct 19, 2026.
| Item | Figure | What it is |
|---|---|---|
| Estimated range, not a quote | $105 to $550 per repair | Built from one national published range, adjusted by the Michigan HVAC technician wage ratio (1.00). |
| Technician wage, Michigan mean | $31.01 an hour | Technician pay (BLS, May 2025), not a price. |
| Furnace replacement permit, Grand Rapids | $21 plus a $52 application | Effective July 1, 2026; $73 by our addition. |
| Gas or oil furnace permit, Sterling Heights | $57 up to 75,000 BTU, plus $55 application | 2026-2027 form. |
| Heating system permit, Dearborn | $50 up to 75,000 BTU | Plus $100 administrative fee. |
| Residential furnace permit, Westland | $83 up to 75,000 BTU | Plus $100 administration fee. |
| Residential furnace permit, Warren | $80 | Form dated 4/25/2023; confirm with the city. |
| Residential heating system permit, LARA state | $50 plus a $75 application | Only where the state enforces the code. |
How we estimate costs: the figures here are estimates, not quotes, built from BLS wages, published city permit fees and federal energy-cost evidence. We are collecting the prices Michigan heating and cooling companies publish; we have not yet collected quotes from them, and we will say how many and from when once we do. Estimated range. Built from national published ranges (1 source), adjusted by Michigan's HVAC technician wage ratio to the US (1.00, BLS May 2025), plus the local permit fee where the city publishes one. Not a quote. We have too few Michigan company prices yet to show a range. Full method.
Questions about furnace repair
What is the average lifespan of a furnace?
The federal and ENERGY STAR pages we could read give none. ENERGY STAR does say equipment more than 10 years old should be evaluated by a professional HVAC contractor, which is a reason to ask for an inspection and gives no expiry date.
How much does furnace repair or a service call cost in Michigan?
The first row of the cost table is a statewide estimate, a model and not a quote. The rows below show technician wages, a Michigan mean of $31.01 an hour (BLS, May 2025), which is pay, not a charge. Ask what the visit fee covers and get the repair price in writing before work starts.
What is the $5,000 rule for furnaces?
Contractors and homeowners pass it around, but no federal or state page we read states it. The repair-or-replace tool shows it only as a labeled rule of thumb; ENERGY STAR's 10-year evaluation advice is the sourced alternative.