Short answerAt typical market pricing in Washtenaw and western Wayne County, common furnace repairs like flame sensors, ignitors, pressure switches and thermostat faults land in the low to mid hundreds including the service call. Inducer motors, blower motors and control boards run from the mid hundreds to around a thousand. Heat exchanger replacement reaches the low to mid thousands and usually means a new furnace is the better buy.
What a no-heat call usually turns out to be
Most furnace failures in Southeast Michigan are not dramatic. The furnace in a Ypsilanti Township ranch tries to light three times and locks out; the one in a Saline colonial runs for 90 seconds and shuts down; the one in an Inkster bungalow does nothing at all. Behind those symptoms are a small number of parts that fail over and over, and the price of fixing them is fairly predictable once you know which one it is. What follows is typical market pricing for the area, grouped by the size of the job. It is not our price list; our furnace repair work is quoted flat-rate after diagnosis, before any part is touched.
Small repairs: low to mid hundreds
The parts that make up most winter calls, usually fixed in one visit with stock from the truck.
- Flame sensor cleaning or replacement. A rod coated with oxide produces a weak signal and the furnace shuts the gas off a few seconds after lighting. Cleaning is part of a tune-up; replacement is a small part.
- Hot surface ignitor. The silicon nitride or silicon carbide element that glows to light the burners. Brittle and finite-life; one of the most common parts we replace in December and January.
- Pressure switch or its hose. The switch that proves the inducer is pulling draft. Hoses crack, ports clog with condensate.
- Thermostat issues. Dead batteries, a failed thermostat, a C-wire problem on a smart thermostat the homeowner installed. The quick checks are in thermostat not working.
- Limit switch or rollout switch. Safety switches that trip from overheating or a flame rollout. The part is cheap; the reason it tripped, usually airflow, needs to be addressed.
- Condensate trap or drain clog on a 90%+ furnace. The water backs up, the pressure switch opens and the furnace stops. The symptom is in water around the furnace.
- Door switch, fuse, loose wire. The furnace is fine; something simple interrupted it.
A fair number of calls in this group end with no part at all. The furnace switch got bumped off by a laundry basket, the condensate pump float stuck, a return grille was covered by a rug, or the filter had collapsed into the blower. In those cases you pay the dispatch fee and get an explanation of what happened and how to keep it from happening again, which is the right outcome even if it feels anticlimactic.
Mid-size repairs: mid hundreds to around a thousand
- Inducer (draft) motor. The small motor that pulls combustion gases through the exchanger. Whines for a season, then seizes. Common on 2000-to-2012 furnaces in Canton and Pittsfield subdivisions.
- Blower motor. A PSC motor is the lower end. An ECM or variable-speed blower on a newer furnace is the upper end and can go beyond it, especially on a model where the motor and control module are sold together.
- Control board. The circuit board that sequences the furnace. Often fails after a power surge or from a loose neutral. Boards for discontinued models can be hard to source.
- Gas valve. Less common, but when it fails, it is a safety part and not a cleaning job.
- Condensate pump replacement on a 90%+ furnace that drains uphill to a sink.
- Blower wheel cleaning when it is caked badly enough to unbalance the motor.
Large repairs: low to mid thousands
- Heat exchanger replacement. The part is often covered by a long manufacturer warranty, but the labor to split the furnace apart is substantial, and the furnace that needs one is usually 15 or more years old. In most cases the money is better spent on a new furnace, and we say so.
- Secondary heat exchanger on a 90%+ furnace, which corrodes from condensate. Same calculus.
- Multiple simultaneous failures on an older unit, like a board plus an inducer plus an ignitor, where the total crosses into replacement territory.
The decision framework for this group is repair or replace your furnace. The short version: if the furnace is past 15 years and the repair is over a third of a new one, replacement usually wins.
What drives the quote
Furnace age and brand. Parts for a 2008 Carrier or Lennox are stocked; parts for a 1996 discontinued model may take days and cost more. We repair every brand, but we cannot invent a board that no longer exists.
80% versus 90%+. Condensing furnaces have more parts (two exchangers, a condensate system, PVC venting), and the parts are a bit pricier.
Warranty. Register your furnace. A registered 2018 furnace likely still has parts coverage on the inducer, board, and blower; you pay labor only. We check the serial number before quoting anything.
Access. A furnace in an open basement in a Wayne County ranch is faster to work on than one in a closet in a 1970s Belleville condo or a crawlspace under a 1950s Garden City ranch.
What else is wrong. A pressure switch that failed because the inducer is weak, or an ignitor that cracked because the furnace has been short cycling on a dirty filter, is a repair that comes back if only the symptom is replaced. A good diagnosis names the cause as well as the part, and the quote may include two items rather than one. That is not upselling when the second item is why the first one failed; it is upselling when it is a surge protector.
When you call. Many shops in the area bill overtime after 5 p.m. and on weekends and holidays. We do not. A New Year's Eve ignitor costs the same as a Tuesday afternoon ignitor.
How Temprasure handles the quote
The dispatch fee covers the trip and the diagnosis. Once we know what failed, you get a flat-rate price for the repair, and that fee is credited toward it if you say yes. If the furnace is old enough that the repair is a bad investment, we say that out loud, give a free estimate on replacement, and leave you to decide; more than one customer has told us we encouraged them to get a second opinion before replacing, and we are fine with that. For the replacement side of the math, see new furnace cost in Michigan.
One safety note that overrides all of this
If the diagnosis is a cracked heat exchanger, the furnace gets shut off, no matter what the repair costs. Carbon monoxide does not negotiate. If you ever smell gas, leave the house and call DTE at 800-947-5000 and 911 from outside; if a CO alarm sounds, get everyone out and call 911. The repair conversation can wait until everyone is safe.