Furnace Repair in Port Huron, MI
Furnaces here run from October through May. If yours quits, tell us what it's doing and a licensed contractor who covers St. Clair County will get in touch.
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Eight months of heat puts real wear on your furnace
Port Huron needs a working furnace from October through May. That's eight months of the year your system has to fire up on demand, and on nights that average 20°F, it's cycling on and off for hours to keep the house warm. Every one of those cycles puts a load on the igniter and the burner, and over a winter that adds up fast.
St. Clair County has seen 13 winter storms and 82 damaging wind events over the past ten years, and across Michigan more than a third of households lost power for at least a day in 2024. Most gas furnaces here, and 74.4% of homes use gas, need electricity to run the blower and controls, so a power outage in the middle of a cold snap can leave you with no heat even though the furnace itself is fine. When the power comes back, most furnaces restart on their own. If yours doesn't, or if it's been struggling to keep up on the coldest nights, that's usually a sign something inside it is already worn down.
- 8 months
- October through May, your furnace is on duty
- 20°F
- the average winter night it heats against
- 74%
- of homes here heat with gas, so most furnaces here burn gas
- 13 winter storms
- in ten years, the nights a failure hurts most
NOAA nClimDiv, 1991–2020 normals
A new furnace would cut about $140 a year off heating for a typical St. Clair County home.
Estimates for a typical St. Clair County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, Michigan fuel prices and NOAA climate normals. Your home will differ.
Repair makes sense when one part has failed and the heat exchanger is sound.
Replacement makes sense when the heat exchanger is cracked or the furnace keeps needing parts.
Michigan requires HVAC contractors to hold a state license.
The Board of Mechanical Rules tests contractors before granting this license, and the license is kept on record with the state. It covers the contractor as a whole, not the specific job, so the same license that qualifies someone to repair a furnace also covers other mechanical work they take on.
For a furnace repair, that license is what stands behind the person working on your gas line and burner assembly. A bad connection at the gas valve is the dangerous part of this job, and the state's testing is what gives you a way to know the contractor has been checked before touching it. In St. Clair County, 74.4% of homes heat with gas, so this kind of repair is a common call here.
Sources: Michigan Legislature · Michigan Department of Licensing and Regulatory Affairs
- Why won't my furnace turn on?
- Start with the thermostat. Make sure it's set to heat and set a few degrees above room temperature, and check that the display hasn't gone dark from dead batteries. If the thermostat looks fine, check your breaker panel, since a tripped breaker will cut power to the whole system. Furnaces also have a switch that looks like a light switch near the unit itself, often on or near the housing, and it needs to be on. If all of that checks out and the furnace still won't start, a contractor licensed through Michigan's Board of Mechanical Rules can find out whether the problem is the igniter, a safety switch, or something else.
- Why is my furnace blowing cold air?
- Most often this means the blower is running but the burners haven't lit, so air is moving through the ducts without being heated. A dirty flame sensor is a common cause, since it shuts off the gas as a safety measure even when the igniter is working fine. It can also mean the pilot light or igniter has failed outright. Check your filter too, since one that's badly clogged can sometimes trick the system into shutting burners off while the blower keeps running. If changing the filter doesn't help, this is a job for a licensed contractor, especially with 20°F nights common here from December through February and little room for the furnace to be out of commission.
- Why won't my furnace pilot light stay lit?
- This usually points to the thermocouple, the small sensor that tells the gas valve the pilot is actually burning. When it wears out or sits out of position, it reads the flame as out even when it's lit, and the valve shuts the gas off. A draft blowing across the pilot can cause the same problem, so check whether anything nearby is pushing air toward it. Dirt or soot on the pilot assembly can also block the flame from reaching the sensor properly. If relighting it doesn't hold, the thermocouple likely needs replacing, and that's a straightforward fix for a licensed HVAC contractor.