Furnace Repair in Duluth, MN
Furnaces here run from September through June. If yours quits, tell us what it's doing and a licensed contractor who covers St. Louis County will get in touch.
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Ten months of heat a year wears a furnace down
Your furnace runs from September through June here. That is ten months of the year the burner is lighting, and on nights that average 1°F, it is running most of those hours to keep up. All that cycling wears on the igniter and the parts that sense the flame. When one of them finally gives out, the furnace either won't light at all or shuts itself off partway through a cycle.
St. Louis County has seen 179 winter storms and 284 damaging wind events over the past ten years, and storms here take down power. Across Minnesota, 13% of households lost power for at least 24 hours in 2024. A furnace with no power will not run no matter what shape it is in, and when the power comes back, some won't restart on their own.
- 10 months
- September through June, your furnace is on duty
- 1°F
- the average winter night it heats against
- 51%
- of homes here heat with gas, so most furnaces here burn gas
- 179 winter storms
- in ten years, the nights a failure hurts most
NOAA nClimDiv, 1991–2020 normals
A new furnace would cut about $150 a year off heating for a typical St. Louis County home.
Estimates for a typical St. Louis County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, Minnesota 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.
Minnesota has no state license for HVAC contractors.
Minnesota doesn't license or register HVAC contractors for this kind of work. There's no state test behind the name and no state file on the business. Whatever trust you place in the person doing the repair has to rest on something other than a state credential, because Minnesota doesn't issue one.
A furnace repair still means working with a gas line, and a bad connection there is the dangerous part of the job. Minnesota has no state license to answer for that. In St. Louis County, just over half of homes heat with gas, so this is the kind of repair a lot of households here end up needing at some point.
Source: Minnesota Office of the Revisor of Statutes
- Why won't my furnace turn on?
- The most common cause is the thermostat not calling for heat, either from a dead battery or a setting that got bumped. After that, check your breaker panel, since a tripped furnace breaker will shut the whole system down with no warning. If power and the thermostat both check out, the igniter or the flame sensor may have failed, and a furnace won't run without either one working. A contractor can test each part to find out which one it is.
- Why is my furnace blowing cold air?
- Most of the time this means the blower is running but the burners never lit. A dirty flame sensor is a common reason for that, since it will shut off gas to the burners even when everything else is working. It can also mean the furnace is in the middle of its startup cycle, when cool air moves through the ducts for a short time before the burners kick in. If the air stays cold for more than a few minutes, the burners are not lighting and the furnace needs a look.
- Why won't my furnace pilot light stay lit?
- This is almost always the thermocouple, the small sensor that tells the gas valve the pilot is burning. When it wears out or sits out of position, it reads no flame even when there is one, and the valve shuts the gas off. A draft blowing across the pilot can cause the same thing, so it is worth checking that nothing is disturbing the flame. Either way, a furnace that won't hold a pilot needs a contractor to look at the thermocouple or the gas valve itself.