How does a furnace repair visit work?
- Book the visit. Call 612-429-3465 or send the form. We're open 7 days a week, 7am–9pm, and no-heat calls go first.
- Tell us what you saw. A blink code, a noise, how long the burners stayed lit. Those details point the technician in the right direction before the panel comes off.
- We watch the startup sequence. A gas furnace lights in the same order every time. The thermostat calls for heat, the inducer motor starts pulling air through the heat exchanger, and the pressure switch closes once it senses that draft. The hot surface igniter glows, the gas valve opens and the burners light. The flame sensor proves the flame, and after a short delay the blower comes on. A limit switch watches the temperature the whole time. Where the sequence stops tells us which part to test.
- We test before we replace. The suspect part gets checked with a meter, and gas pressure and draft with a manometer, so you don't pay for parts you didn't need.
- You approve a written price. The repair is a flat-rate price for parts and labor, and the $79 trip charge is waived when you say yes.
- We repair it and prove it. The furnace runs through full cycles while we check the flame, the temperature rise and carbon monoxide around the furnace and flue. The repair carries a written 1-year parts-and-labor warranty.
Symptoms, likely causes and what we do
| What you notice | Likely cause | What we do |
|---|---|---|
| Nothing starts, not even the inducer | No power, a thermostat or wiring fault, an open door switch or a blown fuse on the board | Check power, the thermostat circuit, the door switch, the fuse and the transformer |
| Inducer runs, igniter never glows | Pressure switch not closing (blocked vent or intake, plugged condensate trap, cracked hose, weak inducer), or a cracked igniter | Check the draft and hoses first, then test the switch and the igniter |
| Igniter glows, burners never light | Gas turned off, low gas pressure or a failed gas valve | Check the gas supply and pressure, then test the valve |
| Burners light, then go out after a few seconds | A coated flame sensor, a poor ground or low gas pressure | Measure the flame signal, clean or replace the sensor, check gas pressure |
| Runs a few minutes, shuts off, repeats | Limit switch tripping from a clogged filter, closed registers or a weak blower | Check the filter, airflow and temperature rise before touching the switch |
| Blower runs but the air is cold | The furnace locked out after failed starts, or the thermostat fan is set to On | Read the lockout code and trace the step that failed |
| A boom as the burners light | Delayed ignition from dirty or misaligned burners, or low gas pressure | Clean and adjust the burners, check gas pressure and the heat exchanger |
| Water around a high-efficiency furnace | Plugged condensate trap or drain, a failed condensate pump, a frozen line or a humidifier leak | Clear or repair the drain, then check the control board for water damage |
Two of these are everyday winter calls. Our guides to cleaning a flame sensor and the furnace limit switch cover them step by step, including what's safe to check yourself.
Short-cycling has more than one cause
A furnace that turns on and off every few minutes is wearing itself out, and the cause decides the fix. A coated flame sensor causes the shortest version, where the burners go out seconds after lighting. An overheating limit switch causes the longer version: the furnace runs a few minutes, trips, cools and starts again, often with the blower still running. An oversized furnace does it too, because it heats the air around the thermostat before the rest of the house catches up, and so does a thermostat mounted near a supply register or in direct sun. We sort out which one you have before recommending any part. Our post on furnace short-cycling shows how to time a cycle so you can tell us what you're seeing.
What about cracked heat exchangers, carbon monoxide and red tags?
The heat exchanger keeps combustion gases separate from the air your blower pushes through the house. When it cracks, those gases, including carbon monoxide, can reach your living space. Warning signs include burner flames that jump or change shape when the blower starts, rust or soot around the burners, a rollout switch that keeps tripping, and a CO alarm going off. Our post on cracked heat exchanger symptoms covers how a crack is confirmed.
If we confirm a crack or find flue gas spilling into the house, we shut off the gas to the furnace, tag it and walk you through what we saw. That's a red tag, and the furnace should stay off until it's repaired or replaced. Minnesota law requires working CO alarms within 10 feet of every sleeping room (Minn. Stat. 299F.51). If yours are missing or past their replacement date, replace them before the next cold night.
Winter failures we see in Minnesota
Minnesota winters bring their own set of calls:
- Frosted or buried PVC pipes. On high-efficiency furnaces, frost builds on the intake and exhaust outside, or drifting snow covers them, and the pressure switch shuts the furnace down. Clearing them often brings the heat back. If they keep frosting over, the termination placement needs a look.
- Frozen condensate lines. A drain that runs through a cold garage or crawlspace freezes and backs water into the furnace. Our guide to a frozen condensate line walks through the fix.
- Worn parts giving out. Long run hours through January finish off inducer bearings and igniters that were already weak in October.
- Propane run-outs. In the rural towns and lake areas at the edge of our service area, a tank that runs empty locks the furnace out, and the propane supplier usually has to leak-check the system before relighting. If the furnace still won't fire after that, we take it from there.
- Humidifier leaks. A whole-home humidifier works hard through a dry Minnesota winter. When its drain plugs or its water valve sticks open, water can end up inside the furnace cabinet, and water on a control board can ruin it.
- Older city houses. In pre-war houses, the furnace often feeds ductwork left from an old gravity system or shares a masonry chimney with the water heater, so we check airflow and draft along with the furnace itself.
If you smell gas, leave the house and call your gas utility from outside before you call us: CenterPoint Energy in Minneapolis, Xcel Energy in Saint Paul, or your propane supplier. We handle furnace repair in Minneapolis and Saint Paul and in every town within about 50 miles, from the Wright County lakes to Hudson and River Falls in Wisconsin.
Brands and older furnaces
We repair every major brand, including Carrier, Trane, Lennox and Goodman, along with Bryant, Amana, York, Rheem and the rest. Modern gas furnaces use the same kinds of parts in the same startup order, so the diagnosis works the same way whatever the badge says. Older furnaces with a standing pilot or a spark-lit pilot still heat some Minnesota basements, and we work on those too, though parts for some discontinued models are getting hard to find. When an exact part is no longer made, we'll say so and price a universal part or a replacement.
How much does furnace repair cost?
With us, a repair visit is a $79 trip charge, waived when you approve the repair. After we find the problem, you get a written, flat-rate price covering parts and labor before we start. Pricing is the same in every town we serve, with nothing added for distance, and completed repairs carry a written 1-year parts-and-labor warranty.
For scale, national cost guides report the ranges below. These are typical national figures from HomeGuide's cost guides, and your own repair is priced in writing once we find the problem.
| Repair | Typical national range (HomeGuide) |
|---|---|
| Flame sensor replacement | $80–$250 |
| Hot surface igniter | $100–$250 |
| Limit switch | $100–$375 |
| Pressure switch | $150–$400 |
| Gas valve | $200–$800 |
| Control board | $300–$650 |
| Inducer (draft) motor | $400–$1,100 |
| Blower motor, PSC | $500–$1,400 |
| Blower motor, variable-speed ECM | $800–$2,300 |
| Heat exchanger | $1,000–$3,000 |
Flame sensor cleaning is normally part of a tune-up, which starts at $129 with us. Our furnace repair cost guide covers these repairs in more detail, the blower motor cost guide explains PSC versus ECM motors, and the Minneapolis HVAC cost page and pricing page list our published prices.
If a repair doesn't make sense on an old furnace, we'll say so and quote a replacement. Installed furnaces run $4,500–$9,500 with us, and our furnace replacement page explains where a home lands in that range. Call 612-429-3465 or use the form to book.
What's included with furnace repair?
- Sequence-of-operation check from the thermostat to the blower
- Flame sensor, igniter, inducer, pressure switch and limit testing
- Carbon monoxide check around the furnace and flue
- Written, flat-rate repair price before any work starts
- $79 trip charge waived when you approve the repair
- Written 1-year parts-and-labor warranty on the completed repair
- Same pricing in every town we serve, with nothing added for distance
Furnace Repair questions
Why does my furnace light and then shut off after a few seconds?
Most often the flame sensor is coated and can't prove the flame, so the control board closes the gas valve as a safety. Cleaning or replacing the sensor usually fixes it. The same pattern can come from a poor ground, low gas pressure or a failing control board, which is why we measure the flame signal instead of guessing. If you try cleaning the sensor yourself, shut the power off first.
Why is my furnace blowing cold air?
Usually the burners aren't lighting or the furnace has locked itself out, and the blower is moving unheated air. Check that the thermostat fan is set to Auto, not On, since On runs the blower between heating cycles. On a high-efficiency furnace, look for snow or frost on the PVC pipes outside. If the control board is flashing a code, note it before you call, because it tells us which step failed.
What do furnace noises mean?
Most noises point to one part. A squeal or howl at startup is usually worn bearings in the inducer or blower motor. A boom as the burners light is delayed ignition, where gas builds up before it catches, often from dirty burners, and it should be checked soon because it stresses the heat exchanger. A rattle can be a loose panel or a failing inducer, and a hum with no blower can be a motor or its capacitor.
What is a red tag?
A red tag means a technician found a hazard, shut off the gas to the appliance and tagged it so nobody turns it back on. The usual reasons are a cracked heat exchanger, flue gas spilling into the house or a gas leak. You're entitled to see exactly what was found. The furnace should stay off until the problem is repaired or the furnace is replaced.
Can a cracked heat exchanger be fixed?
Not by patching it. A crack lets combustion gases, including carbon monoxide, mix with the air your blower sends through the house. The fix is a new heat exchanger or a new furnace. Many manufacturers cover heat exchangers for a long time, so check your warranty registration, but the labor to swap one is heavy. On a furnace past about 15 years old, replacement usually makes more sense.
Is it worth repairing an old furnace?
It depends on the part and the age. An inducer motor, igniter or blower motor on a 10-year-old furnace is a normal repair. The same repair on a 22-year-old furnace buys time, but it may be the first of several. We can give you the repair price and a replacement price in writing, so you can decide with both numbers in front of you.
What should I check before I call?
Make sure the thermostat is set to heat and above room temperature, the switch on or near the furnace (it looks like a light switch) is on, the filter isn't packed solid, and the white PVC pipes outside aren't buried in snow. Don't keep resetting a furnace that locks out. If you smell gas, leave the house and call your gas utility from outside.
Do you repair furnaces in Wisconsin too?
Yes. We're licensed in Minnesota and Wisconsin and cover Hudson, River Falls, Prescott and the Town of Oak Grove on the Wisconsin side, along with the rest of our service area. The $79 trip charge, the written flat-rate price and the 1-year repair warranty are the same on both sides of the St. Croix.
Sources
- Minn. Stat. 299F.51 revisor.mn.gov
- HomeGuide cost guides (2026 editions) homeguide.com