Heating: what to ask, what it costs, and one number to call
Updated June 2026 · By the Mobile Phonebook editorial team · How we research pricing
If it's happening right now: do this
- Smell gas, that rotten-egg odor? Don't flip switches, don't light anything. Get everyone out, then call your gas utility's emergency line from outside. That call outranks every contractor.
- Carbon monoxide alarm sounding, or unexplained headaches and nausea hitting the whole household? Get outside and call 911. CO is why heating problems are a different animal from AC problems.
- No gas smell, no CO alarm? Run the free checks: thermostat batteries, air filter, the furnace power switch (looks like a light switch near the unit), and the breaker.
- Hard freeze with the heat truly dead? Protect the pipes while you wait. Open cabinet doors under sinks and let faucets drip.
- Then call the number on this page. Say 'no heat' and your outdoor temperature. Most companies triage no-heat calls first in winter.
Heating contractors handle furnaces, boilers, heat pumps, and the no-heat calls that come with the first hard freeze. Common problems include ignition and pilot failures, blower motor issues, dirty flame sensors, thermostat faults, and the big one: aging furnaces at the repair-or-replace decision point. Gas furnaces also carry a safety dimension AC doesn't. Combustion, venting, and carbon monoxide.
That safety dimension is exactly what gets weaponized. The 'cracked heat exchanger' is the most famous scare diagnosis in residential HVAC. Sometimes it's completely real and genuinely serious. Sometimes it's a fiction used to condemn a working furnace and sell a new one the same afternoon. Knowing how to respond to that moment is worth more than anything else on this page.
What should you have ready before you call?
- Furnace age and fuel type (gas, electric, oil, heat pump); the manufacture date is on the data plate
- Make and model, ideally a photo of the data plate
- Symptoms: no heat at all, blowing cold, short cycling, won't ignite, strange smell or noise
- Whether you've checked the basics: thermostat set to heat, filter not clogged, breaker on, furnace switch on, gas supply working elsewhere (try the stove)
- Repair history, plus whether anyone has recently 'red-tagged' or condemned the unit
- Whether you have working carbon monoxide detectors
- Your rough plan: fix it to get through this winter, or open to replacement quotes
What should you ask before hiring? The 8-question script
This is your script. Nobody expects you to be an expert. Sound like someone who asks the right questions, and anyone good will answer all of these without flinching.
Baseline money question. Also ask the after-hours premium, since a no-heat call at 9 p.m. versus 9 a.m. can be a very different bill.
Flame sensors, igniters, capacitors, and pressure switches are the routine failures, and an honest tech will show you the part and the test. Vague 'it's shot' diagnoses deserve follow-up questions.
This is the most abused diagnosis in the trade. A legitimate finding survives scrutiny and a second opinion. A fake one evaporates the moment you ask for proof, and no reputable company objects to you verifying.
Having both numbers lets you run the age-times-repair-cost math on the spot instead of deciding under pressure.
A 96% AFUE furnace beats an 80% unit meaningfully in a cold climate, marginally in a mild one. Make the efficiency pitch show its work against your actual gas bills.
With current equipment and incentives, a heat pump is a legitimate option in much of the country. A contractor who can speak to both, with numbers, is showing you the whole board.
Condensing furnaces need different venting and a condensate drain. Quotes that skip those line items grow later.
Parts warranties often run 10 years but require registration. Labor coverage varies from 1 year to 10. Get both in writing.
How much does heating cost in 2026?
Routine furnace repairs mostly land in the hundreds. Replacements run into the thousands, priced by size, AFUE tier, and install complexity. 2026 national ranges:
| Typical job | National range | What moves the price |
|---|---|---|
| Diagnostic / service call | $75 – $200 | Cold-snap and after-hours calls run higher |
| Flame sensor cleaning or igniter replacement | $100 – $400 | The most common no-heat fixes |
| Blower motor replacement | $400 – $1,500 | Variable-speed motors at the high end |
| Control board replacement | $400 – $1,200 | Part availability varies on older units |
| Heat exchanger replacement | $1,500 – $3,500 | Usually only sensible under parts warranty; otherwise compare to replacement |
| Gas furnace replacement (installed) | $3,500 – $7,500 | Size, AFUE tier, venting changes |
| High-efficiency condensing furnace (installed) | $5,000 – $10,000 | Includes new PVC venting and condensate handling |
| Heat pump system (installed) | $6,000 – $16,000+ | Cold-climate and ducted systems run higher; incentives may offset |
| Boiler replacement (installed) | $4,500 – $12,000 | Fuel type and system complexity |
These are typical 2026 U.S. ranges for planning purposes; your market, season and job specifics can land outside them. Always get the price for your job confirmed on the call and in writing. Ranges compiled June 2026 from national cost data and industry sources (methodology).
When you don't need to call anyone
We get paid when you call, so take this section as seriously as we do. Sometimes the honest answer is that you can handle it yourself or fix it cheaper first:
- No heat? Check three free things first: thermostat batteries, the air filter, and the furnace power switch (it looks like an ordinary light switch, usually on or near the unit). They resolve a remarkable share of winter calls.
- Check the breaker too, and for gas furnaces, confirm the gas valve is on. Two more free minutes before a diagnostic fee.
- One cold room isn't a furnace problem. Look for closed or blocked vents and a dirty return before calling.
- System heating fine? You can do much of a 'tune-up' yourself (filter, clear vents). The part worth paying for on an older gas furnace is the safety inspection of the heat exchanger and venting.
How the heating business works
Heating companies run the same playbook as AC (often they're the same company): a diagnostic fee of $75-$200 to come out, flat-rate repair pricing from a book, and premiums for after-hours and cold-snap calls. The first freezing week of the season is their Black Friday. If your furnace was acting up in October, getting it looked at before the rush gets you better pricing and faster scheduling.
On repair-or-replace math: gas furnaces last roughly 15-20 years, sometimes more. The same rule of thumb as AC applies. Multiply age by repair cost, and if you're over $5,000, lean replacement. Furnace efficiency is measured in AFUE (annualized fuel utilization efficiency). Old units run 80% or below, while modern condensing furnaces hit 90-98.5%. The efficiency upgrade saves real gas money in cold climates and much less in mild ones, so make anyone selling on efficiency show the math for your actual heating bills.
Now the cracked heat exchanger. The heat exchanger is the metal barrier that keeps combustion gases out of the air blowing through your house. A genuine crack can let carbon monoxide in, and a furnace with one should be shut down. That part is true. The scam version goes like this: a tune-up tech 'finds' a crack, shows you a blurry photo that could be from any furnace, red-tags your unit, and quotes a replacement before dinner. Your move when anyone says these words is to ask to see the crack yourself, on camera, in your furnace, with the serial plate visible, and to get a second opinion before signing anything. A real crack will still be there tomorrow, and a second company can verify it in one visit. Keep CO detectors on every floor regardless; they're your independent check.
One more market shift worth knowing about: heat pumps. Modern cold-climate heat pumps heat efficiently well below freezing and can replace or supplement a furnace, and federal and state incentives have made them price-competitive in many areas. A heating contractor who flatly dismisses heat pumps without discussing your climate and electric rates is behind the market. One who pushes them without doing the math is just selling the newer thing. Either way, ask for both options priced when you're replacing.
Red flags & good signs
Red flags
- A cracked heat exchanger 'discovered' during a discount tune-up, with photos nobody can prove came from your furnace
- Red-tagging or condemning the furnace and pushing a same-day replacement signature. Real safety findings survive a second opinion.
- Carbon monoxide fear used as a closing tactic when no CO detector has ever sounded and no measurement was taken in front of you
- Refusing to show failed parts, combustion readings, or camera footage of the alleged problem
- Quotes that are one big number with no equipment model numbers, AFUE rating, or scope listed
- 'This price expires when I leave' on a multi-thousand-dollar replacement decision
- A new furnace pitch that never asks about your home's size, insulation, or existing ductwork
Good signs
- Shows you the failed part, the test readings, or the camera view of the actual problem in your unit
- Comfortable with you getting a second opinion on any condemnation or red tag
- Prices the repair and the replacement, and walks the math honestly
- Can discuss heat pumps and furnaces both, with numbers for your climate and rates
- Checks venting and CO at the visit, and recommends detectors without drama
Frequently asked questions
How much does a new furnace cost?
Should I repair or replace my furnace?
Is a cracked heat exchanger dangerous?
Why is my furnace blowing cold air?
What is AFUE and what rating should I buy?
Are heat pumps better than furnaces?
How long does furnace replacement take?
What do I do if my carbon monoxide detector goes off?
Related services
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