Gas Furnace Repair vs. Replacement: Which Is Best?

When a chilly Tempe evening hits and your gas furnace won’t ignite, you’re facing more than discomfort—you could also be dealing with higher utility bills and safety risks. As a family-owned team serving Tempe since 1988, Savage Air Conditioning has helped thousands of East Valley homeowners make the smart call on repair vs. replacement—before small problems turn into mid-season emergencies.

Safety first. If you smell gas, hear hissing, or your carbon monoxide (CO) alarm sounds, leave the home immediately and call your gas utility or emergency services. Do not attempt to troubleshoot the furnace. After the home is safe, contact a licensed HVAC professional.

When to Repair Your Gas Furnace

Repair makes sense when your furnace is relatively young and the fault is isolated. If a single component—like an igniter, flame sensor, control board, or blower motor—fails while the rest of the system is in good condition, a professional repair is often the most cost‑effective path.

Good candidates for repair typically include systems that are under ~10 years old and properly maintained, show stable energy bills and reliable performance between tune‑ups, and have no combustion or venting concerns—systems that pass all safety checks. Are under ~10 years old and have been properly maintained Show stable energy bills and reliable performance between tune‑ups Have no combustion or venting concerns and pass safety checks

During a repair visit, a Savage Air Conditioning technician will verify proper combustion, draft, and venting; gas pressure and burner performance; heat exchanger integrity and the absence of CO; and the correct operation of safety devices and controls.

Homeowner tip: Avoid relighting pilots, bypassing safeties, or opening panels yourself—especially if there’s any gas odor or a tripped safety.

When Replacement Is the Better Option

Consider replacement when the system is old, inefficient, unreliable, or unsafe. If your furnace is 15–20+ years old, breaking down more often, or driving up gas bills, it’s likely nearing end‑of‑life.

Issues that often point to replacement: cracked heat exchangers or failed venting that create safety hazards; frequent repairs or major component failures (for example, a control board plus an inducer); noticeably rising energy bills despite regular maintenance; and uneven comfort or persistent reliability problems. Cracked heat exchanger or failed venting (safety hazards) Frequent repairs or major component failures (e.g., control board + inducer) Noticeably rising energy bills despite regular maintenance Uneven comfort or persistent reliability problems

Benefits of upgrading now: higher efficiency that lowers energy use, stronger and more even heat with better airflow, improved safety with modern protections and proper commissioning, and a reduced risk of mid‑season breakdowns. Higher efficiency and lower energy use Stronger, more even heat and better airflow Improved safety with new safeties and proper commissioning Reduced risk of mid‑season breakdowns

Savage Air Conditioning will handle permitting and code compliance, and we’ll commission the new system to manufacturer specs for safe, reliable operation.

Repair vs. Replacement: Key Variables to Evaluate

Age & Condition. Older units lose efficiency and develop wear‑related issues. If you’re scheduling frequent service visits or facing high repair bills, that’s a red flag.

Cost Curve. Compare the repair estimate against the installed price of a new system and factor in expected efficiency gains.

Time Horizon. If you’ll be in the home long‑term, a replacement can pay for itself in energy savings and reliability. Moving soon? A targeted repair may be sufficient.

Safety & Comfort Goals. Any CO risk, failed venting, or unreliable heat is a non‑negotiable reason to upgrade. Ensure working CO detectors on every level and outside sleeping areas.

What It Means for Homeowners in Tempe, AZ

East Valley winters are short—but when the temps dip, you want consistent, safe heat. Local factors like venting design, gas supply, permits, and city code all matter. Choosing a local provider like Savage Air Conditioning means you get a crew that knows Tempe homes, pulls the right permits, and delivers fast, reliable solutions rooted in decades of local experience.

FAQs About Furnace Repair & Replacement in Tempe, AZ

How much does a furnace repair cost in Tempe?

Most repairs range from a few hundred dollars to over $1,000, depending on the part and labor involved. For safety, have a licensed technician diagnose the issue rather than attempting DIY repairs.

How much does replacing a gas furnace cost?

Costs vary, but expect a range between $3,500 and $10,000+, depending on efficiency and home size. Proper installation, commissioning, and permits are essential for safe operation and warranty protection.

Should I repair or replace my furnace if it’s 12 years old and just had a $900 repair?

You’re at a turning point. If the furnace is otherwise reliable, repair may be fine. But if more repairs are likely or performance is dropping, consider replacement. Always prioritize safety findings (like heat exchanger issues or venting problems) over short-term savings.

Can I wait until next winter to make the decision?

You can, but doing so risks more damage or a total failure when you need heat the most. Acting now gives you control and better pricing. At minimum, schedule professional maintenance before the heating season and ensure your carbon monoxide detectors are installed and functional.

What efficiency gains can I expect with a new high-efficiency gas furnace?

New systems can reach 90%+ efficiency, compared to 60-80% for older models. That means less waste, lower bills, and more comfort, especially when the system is properly sized and installed by qualified professionals.

What should I do if I smell gas or suspect a carbon monoxide issue?

Leave the home immediately, avoid using electrical switches or phones inside, and call your gas utility or emergency services from a safe location. Once cleared, contact a licensed HVAC professional for inspection. Do not attempt to relight or service the furnace yourself.

Did You Know? (Expert Rule of Thumb)

If the repair cost exceeds ~50% of a comparable new system—or the furnace is 15+ years old—replacement is usually the smarter long‑term move. Regardless of cost, confirmed safety issues (like a cracked heat exchanger or failed venting) require professional correction and may necessitate replacement.

Final Recommendation

If your furnace is under 10 years old, has minimal repair history, and your bills are stable, a repair is usually the sensible choice. If it’s 15 or more years old, unreliable, inefficient, or showing safety concerns, replacement is the smarter long‑term investment.

Schedule Your Inspection

Call our team or use the Schedule Service form to book an appointment at a time that works for you. Ask about our Home Wellness Club if you’d like a preventative plan to keep your system tuned and safe year‑round.