Repair or replace? How to know when it’s time for a new AC or heat pump

Replacing a heating and cooling system is one of the bigger checks a homeowner writes, and the decision often has to be made in a hurry when something breaks. Knowing the signs ahead of time makes it a lot easier to decide calmly.

Signs it may be time

• Age: ENERGY STAR suggests considering replacement when an air conditioner or heat pump is more than 10 years old, or a furnace or boiler is more than 15 years old. Many systems last longer, but efficiency and reliability drop with age.
• Frequent repairs, especially several in the same season.
• Rising energy bills without a change in how you use the system.
• Rooms that are always too hot or too cold, or humidity problems.
• It uses R-22 refrigerant and needs a repair involving refrigerant. R-22 is no longer produced, so those repairs are costly.
• A major failure on an older unit, such as the compressor on the AC or the heat exchanger on a furnace. A cracked heat exchanger is a safety issue, not just a cost issue.

Check the warranty first

Many systems carry parts warranties of 10 years or more if they were registered after installation. A big repair on a newer system may be mostly covered, though labor often isn’t. Find your paperwork or ask the installing contractor before you decide.

What a good replacement quote looks like

• Sizing based on a load calculation (often called Manual J), not just matching the old unit’s tonnage. An oversized system short-cycles, wears out faster and handles humidity poorly.
• Exact model numbers for the outdoor unit, indoor coil or air handler, and furnace, ideally as a matched system with an AHRI certificate showing its efficiency rating.
• Efficiency ratings: SEER2 for cooling and HSPF2 for heat pump heating. Since 2023, most new split air conditioners sold in the Southwest (Arizona, California, Nevada and New Mexico) must be at least 14.3 SEER2. Higher ratings cost more up front and save more over time, so ask for the payback math.
• An assessment of your ductwork. A new system on leaky or undersized ducts won’t perform the way its rating suggests.
• Permits, removal of the old equipment, and refrigerant recovery included.
• Labor warranty terms in writing, plus registration of the manufacturer’s warranty.

Refrigerant and incentives

• New systems now use refrigerants such as R-454B or R-32. Some contractors still have R-410A equipment built before 2025, which can legally be installed. Ask which refrigerant you’re getting and what that means for future service costs.
• The federal energy-efficient home improvement tax credit (Section 25C) ended for equipment installed after December 31, 2025. Check with your electric or gas utility for rebates, and ask a tax professional about anything else that may apply.

When to repair instead

If the system is under about 10 years old, has been reliable, and the repair is a common part like a capacitor, contactor or fan motor, repairing it is usually the smart move.