If your HVAC system is prone to frequent breakdowns and you’re calling your HVAC technician as frequently as you call for pizza, you can probably already guess the answer to the question in the headline. However, sometimes the decision to replace your HVAC system isn’t quite so obvious. 

Read further to educate yourself as to when your system might need some simple maintenance — and when it’s time to start researching replacement options.

Three Signs It’s Time to Replace Your HVAC System

There are three warning signs that indicate it’s probably time to replace your HVAC system:

1. Utility Bills Are Consistently Rising

Your HVAC system is easily the single greatest user of energy in your home and therefore will strongly influence your month-to-month utility bills. If you notice that your electricity or gas bill is higher than expected multiple months in a row, you may be dealing with an inefficient, outdated HVAC system. Regular maintenance helps to keep HVAC systems operating at their peak efficiency, but older systems may siphon more energy — and money— than you’d prefer. 

If you’ve had the same HVAC system for many years, compare your energy usage from a recent month to the same month’s usage in a prior year. You shouldn’t have a discrepancy of more than ten to fifteen percent.

2. Your HVAC System is More Than Ten Years Old

If your HVAC system is more than a decade old, you need to start planning for a full HVAC system replacement. HVAC systems installed prior to 2010 use a refrigerant known as R22 (or Freon), which has been banned (except for servicing existing equipment) in the United States because of its polluting properties. 

A complete ban on R22 will take place beginning January 1, 2020, meaning older HVAC systems using R22 cannot be serviced. Moreover, the industry replacement for refrigerant, R410A, is incompatible with R22. A replacement system is the only option for these older systems. 

3. The Temperature in Your Home is Not Comfortable

A telltale sign that an HVAC system is on its way out is its inability to keep a home at a consistent, comfortable temperature. While minor issues — such as damaged thermostats, air leakage in the ducting, or clogged filters — will contribute to inconsistent or erratic temperature control, you might also have serious component damage. 

Your HVAC system may not have been designed for the space it’s currently trying to cool and heat, or the ducting may have been improperly installed. Believe it or not, a larger HVAC system is not always the best one. A too-large air conditioner might cool a house quickly, but it will struggle to keep relative humidity below 60%, and oversized heaters tend to leave some rooms extremely hot and others very cold. 

Note: Before you call for a technician to check the system, first check that the circuit breakers and the power switch are in the correct positions.

Signs to Watch Out For

If you’re concerned about whether you need to replace your HVAC system, pay attention to anything unusual. Here are a few pointers:

• If you notice an increase in dust accumulation around vents and in your home or an unusual smell lingering for days, you need to act sooner rather than later. Call a technician and schedule a consultation to find out what’s going on.
• Weak airflow out of one or two rooms is likely a sign of a blocked duct, whereas weak airflow in every room could signify that the compressor is struggling. 
• Excessive humidity in summer and excessive dryness in winter could spell various ducting issues. Many times, these issues (and those above) can be resolved with a thorough cleaning from a professional technician, but in more serious cases, they are the harbingers of a system nearing the end of its life.
• Odd sounds are more imperative to examine before a lingering annoyance becomes a serious issue. Squealing noises are often related to belts that have slipped and therefore should be replaced. Grinding sounds typically correlate to worn-out or broken motor bearings.
• Short-cycling is an obvious indicator that your system is not working as designed. A short-cycle occurs when your system turns on and off in short intervals, often in succession. When a system short-cycles, it could be a sign that the heat exchanger is overheating, the coils are frozen, the compressor is malfunctioning, the refrigerant is not charged enough, or other mechanical issues have arisen. Short-cycling when the furnace is on is another sign that your system is too large.

Repair, Retrofit, or Replace?

Before you take the plunge and purchase a new system, call a certified professional technician and schedule a full energy assessment. The technician will inspect your air conditioner to see if it has a Seasonal Energy Efficiency Rating (SEER) below 13; all modern air conditioners must have a rating above that. 

Another marker to check is your system’s annual fuel utilization efficiency (AFUE), or the percentage of the energy used by your system converted to heat. A technician can measure the AFUE, which should be 90% or higher, and help you decide whether you ought to make certain repairs or prepare for a full replacement. 

One option for those that may not have the money for a complete overhaul but need to make short-term fixes is to retrofit an older HVAC system. Adding vent dampers to gas- or oil-burning boilers and furnaces will prevent heat from escaping up chimneys when the system is not in use. Reducing the size of nozzles and baffles and eliminating redundant radiators can downsize a system that’s too big for a home. Time-delayed relays for hot-water heaters allow hot water to circulate throughout a system without necessarily using the boiler. These are but a few options your technician might suggest.

The U.S. Department of Energy suggests that furnaces and boilers be replaced at least once every fifteen years; for air conditioning systems, the recommendation is every ten years. A new HVAC system ranges on average from $6,000 to $8,500, with any necessary additional ducting adding several thousand dollars on top. 

Make sure to do your research on potential savings before investing in a new system. Energy Star-stamped HVAC systems can net a future tax credit of up to 30%, and your energy company might offer a one-time incentive to upgrade to a more energy-efficient HVAC system. The U.S. Department of Energy suggests that modern HVAC systems can achieve efficiencies as high as 98 percent! You could save some serious cash on your energy bill by upgrading to a more efficient system.

Final Considerations

One handy rule of thumb if your HVAC system is in need of a major repair and is more than a decade old: If the repairs will cost more than half of what a new system would cost, your wiser investment would be with the new system. And finally, don’t try to DIY your way out of an HVAC problem. Trust me; you’ll end up wishing you had called a professional in the first place.