When your old air conditioner needs maintenance or repairs, the decision whether to go ahead with repairs or to replace it entirely comes down to factors like how well your current air conditioner is working, which parts specifically need work, and the cost of repairs compared to how much money you can save with an ac replacement.

Check Efficiency Over Time

Air conditioners gradually lose efficiency over time, and the amount by which its efficiency has decreased can sometimes make all the difference. For example, if your air conditioner is nearing the end of its lifespan but still runs well and hasn't added too much to your electric bill with time, it might end up being more cost effective to get simple repairs done now and worry about replacing it later. If its efficiency has taken a noticeable drop, however, it's a good idea to start looking into what your next air conditioner will be.

In general, replacing your air conditioner slowly becomes a more viable option the older it gets, but if you can still get a few more years out of your current unit without paying too much extra for regular use, you can focus more on immediate fixes.

Look at What Needs Work

The problem itself can influence what your best option is. For example, if the problem you're experiencing is related to one of the air conditioner's components, such as its ducts—which can quickly start losing plenty of air—your efforts are best spent on fixing those components rather than replacing the air conditioner they're connected to. If there's a serious problem with the unit itself, such as internal parts failure, you'll get much more utility out of replacing your air conditioner then.

The severity of the issue impacts this as well, but once you start seeing recurring problems with your air conditioning unit itself, any future repairs quickly start becoming less cost effective.

Cost of Repair vs Savings From Replacement

One final way to decide what to do is to look at how much you expect repairs to cost compared to how much money you could save by replacing your unit. Energy efficiency is one factor, but potential future repairs are another; if you have to keep repairing your older unit, that's all money that could be going toward a replacement instead. When factoring in the cost of repairs, it's important to add that to the cost of a replacement unit; your air conditioner will inevitably need to be replaced, so any repairs you make in the meantime are added to that cost.

This can sometimes end up working out if you're looking at minor repairs here and there in a unit that otherwise runs well. With more serious problems, however, doing a little math can help. Forgoing repairs and making the up-front cost of a new unit is more money spent in the short term, but can be much more effective in the long term.

One thing you can do here is to ask your HVAC technician for an estimate on how much longer you can expect your air conditioner to last based on the kind of work it needs and the state of its components. This can often help you decide which option is more cost effective.