There are few things as distressing as an HVAC unit that’s not doing its job. Heat pumps, air conditioning units, furnaces, and other systems are major investments, and not something that most home owners look forward to replacing.

If your system needs attention, find a reputable company that does AC repair. Until then, here’s a list of possible issues that might be causing your HVAC unit to fall down on the job:

The Unit is Wrong for Your Home

Believe it or not, sometimes the main reason why energy bills soar but the home never feels comfortable is that the wrong unit was installed. Not every HVAC system is right for every home, and bigger isn’t always better.

EnergyStar.gov explains that an AC unit that’s too large is actually less effective than one that’s the right size. It might make the room cold quickly, but energy bills will be higher and excess humidity can become a problem.

When choosing a unit for your home, the square footage is only one factor. Climate and the level of insulation in the home are also important considerations.

A Tune-up is Needed

If the HVAC unit hasn’t been serviced in a year or more, it’s past time to schedule an appointment. Heat and air conditioning work constantly through their respective seasons, and that’s a lot of wear and tear. Regular maintenance (ideally one system check for cooling season and one for heating season) will maximize your system’s performance and lifespan and minimize repair costs.

Ductwork is Inadequate or Damaged

Ductwork is the pathway from your heat and air unit to the rooms in your home. If all or part of the ducts are damaged or inadequate, even the best system can’t make your home as comfortable as it otherwise could.

You can inspect part of your ductwork using a flashlight. But if you have minimal access, a professional might be required to make an assessment. They’ll check for damage , and can also determine whether adding more ductwork could improve the comfort in your home.

Refrigerant is Low

Although an air conditioner is a sealed system leaks can cause it to lose charge. If it’s low on refrigerant, you’ll turn the thermostat lower and lower, and see minimal results.

Adding refrigerant is not a DIY job because you must have a license in order to purchase it. So, if your system requires refrigerant, you’ll need to call a professional.

There is Heat Transfer

Drafts or air leaks are the equivalent of trying to heat or cool the outdoors. Heat that transfers in during summer makes your air conditioning work harder than it should and heat that escapes out during cold weather has the same effect on your heat system.

Sealing up air leaks keeps conditioned air where it belongs — indoors. There might be nothing wrong with your unit at all, but it may feel that way if some of its hard work is escaping through the cracks in your home.

Ideally, an HVAC system is something you purchase, maintain regularly, and enjoy with few problems. But when you can’t count on it working like it should, it’s time to find out why.

The problem might be as simple as a tube of caulk to seal up a few drafts or it might be something a bit more involved. Take an assessment of your home, and then call a professional to check your system. You might not need a major repair. But if you do, handling it sooner rather than later will save money on energy bills and make your home more comfortable in every season.