While much of the country may think we live in a frozen tundra, we Minnesotans know differently. We look forward to our steamy hot summers every year. When we’re not basking in the sun, we absolutely love the feeling of a cold burst of air when taking refuge in our homes.

But when your central air conditioner is on the fritz, it’s hard to remember that you’d been wishing for these hot temps all winter long.

Welter Heating has been in the heating and cooling business for more than 100 years, and every spring and summer we field calls from stressed out homeowners wondering if they’re in need of air conditioning repair. Below are answers (and repair tips) to some of those most commonly asked questions about residential air conditioning repair.

1. How can I tell if my air conditioner is broken?

If the cool air has stopped flowing, the first thing you should do is check your thermostat.

Here are the steps you should take:

• If your thermostat display is blank, change the batteries.
• If the display is still blank, remove the thermostat from the wall and check the wires to make sure it’s getting power. Use a multimeter to check the voltage.
• If you’re not getting voltage, check your fuse box to see if any fuses have been blown or tripped. If the fuses look good, locate the switch connected to your central A/C and switch it on and off to reset the connection.
• If it’s getting power, but the screen is still blank, go outside and check the condenser to see if a fuse has been tripped.
• If your thermostat still isn’t working, it may be time to replace it. Check the warranty to see if it’s expired.

If your thermostat is working, but the air conditioner won’t turn on, you should also:

• Turn on the fan to see if the blower is getting power.
• Change your air filter if it’s more than one month old. The buildup of dirt and debris could be preventing air flow.
• Check the condensation drain.

You can also check our air conditioner troubleshooting guide for more repair tips. If you’re still experiencing problems, call an HVAC professional.

2. When should I replace my air conditioner?

Replacing your air conditioning system is an investment.

Here are some things to consider:

• The age of your air conditioner. The life of an air conditioner is somewhere between 10 and 20 years. So, if your air conditioner is more than 10 years old, it may be time for a replacement.
• Rising energy bills. As air conditioners get older, they become less energy efficient. To see if your air conditioner is losing efficiency, compare your utility bills over the past few summers. If your costs are rising, it could be a sign that your air conditioner is wearing out.
• Leaking refrigerant. Not only is refrigerant expensive, but refrigerant leaks will cause the compressor to eventually go out. The type of refrigerant that your air conditioner needs may also cause you problems down the road.
• The cost of repair. Call your local HVAC company to get a free quote on repair costs. If it’s more than $3,000, it is probably cheaper to buy a new unit.

3. Why is my air conditioner freezing up?

Nearly all air conditioner freeze ups are caused by either a lack of refrigerant, or a lack of air flow to the evaporator coils. If your air conditioner is freezing up, the first thing you should do is turn it off. If you continue to run it, the compressor could be damaged.

Troubleshoot by checking the following items:

• Thermostat temperature setting. If your thermostat is set below 70 degrees it could be causing your air conditioner to freeze up — and it’s actually not cooling your home any faster.
• Refrigerant level. If your refrigerant level is low, this could signal a larger issue and we’d recommend calling a professional to have a look.
• Air filter. A clogged, dirty air filter could be causing the issue. As mentioned above, change the filter if it’s been more than a month since the last change.
• Vents. Make sure all vents are open to ensure air flow to the evaporator coil.
• Evaporator coils. If the evaporator coils are blocked by dirt and debris, this could be cause of the problem.
• Fan. Your fan is what blows cool air through the ductwork in your home — and also helps circulate air back to your evaporator coil.

Read “Why is My Air Conditioner Freezing Up?” for more details.

4. Why is my air conditioner leaking condensation? Should I be worried?

One function of A/C units is to extract humidity from the air, so a little bit of condensation is natural. However, leaks usually indicate that there’s a problem with the way the condensate is draining.

The following things could be causing this issue:

• A clogged condensate line.
• A rusty condensate pan.
• A dirty or frozen evaporator coil.
• A low refrigerant level.
• Dirty air filter.
• Installation issues.

For tips on how to investigate each of these, check out our troubleshooting article “My Air Conditioner Is Leaking Condensation. Now What?”

5. How do I change my air filter?

As mentioned above, you should regularly change your air filter to ensure the air conditioner is running efficiently — and not contributing to other maintenance problems.

To change your filter, follow these steps:

• Choose the right size. Remove your old filter and measure it, or read your user’s manual.
• Choose a MERV. MERV stands for “minimum efficiency reporting value” and ranges from 1-20. The higher the MERV, the more effective the air filter.
• Choose the type of filter. You can choose from fiberglass, washable, pleaded or electronic.
• Install it. Most air filters are extremely easy to install. Follow the manufacturer’s instructions.

Get more details on this topic be reading “How to Change Your Air Conditioning Filter.”

If you have another question about air conditioning repair, contact us today. We’re ready and willing to help.