HVAC questions Fort Worth homeowners ask us

With the thermostat set to cool at a realistic temperature, the system should run until your home reaches that temperature and then cycle off within 30–45 minutes, if not sooner. Outdoor and starting indoor temperature both affect that without meaning anything is broken.

For example: if the system has been off for an extended period and the inside temperature has climbed to roughly 85°F or higher, setting the thermostat to 72°F will most likely take several hours to reach. That isn’t necessarily a fault.

A better test is to measure the temperature drop. Put a thermometer at the return air grill — the one sucking air in, not blowing it out — leave it in place for 3–5 minutes, and note the temperature. Then place the same thermometer at a few different supply grills, again leaving it for 3–5 minutes each. If the difference between the return and the supply grills is around 15–20 degrees, your system is more than likely performing properly.

Work through these in order before you call:

1. Check the thermostat. If it doesn’t display, change the batteries (if it has them).
2. If there’s still no display after changing the batteries, check the fuse box.
3. If no fuses have blown or tripped, your thermostat may need to be replaced.
4. If the thermostat is working but the AC isn’t, check your filter — if it’s dirty, replace it with the same size.
5. If it still isn’t cooling properly, turn the thermostat to fan and wait about 30 minutes to an hour, then turn it back to auto. A dirty air filter prevents airflow and over time can ice up the indoor coil, which stops cold air from blowing.
6. If all else fails, call us for expert repair.

If it’s already hot inside and the system is down, read what to do before we arrive.

The condenser coils can freeze up and prevent cooling — usually because the filters are dirty or debris is obstructing airflow from the outdoor unit. Low refrigerant can also cause it. We diagnose the cause, de-ice the coils, and fix what led to it rather than just thawing it out. More detail in why AC units freeze up in spring.

Refrigerant leaks. Refrigerant can leak through damaged lines in the system, resulting in less pressure during the cooling process. Our technicians detect the source of the leak, repair it, and recharge the entire system to ensure the proper amount of refrigerant is added.

Frozen condenser coils. The coils can freeze and prevent cooling, usually from dirty filters or debris obstructing airflow at the outdoor unit; low refrigerant is another cause. We diagnose the problem and resolve it by de-icing the coils and correcting the cause.

Blocked drain lines. The drain line and drip pan can become damaged or obstructed with algae, preventing moisture from draining — which shows up as high indoor humidity or damage to the unit. We clear or repair those components so condensation can exit the system again.

No. Each refrigerant is designed to operate at a particular pressure during operation. These two refrigerants have different properties and are not interchangeable. The compressor and other components may be damaged if you change the refrigerant.

We repair and service every major brand, whatever equipment you already own. American Standard is the one brand we install when it’s time for a new system — but that has no bearing on whose equipment we’ll work on.

There are many types of air conditioning systems, including:

• Central air and heat — split systems or package units, the most common in residential homes; straight cool with straight electric heat
• Heat pump systems with backup electric heat
• Straight cool systems with gas or propane heat
• Dual fuel systems
• Ductless, mini-split air conditioners
• Geothermal heating and cooling (less common in southern states)

Regular maintenance keeps a system running efficiently and catches smaller issues before they grow; a repair addresses something that is already failing. If you’re not sure which side of the line your system is on, this guide walks through the difference, or see our maintenance plans to have it handled on a schedule.

When repair calls are getting more frequent, cooling is uneven, or energy bills are climbing without a clear reason, it’s worth running the numbers before you spend on another fix. We give free estimates on replacements and free second opinions, and financing is available with approved credit (WAC). See when repair doesn’t make sense and our AC installation page.