Siegman & Schaefer (Siegman Forced Air Systems, Inc.) is a veteran-owned plumbing and HVAC company serving Southern Pennsylvania and Northern Maryland since 1992. Before you call for AC repair, run through these seven checks — some you can fix yourself in minutes.
1. Check Your Thermostat Settings
This sounds obvious, but it's the most common "AC problem" we see. Make sure your thermostat is set to COOL (not HEAT or OFF) and that the temperature is set below the current room temperature. Also check that the fan is set to AUTO, not ON. When set to ON, the fan runs continuously — even when the AC isn't actively cooling — which can make it feel like the system is blowing warm air.
If you have a programmable or smart thermostat, check the schedule. Someone may have changed the settings, or the thermostat may have reverted to a default schedule after a power outage.
2. Check Your Air Filter
A dirty air filter is the single most common cause of AC performance problems. When the filter is clogged, airflow is restricted, which forces your AC to work harder and can cause the evaporator coil to freeze. The result: warm air blowing from your vents, or the system shutting down entirely.
What to do: Pull out the filter and hold it up to a light. If you can't see light through it, replace it. Standard 1-inch filters should be replaced every 30 to 60 days during cooling season. Media filters last longer — check the manufacturer's recommendation.
3. Check Your Circuit Breaker
Your AC system typically has two breakers — one for the indoor air handler/furnace and one for the outdoor condenser unit. If either breaker has tripped, part of your system may be running while the other part isn't. Check your electrical panel and reset any tripped breakers.
Important: If a breaker trips repeatedly, do not keep resetting it. This indicates an electrical problem that needs professional diagnosis. Continuing to reset a tripping breaker can cause damage or create a safety hazard.
4. Check the Outdoor Unit
Go outside and look at your condenser unit. Is the fan running? If the indoor system is blowing air but the outdoor unit isn't running, the condenser may have lost power, the capacitor may have failed, or the compressor may have a problem. These require professional repair.
Also check for debris. Leaves, grass clippings, and overgrown vegetation can block airflow around the condenser. Clear at least 2 feet of space around the unit on all sides. If the coils are visibly dirty, you can gently rinse them with a garden hose (from the inside out) — but be careful not to bend the fins.
5. Check Your Vents and Registers
Walk through your home and make sure all supply vents and return registers are open and unobstructed. Furniture, rugs, curtains, and even closed doors can block airflow and create hot spots. Closing too many vents can also increase pressure in the duct system, reducing overall efficiency and potentially damaging the blower motor.
6. Look for Ice on the Indoor Unit
If you see ice forming on the refrigerant lines or the indoor evaporator coil, your AC has a problem. Common causes include a dirty filter (restricting airflow), low refrigerant (from a leak), or a failing blower motor.
What to do: Turn the system to FAN ONLY (or OFF) and let the ice melt completely. Check and replace the filter. If the system freezes again after restarting, you need professional service — the most likely cause is a refrigerant leak, which requires a licensed technician to diagnose and repair.
7. Consider the Age of Your System
Air conditioners typically last 10 to 15 years. If your system is in that range and struggling to cool your home, it may be losing capacity due to age-related wear. Compressor efficiency degrades over time, refrigerant leaks become more common, and electrical components fatigue. At some point, the cost of repeated repairs exceeds the value of the equipment.
If your AC is over 10 years old and you're facing a significant repair, ask your technician to compare the repair cost against the cost of a new system. At Siegman & Schaefer, we'll give you the honest math so you can make an informed decision.
When to Call a Professional
If you've checked all seven items above and your AC still isn't cooling properly, it's time to call a professional. Common issues that require a technician include:
- • Refrigerant leaks (requires EPA-certified technician)
- • Failed capacitor or compressor
- • Electrical problems
- • Frozen evaporator coil that keeps refreezing
- • Ductwork leaks or disconnections
- • Thermostat malfunction
Need AC repair now?
Siegman & Schaefer offers 24/7 emergency AC service in Hanover PA, Westminster MD, and surrounding communities.
Prevent AC problems before they start
Our Diamond maintenance plan includes spring AC inspections that catch small problems before they become expensive emergencies during peak summer heat.