HVAC Troubleshooting Guides

🛠️

Diagnose and fix common heating and cooling problems

At Open To Public HVAC Parts, we believe homeowners and technicians should understand how their heating and cooling systems work. Our troubleshooting guides walk you through diagnosing common problems like an experienced technician would — with diagnostic tips, product images from our catalog, and links to find the right replacement parts.

We’ve served the Dallas HVAC community since 1998. Whether you’re a DIY homeowner or a professional tech, we’re here to help you get the job done.

Select Your Problem

❄️

AC Not Cooling

Your AC runs but isn’t producing cold air. Diagnose capacitor, contactor, fan motor, and thermostat issues.

Read Guide →

⚡

AC Clicking But Not Starting

Hearing clicking from the outdoor unit? Learn why the AC won’t start and which part likely needs replacement.

Read Guide →

🌀

AC Fan Not Spinning

The outdoor fan blade won’t turn. Find out if it’s the capacitor, motor, fan blade, or contactor.

Read Guide →

🔥

Furnace Not Heating

Gas furnace producing no heat? Troubleshoot the ignitor, flame sensor, gas valve, and more.

Read Guide →

🔄

Furnace Short Cycling

Furnace turns on and off repeatedly. Learn what causes short cycling and how to stop it.

Read Guide →

🌡️

Thermostat Not Working

Thermostat won’t control your system? Check the thermostat, transformer, fuse, or control board.

Read Guide →

❄️

AC Freezing Up

Ice on your AC lines or coil? Diagnose dirty filters, blower motor issues, and low refrigerant causes.

Read Guide →
🔥

Furnace Blowing Cold Air

Furnace runs but no heat? Troubleshoot the flame sensor, ignitor, gas valve, and limit switch.

Read Guide →
💨

No Airflow — Blower Not Working

No air coming from vents? Check the blower capacitor, motor, relay, and control board.

Read Guide →
💧

AC Leaking Water Inside

Water pooling around your indoor unit? Diagnose clogged drains, frozen coils, and failed condensate pumps.

Read Guide →

Can’t Find Your Problem?

Our expert staff can help you diagnose your issue and find the right parts. Bring your old part in and we’ll test it for free.

📞 (214) 340-9421

Mon–Fri 10 am – 7 pm | Sat 10 am – 3 pm

Visit Open To Public HVAC Parts in Dallas

Address: 10226 Plano Rd #104, Dallas, TX 75238

Phone: (214) 340-9421

Hours: Mon–Fri 10 am – 7 pm | Sat 10 am – 3 pm

We stock parts for Rheem, Lennox, Trane, York, Carrier, Goodman, and more.

HVAC Capacitor Cross-Reference Chart

Need to find an equivalent capacitor from a different brand? Our comprehensive cross-reference chart compares part numbers across 9 major manufacturers.

View Cross-Reference Chart

Common Troubleshooting Questions

How do I know which part is causing the problem?
Start with the symptoms. AC not cooling? Check the capacitor and contactor first. No heat? Check the ignitor and flame sensor. Each guide above walks you through the most likely parts to check based on what your system is doing. You can also call us at (214) 340-9421 and describe what’s happening.
Can I test a part myself before buying a replacement?
Some parts you can test at home with a multimeter (like capacitors and contactors). For others, bring the part to our store and we’ll bench-test it for free at the counter. No purchase necessary — we’ll tell you if it’s bad before you spend a dime.
Is it safe to do my own HVAC repair?
Most common repairs like replacing a capacitor, contactor, ignitor, or flame sensor are straightforward and safe if you turn off power to the unit first. Always shut off the breaker and verify power is off with a multimeter before touching anything. If it involves refrigerant, gas lines, or electrical wiring you’re not comfortable with, call a pro.
What if I replace a part and it still doesn’t work?
Sometimes more than one part fails at the same time, especially after a power surge. Bring the old part and the new part to our store — we’ll test both and help you figure out what else to check. Our counter staff troubleshoots these situations every day.

See all frequently asked questions