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.
AC Clicking But Not Starting
Hearing clicking from the outdoor unit? Learn why the AC won’t start and which part likely needs replacement.
AC Fan Not Spinning
The outdoor fan blade won’t turn. Find out if it’s the capacitor, motor, fan blade, or contactor.
Furnace Not Heating
Gas furnace producing no heat? Troubleshoot the ignitor, flame sensor, gas valve, and more.
Furnace Short Cycling
Furnace turns on and off repeatedly. Learn what causes short cycling and how to stop it.
Thermostat Not Working
Thermostat won’t control your system? Check the thermostat, transformer, fuse, or control board.
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 →How-To Replacement Guides
How to Replace an AC Capacitor
Step-by-step DIY guide with photos, wiring diagram, and safety tips. Replace your capacitor in 15 minutes and save $200+.
How to Replace an AC Contactor
Step-by-step DIY guide with wiring diagrams, testing instructions, and safety tips. Replace your contactor in 20 minutes and save $250+.
Read Guide →How to Replace a Condenser Fan Motor
Complete DIY guide with wiring diagrams for OEM and universal motors. Replace your condenser fan motor in 30–45 minutes and save $400+.
Read Guide →How to Replace a Blower Motor
Complete DIY guide covering removal, installation, wiring (3-speed and 4-speed), belly band and Rheem bracket mounts. Save $400+ on repairs.
Read Guide →How to Replace an Ignitor & Clean a Flame Sensor
Complete DIY guide for furnace ignitors and flame sensors. Covers diagnosis, multimeter testing, cleaning, and step-by-step replacement. Save $200–$400.
Read Guide →How to Replace a Heat Sequencer
Complete DIY guide for electric furnace heat sequencers. Covers diagnosis, terminal testing, wiring, and step-by-step replacement. Save $200–$350.
Read Guide →How to Replace a Gas Valve
Complete DIY guide for furnace gas valve replacement. Covers diagnosis, gas line safety, wiring, and step-by-step procedures. Save $300–$500.
Read Guide →How to Replace an HVAC Control Board
Complete DIY guide for furnace and air handler control boards. Covers diagnostic LED codes, fuse testing, wiring, and step-by-step replacement. Save $200–$450.
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