DIY HVAC repair guides, industry news, product spotlights, and expert tips from the team at Open To Public HVAC Parts in Dallas, TX.
When your thermostat calls for cooling but the blower fan inside your home won’t turn on, a faulty fan relay is a common culprit. The relay is a small electrical switch that tells the blower motor when to run. When it fails, air stops moving through your ducts even though the rest of the system…
A failing AC capacitor can make your entire system seem like it’s on its last legs. The unit won’t start, the fan stutters, or you hear a humming sound from outside. Before you start pricing new air conditioners, it’s worth understanding what a capacitor actually does — and why replacing one small part might be…
You don’t need to be an electrician to do basic HVAC troubleshooting and repairs, but understanding a few wiring fundamentals will save you a lot of confusion — and potentially save you from making an expensive mistake. The Two Voltage Systems Your HVAC system runs on two completely different voltage levels, and understanding this is…
The inducer motor is the first thing that kicks on when your furnace starts a heating cycle. It’s a small blower that pulls air through the heat exchanger and vents combustion gases out through the flue pipe. If the inducer motor doesn’t run — or doesn’t run fast enough — your furnace will lock out…
If your AC is running but the air coming out of the vents isn’t cold, low refrigerant is one of the most common causes. Unlike a bad capacitor or contactor that you can swap out yourself, refrigerant work requires an EPA-certified technician. But knowing the signs helps you avoid getting overcharged for a misdiagnosis. The…
That gray metal box on the wall next to your outdoor AC unit is called the disconnect box, and it’s one of the most important safety devices in your HVAC system. Before you do any work on your air conditioner — even something as simple as cleaning the coils — you need to know how…
Your furnace has a built-in safety device called a pressure switch that verifies the inducer motor is pulling combustion gases out of the heat exchanger before the burners light. If the pressure switch doesn’t close, the furnace locks out and won’t fire — even though everything else seems fine. This is one of the most…
Your outdoor AC unit pulls air through aluminum fins to release heat from the refrigerant. Over time, those fins collect dirt, grass clippings, cottonwood fluff, and other debris that acts like a blanket — trapping heat inside the system and forcing your compressor to work overtime. A dirty condenser coil is one of the most…
Every time your thermostat calls for cooling, a small but critical part called the contactor closes a high-voltage circuit to power on your compressor and condenser fan. Think of it as a heavy-duty light switch controlled by your thermostat’s 24V signal. When a contactor fails, your AC either won’t turn on at all, or it…
If your HVAC system won’t turn on at all — no fan, no heat, no cooling — the problem might be a bad transformer. The transformer steps down your home’s 120V or 240V power to the 24V that runs the thermostat and control circuits. When it fails, everything downstream goes dead. The good news: testing…