Usually the problem occurs upstairs. Somebody calls in August, says the AC hasn’t shut off all day, and the bedrooms are sitting at 80 while the thermostat’s set to 74.
Most folks in Plano assume the unit’s on its way out. Sometimes, sure. But I’ve lost count of how many of these turned out to be shoddy ductwork instead, which is good news for your wallet more often than not.
Start With the Equipment
Take a call I ran this summer, off Parker Road. Two-story home, upstairs wouldn’t cool. The homeowner had already paid somebody to swap the capacitor and the thermostat, and it was still running nonstop.
I didn’t head for the attic right away. A clogged filter, a dirty evaporator coil, or low refrigerant will cause the same symptoms, so I checked those first. All three checked out.
That’s the step people skip. If the equipment’s the problem and you pay for new ductwork anyway, you’re still hot (just with nicer ducts).
Then I went room to room. Downstairs vents were blowing cold. The register in the master bedroom upstairs was barely moving air, and what came out felt lukewarm.
What Was Going On in the Attic
So up I went. The supply run to that bedroom had slid clean off its collar, probably months earlier, and it’d been blowing 55-degree air into the insulation ever since. The upstairs thermostat never reached its setpoint, so the system never got a break.
Took about twenty minutes with a new draw band and some mastic. Room was cool by dinner.
What bugged me was the rest of the attic. That house, like a lot of Plano homes built in the ’90s and early 2000s, had flex duct that’s now past 20 years old. The jacket was brittle, and the tape on half the joints had dried out and let go. That’s what an attic that can hit 140 in August does to tape.
That’s how most shoddy ductwork actually fails. Slowly, a little leak at every connection.
What You Can Check Yourself
You don’t need a tech to get a rough read. Stand under the vent in the room that won’t cool, then one near the air handler. If the far one’s weaker or warmer, the problem’s somewhere in between.
If your attic’s easy to get into, a flashlight on the main trunk will sometimes turn up a run that’s sagging between straps or kinked around a truss. That kind of shoddy ductwork chokes airflow even with zero leaks. I pulled one out from under a box of Christmas decorations once, squashed nearly flat.
Returns are harder to judge and, honestly, worse when they leak, because they pull hot attic air straight back through the coil.
Just don’t go walking joists in July. I’ve seen the ceiling holes.
Patch It or Replace It
Back to that Parker Road house. I gave him the honest version: we could seal and re-strap the worst joints that afternoon and buy him a few summers, or he could redo all of it and stop chasing leaks. He went with the patch for now. Fair enough.
If the trunks are solid, a thermal imaging scan to find the bad spots plus some mastic goes a long way.
But when shoddy ductwork is brittle end to end, or it was routed badly from the start, you’re paying for patches every year. That’s when ductwork installation makes more sense. On a two-story it’s a day, maybe two, and the new runs get sized off a load calculation.
In Plano, that kind of work needs a mechanical permit pulled by a licensed contractor. Anybody offering to skip it is telling you something.
Don’t Wait Until Next August
Once it cools off, it’s tempting to let this ride till spring. Don’t. Shoddy ductwork loses heat all winter too, and every extra hour your system runs is wear you’re paying for. Call Total Air & Heat at (972) 881-0020 and we’ll find where your air’s going. We’re Not Comfortable Until You Are.
Questions We Get
Can shoddy ductwork really make my AC run all day?
Yep. If enough cold air leaks out or the airflow’s choked, the thermostat never reaches its setting and the system just keeps going. Low refrigerant can do the same thing, though. Have both looked at.
How do I tell if my ducts are leaking
Rooms that never catch up to the thermostat are the biggest giveaway, especially upstairs. Dust streaks around a vent are another. You might hear whistling near the air handler too. A thermal imaging scan will settle it.
Do I gotta replace all of it or just the bad parts?
Usually just the bad parts. If the main trunks are in decent shape, sealing and re-strapping the problem runs does the job. Once shoddy ductwork is brittle everywhere and patched in a dozen spots, new ductwork’s cheaper long term.
Is shoddy ductwork worse here cause of the heat
Yeah. A Plano attic can top 130 degrees in summer, so every leak is swapping your cold air for the hottest air on the property. A leak you’d shrug off somewhere mild shows up on your electric bill here.
Can I just tape it up myself?
On a seam you can reach safely, sure. Use UL 181 foil tape or mastic, not cloth duct tape, which falls apart in attic heat. Rerouting or replacing runs is a licensed-tech job, and in Plano that usually means a permit.
And if you haven’t changed the filter since spring, do that today. It won’t fix a loose duct, but it won’t hurt.
