THE WORK ORDER

We received a call from a homeowner in the neighborhood of Fish Hawk, FL, reporting that their LG Electric Dryer, model DLEX3700W, kept flashing a “D80” error code and was taking far too long to dry laundry. The homeowner, a busy family of five, mentioned a persistent odor, clothes that felt damp even after two cycles, and the “Flow Sense” bar pulsing on the control panel. Problems like these aren’t uncommon throughout Fish Hawk, especially during the sticky summer months, and we’ve noticed an uptick in dryer vent complaints in nearby Bloomingdale and Lithia, too.

THE DIAGNOSIS

Upon arrival, Technician Mike followed our standard diagnostic checklist developed for LG’s Flow Sense system. The D80 error code specifically indicates an airflow restriction—80% or more—usually due to lint buildup or a vent blockage. These issues are especially prevalent in Florida homes where high humidity prompts heavier lint shedding and (for neighborhoods like Starling) builders often route vent ducts through attics, increasing the risk of condensation and sticky lint clogs.

First, we ran a test cycle to confirm the error. The “Flow Sense” bar flashed four LEDs and the prominent D80 warning, which means a restriction more severe than typical maintenance would solve. Our technician inspected the lint screen—moderately clogged but not enough to trigger this warning alone.

Next, we disconnected the vent hose from the back of the dryer. Using a Shop-Vac and a Dryer Lint Brush (specifically the Gardus LintEater 12-foot rotary brush), we probed both the dryer outlet and inside the wall. Pulling the front panel confirmed no interior lint-fire risk. The vent line coming from the laundry room to the outside wall was almost completely matted with sticky lint and, notably, some caked-on debris—probably caused by high humidity and a recent roof replacement in that part of Fish Hawk. Using a Milwaukee M12 inspection camera, we confirmed a near total blockage about 9 feet from the dryer: a congregation of lint fused with blown-in attic insulation and a small fragment of roofing material left from construction.

As a secondary check, we tested cycling temperatures at the exhaust, confirming the thermal cutoff was limiting the dryer’s high heat cycle as a safety precaution, causing the extended dry times. Multimeter readings at the terminal block and heater coil were within spec, and no other error codes presented. More on How to Properly Install Your Vent Duct here.

THE FIX

With the immediate cause identified, the next step was a thorough cleaning and safeguarding against future issues. We:

• • Cleared and vacuumed the entire vent run, using both brush and vacuum attachements with flexible rods to reach tough bends common in Fish Hawk’s two-story homes.

• • Checked the vent cap outside, where a combination of humidity and wind-driven leaves had partially blocked the damper. We replaced the basic plastic vent cap with a higher-quality Lambro 4″ Aluminum Vent Hood (which includes a bird guard and resists corrosion better in Florida’s climate).

• • Replaced the internal moisture sensor bar (LG part #6500EL3001A) inside the drum, as mineral residue from humid air buildup can reduce sensor accuracy and frequently triggers over-dry cycles or early shutoff.

• • Ran a vent test with the LG test cycle—now, no “Flow Sense” LEDs lit, and exhaust airflow measured at 15 MPH at the outlet (normal is 14–18).

Finally, we briefed the homeowner on quarterly vent cleanings—especially important in Fish Hawk and Lithia where heavy pollen and construction debris find their way into dryer vent runs. We left a branded magnet with our Brandon Appliance Pros number taped above the washer for easy reminders.

FAQ: LG DLEX3700W “D80” Error & Maintenance in Fish Hawk, FL

Q1: What does the D80/D90/D95 “Flow Sense” error on my LG DLEX3700W really mean?
A: The D80 (and related D90, D95) code means your dryer has detected a major airflow restriction. On this model, four “Flow Sense” LEDs plus D80 means 80% of designed airflow is blocked, usually by lint, crushed duct, or blockages outside. Continued operation in this state risks dangerously high temperatures. See the LG technical bulletin for more.

Q2: Can Florida’s humidity really cause this kind of problem so quickly?
A: Absolutely! In Fish Hawk, high moisture in the air—even with AC running—leads to damp lint that clings inside ducts and can solidify if combined with attic dust, insulation, and leaf debris. Add in periodic construction, and a vent blockage like this can develop in a year (or less), even with regular lint screen cleaning. If your laundry feels muggy or “musty,” suspect the vent.

Q3: What upgrades help prevent this error on LG and similar dryers?
A: First, use rigid or semi-rigid metal vent (never vinyl) to minimize lint snags. Upgrade your outside vent to aluminum with a bird/leaf guard. For larger families, install an in-line booster fan if your vent run exceeds 25 feet. Schedule professional vent cleaning at least yearly—a must in Fish Hawk and Bloomingdale.

CONCLUSION

This LG DLEX3700W in Fish Hawk had a classic “Florida failure.” Between humidity, attic-located vent runs, and a touch of construction debris, even well-maintained homes can experience “Flow Sense” shutdowns. Fortunately, with the right diagnostic tools and parts—plus some extra attention to vent upgrades—your dryer will start, run, and finish cycles efficiently, keeping your laundry (and household) safe. For more tips or to book a vent cleaning, check out Brandon Appliance Pros.