Many LG dryers have a feature called Flow Sense. It watches how well air is moving out through the exhaust and warns you before a restriction becomes a real problem. When it detects trouble, the display shows a code such as d75, d80, d90 or d95, and on many models a Flow Sense light comes on as well.
These are some of the most common codes we see on LG dryers in Calgary, and most of the time the fix starts outside the dryer rather than inside it. This guide explains what each number means, a special note on d80 for gas models, the safe checks you can do, and when it makes sense to call for help.
What the d codes mean
LG's d75, d80, d90 and d95 codes all mean the same thing: exhaust airflow is restricted. The number tells you roughly what percentage of the airflow is blocked, so the higher it goes, the more urgent it is.
| Code | Roughly blocked | What to do |
|---|---|---|
| d75 | About 75% | Clean filter and check duct soon |
| d80 | About 80% | Check duct and hood; on gas models, check gas |
| d90 | About 90% | Clean the vent run before regular use |
| d95 | About 95% | Stop using heat until the vent is cleared |
On many models the dryer still runs with the code showing, but drying times get longer and the dryer runs hotter. The usual causes are a lint-clogged vent or a crushed or kinked duct.
Why the code may show on only some loads
Flow Sense measures conditions during each cycle, so a partly blocked vent may trigger a code on a big load of towels but not on a small load of shirts. A code that comes and goes is still a warning. The restriction is there; it is just close to the limit.
d80 on gas models
On gas LG dryers, d80 can also mean the dryer is not getting gas. Without a flame, the air never heats properly, and the sensor reads the result as poor flow. If you have a gas dryer showing d80 and the air in the drum is cold, check two things without touching any fittings:
- The gas shut-off valve behind the dryer should be open, with the handle in line with the pipe.
- The flexible gas connector should not be kinked or crushed against the wall.
Do not loosen fittings or open any gas parts. Some LG gas models show a separate gAS code, which means the dryer is not receiving gas, for the same causes. If the valve is open and the line is clear, the problem is likely the igniter or gas valve; see our post on a gas igniter that glows but won't light and our gas dryer repair service. If you smell gas at any point, leave the house and call ATCO Gas emergency at 1-800-511-3447 from outside.
Safe checks before you call
Unplug the dryer before moving it or touching the duct. Then work through these steps in order.
- Clean the lint filter. LG filters can trap a film from dryer sheets. Wash the filter in warm soapy water, rinse and let it dry fully.
- Check the filter housing. Shine a light into the slot and vacuum out any lint that has slipped past the filter.
- Check the transition duct behind the dryer. It should be smooth and not squashed against the wall. Replace foil or vinyl duct with semi-rigid metal.
- Check the outside hood. Lint, snow, ice or a bird's nest can block the flap. With the dryer running, the flap should open and you should feel strong airflow.
- Test without the duct. With the dryer unplugged, detach the duct from the back, then plug in and run a short air-only cycle. If the code clears, the restriction is in your vent, not the dryer.
Vent length and layout
Long runs with many elbows, common with upstairs laundry rooms and roof vents, can trigger d codes even when clean. Every bend adds resistance. If your dryer has shown d codes since the day it was installed, the vent layout itself may be the issue, and shortening the run or reducing elbows can help.
Cold weather and frost
In an Alberta winter, warm, damp exhaust freezes on the hood and flap, and frost can build up inside the last part of the duct. That is a very common cause of d codes in January and February. Our post on winter dryer vents and frost explains how to clear the hood safely. Never use a heat gun or open flame.
Other LG codes that appear with d codes
A restricted vent often triggers more than one warning. These codes from LG's list tend to show up around the same time:
- tE2: a thermistor error, usually in cold conditions, such as a cold or iced exhaust duct, steam cycles, or a failed thermistor.
- F0 or Insert Filter: the lint filter is not inserted properly. Check it is fully seated after cleaning.
- nP: no current detected at the heater, usually a tripped breaker leg or an outlet problem. Our post on the LG nP code covers it.
- gAS: the gas dryer is not receiving gas, from a closed valve or kinked gas line.
Our LG dryer codes section lists the rest, and the all-brand error code page covers other makes.
Why you should not ignore Flow Sense
It is tempting to clear the code and keep drying, especially when the dryer still seems to work. But a restricted vent makes every load take longer, raises the temperature inside the cabinet, wears out heating parts and the thermal fuse, and lets lint collect where it can catch fire. Flow Sense is an early warning, and it is most useful when you act on it.
There is also a cost in time and energy. A dryer pushing against a 90% restriction may need two full cycles for a load that should take one, and the extra heat is hard on elastic, synthetics and printed fabrics. Over months, the blower wheel can pack with lint and the thermal fuse can blow, which turns a simple vent cleaning into a parts repair. When we clean a vent after a long run of d codes, we usually check the blower housing and the thermistor too, because both can be affected by prolonged high exhaust temperatures.
If the code keeps returning, have the full vent run cleaned. Our dryer vent cleaning schedule explains how often that should happen, and a professional dryer vent cleaning reaches the parts of the duct you cannot.
When to call a technician
Book a visit if the d code stays after you have cleaned the filter and checked the duct and hood, if the vent run is too long or too high to reach, or if a gas model shows d80 with no heat. We can clean the full vent, check the blower and Flow Sense readings, and test the heating system to make sure nothing was damaged by running hot.
Fast Appliance Repair serves Calgary, Airdrie, Cochrane and nearby towns. Call (587) 779-6919 for same-day service when available. You pay a flat diagnostic fee, get a full quote before any work, and every repair includes a 90-day parts and labour warranty.