A typical load should be dry in about 40 to 60 minutes. If yours needs a second run every time, something is slowing the dryer down. It is tempting to blame an old machine, but in most homes the dryer itself is fine. The real problem is the path the air takes to get outside. A restricted vent makes every load take longer, costs more to run, and raises the temperature inside the cabinet.
This guide explains why venting matters so much, the vent problems we find most often, the other causes worth ruling out, and the checks you can safely do yourself before booking a visit.
Why venting matters so much
Your dryer pushes hot, wet air out through the duct to a hood on the outside wall or roof. It can only dry as fast as it can get rid of that moisture. When the vent is partly blocked, damp air lingers in the drum and the clothes simply stay wet longer. At the same time, heat builds up, which can trip safety limits and wear out parts like the thermal fuse. If yours keeps failing, see why a dryer thermal fuse keeps blowing.
Think of it like breathing through a straw. The dryer still works, but every load is a struggle, and the struggle shows up as time, energy and wear.
The three most common vent problems
Lint build-up in the duct
The lint screen catches most lint, but not all of it. Over months and years, fine lint coats the inside of the duct and narrows it. Bends and low spots collect the most. Lint is also very flammable, so this is a safety issue as well as an efficiency one. Our post on how often to clean a dryer vent covers a sensible schedule.
Long or twisty vent runs
Every metre of duct and every elbow adds resistance. Manufacturers list a maximum vent length for each model, and each 90-degree bend counts as a few extra metres. Many homes, particularly newer builds and townhouses, have runs that are close to or over the limit. The dryer may still work, but it never works well, and it is extra sensitive to even a small amount of lint.
Upstairs and interior laundry rooms
Second-floor laundry is popular in newer Calgary neighbourhoods, but it often means a long duct running through a ceiling or wall to the roof. Lint can settle in long horizontal sections, and roof vents can trap lint behind a flap. In winter, moist air can freeze at the outlet and narrow it further. Our article on winter dryer vents, frost and lint explains what to watch for.
Other causes worth ruling out
If the vent turns out to be clear, the slow drying is coming from somewhere else. This table sums up the usual suspects.
| Symptom | Likely cause | Who fixes it |
|---|---|---|
| Weak airflow at the outside hood | Lint in duct or crushed hose | DIY check, then vent cleaning |
| Air in the drum only warm | Element, igniter or thermostat | Technician |
| Sensor cycle ends early, clothes damp | Coated moisture sensor bars | DIY clean |
| Centre of the load still wet | Overloaded drum | DIY: smaller loads |
| Clothes soaking from the washer | Poor washer spin | Washer repair |
| Long-dry or cycle-time code | Restricted vent or heating fault | DIY check, then technician |
Weak heat
If the air in the drum feels only warm, a heating element, a gas igniter or a thermostat may be failing. On electric dryers, a tripped leg of the double breaker can cut the heat completely while the drum keeps turning. If the heat has dropped off rather than the airflow, our dryer not heating repair page explains what we test.
Sensor bars and load size
On sensor-dry cycles, a film of fabric softener or dryer-sheet residue on the metal bars inside the drum fools the dryer into thinking the load is dry, so it stops early. Wiping the bars with rubbing alcohol on a soft cloth usually solves it. Overloading has a similar effect: a packed drum leaves the centre of the load wet. Our guide to clothes still damp after a cycle goes through each of these.
Codes that point to long drying
Some dryers flag slow drying for you. Frigidaire's E4A means drying took longer than the program time. Electrolux EF3 means the maximum cycle time was exceeded, and on some Asko models F2 means the maximum drying time was reached. In each case a restricted vent is the first thing to check.
What a slow dryer is really costing you
Running every load twice feels like a minor annoyance, but it adds up in three ways.
- Energy. The heater or burner is the biggest power user in the laundry room. Doubling the run time roughly doubles what each load costs to dry, every week of the year.
- Wear. Longer cycles mean more hours on the motor, belt, drum rollers and heating parts. Components that should last a decade start failing early.
- Heat and fire risk. A dryer that cannot breathe runs hotter. Lint near the heater or burner sees more heat for longer, and the safety limits work harder. Our guide to dryer fire safety and lint explains why that matters.
Clothes suffer too. Long, hot cycles shrink cotton, fade colours and break down elastic in a way a normal 50-minute cycle does not.
Safe checks before you call
Always unplug the dryer before moving it or touching the duct. On gas dryers, do not disconnect or bend the gas line.
- Feel the outside airflow. Plug back in, run the dryer on high heat and go outside. You should feel a strong, steady stream at the hood. A weak puff means a restriction.
- Check the hood flap. Make sure it opens freely and is not blocked by lint, snow, ice or a nest.
- Inspect the transition duct behind the dryer for kinks or crushing. Replace flimsy foil or plastic ducting with semi-rigid or rigid metal.
- Compare inside and outside. With the dryer unplugged, detach the duct from the back of the dryer, then run it briefly with the duct off. If the air coming out of the dryer is strong but the outside flow was weak, the problem is in the vent, not the dryer.
- Time a towel load. If drying time drops a lot after cleaning, you have found the cause.
Stacked and closet installs
Stacked units and dryers in tight closets often have the hardest vent runs. The transition duct gets squashed when the unit is pushed back, and there is little room to inspect it. If you cannot reach the connection safely, leave it for a technician. Our stacked dryer repair service handles these installs, including pulling the unit out and refitting the duct properly.
When to call a technician
If the vent run is long, goes through the roof, or still feels weak after you clean what you can reach, book a professional dryer vent cleaning. If the vent is clear and the dryer is still slow, the heating system and sensors need testing. Fast Appliance Repair covers Airdrie, Cochrane, Chestermere and the surrounding towns, with same-day visits when the schedule allows. You pay a flat diagnostic fee, get a full quote before any work, and every repair is covered by our 90-day parts and labour warranty. To book, call (587) 779-6919.