In almost every case the dryer isn’t leaking — the vent is condensing. A dryer exhausts very hot, very wet air. When that air travels through a duct running somewhere cold, the moisture turns back into liquid water on the inside of the duct and runs down toward the appliance. In an Alberta winter this is close to inevitable in a long, sagging or blocked run.
A conventional vented dryer has no water supply and no drain. There is nothing inside it that holds water. So when people find a puddle behind the dryer, the instinct is to assume the machine has failed — and it almost never has.
What has happened is simpler. Your dryer’s entire job is to take several litres of water out of your clothes and push it out of the house as vapour. If anything stops that vapour from getting outside while it is still warm, it turns back into water, and gravity brings it home.
This is where our climate is genuinely different from most of the country.
A dryer exhausts air at roughly 50 to 60 °C. During a cold snap, the duct carrying that air through an unheated attic, crawlspace or garage can be sitting at −30 °C. That is a swing of eighty to ninety degrees over a few metres of duct, and warm saturated air simply cannot hold its moisture across a drop like that. It condenses on the duct wall, beads up, and runs back downhill.
This is why the single most common version of this call we get is seasonal: everything is fine from April to October, and the water appears when the weather turns. If that pattern matches yours, you have your answer — it is condensation, not a fault in the machine.
If you have ice building up around your exterior vent, treat it as urgent rather than cosmetic. It forms when exhaust air arrives too slow and too cool — which means the run is already restricted. The ice then narrows the opening further, which slows the air more, which builds more ice. That loop can seal the vent completely and force the full moisture load of every load of laundry back into your house.
Don’t chip at it with a screwdriver or anything sharp; vent hoods and dampers are thin and easy to wreck. Clear the duct and the icing usually stops on its own.
We clear the full run, find the sag or the blockage causing it, and check that the exterior damper actually opens and closes. Flat-rate, no pressure.
Worth thirty seconds before you go further, because the two get confused constantly.
Washer water is cold, appears during or straight after a wash cycle, often smells faintly of detergent, and usually shows up at the front or under the machine near the hoses. Vent condensation is warm or lukewarm, appears during or after a dry cycle, and shows up behind or beneath the dryer.
The clean test: run a dry cycle with the washer completely idle. If water still turns up, the washer is not involved.
The puddle itself is the least of it. Wet lint is the real issue — it packs down into a dense mat far faster than dry lint does, so a duct that is condensing is also a duct that is clogging at speed. That combination, restricted airflow and packed lint in a hot duct, is the mechanism behind dryer fires.
Beyond that, water sitting inside a wall or ceiling cavity does slow structural damage nobody sees until there is staining or a soft spot, and all that indoor moisture has to go somewhere — which is why a dryer that leaks and a laundry room that feels humid are so often the same fault. If you are also seeing fine lint settling on surfaces, that is the same restricted run pushing air out through its joints.
Clearing the duct is the first and usually the sufficient step: get air moving fast enough that moisture leaves the house before it has time to cool. Alongside that, any sag holding standing water gets supported or replaced, the run gets shortened or straightened where that is practical, rigid metal duct beats flexible foil anywhere it can be used, and any section crossing unheated space should be insulated.
Our dryer vent cleaning covers the full run from the appliance to the exterior hood, including checking that the damper moves freely. It is $150 flat stand-alone, or $60 added to a furnace or duct cleaning on the same visit — which is the sensible pairing if you are due for both anyway.