In short
A dryer that ends early is usually measuring the load rather than failing: a moisture sensor reading dry, or a cut-out opening on heat. On this machine the first suspect is restricted vent making the machine cut out. Try a timed cycle instead of an automatic one — that one test splits the list in half.
What you observe
- The cycle ends after a few minutes with the load still wet — The sensor believes the load is dry, or a cut-out has opened.
- It stops part-way through and will not restart until it cools — A thermal cut-out, which points straight at the lint path.
- An automatic cycle ends early but a timed cycle works — The moisture sensing, not the heat or the airflow.
- NEAR MISS — it never starts at all — That is a start failure and the wont-start page ranks it.
Causes, most likely first on a Smad dryer
- Restricted vent making the machine cut out — It also stops the load ever reaching dry, so automatic cycles run on indefinitely. Ranked first on a Smad dryer: it is the one cause here that is also the fire risk in the appliance.
- Moisture sensor bars fooled by residue — The machine then reads dry within a few minutes and ends the cycle.
- A drum too full to tumble — A packed drum cannot move the load past the sensor, so the machine reads whatever happens to be touching it.
- Cycling thermostat or thermal cut-out — A one-shot thermal fuse ends the cycle permanently until it is replaced.
Check in this order, and why
- Disconnect the duct at the machine and run a short cycle — Check the outside flap opens while the machine runs.
- Try the same load on a timed cycle — Look for two metal strips inside the drum and check they are clean.
- Try the same programme with a half load — Look at whether the damp is in the middle of the load.
What an owner can safely check
- Clean the lint filter, pull the machine out and clear the duct and the outside flap along the whole run — Lint is the fuel in a dryer fire. Clear it before diagnosing anything electrical.
Tools: duct brush, vacuumAbout 45 min
- Wipe the moisture sensor bars inside the drum with a cloth and a little rubbing alcohol or vinegar — Softener residue insulates them. Clean bars read the load correctly again.
Tools: cloth, rubbing alcohol or vinegarAbout 15 min
- STOP HERE if the next step needs a panel off, a meter on live terminals, or the gas train — That is where the owner checks end; gas and high-current work are never owner work.
Before you open anything
Safety
Switch the dryer off at its breaker before opening anything; a capacitor can hold a charge after the power is down, and the circuit behind a dryer is a heavy one. Lint is what burns in a dryer, so the filter is cleaned every load and the duct is cleared regularly. On a gas machine, if you smell gas: do not switch anything on or off, leave the building, and call the gas utility or 911 from outside.
When to call a technician
Call once the sensor bars, the lint path, the load size and the door have all been dealt with and the cycle still misbehaves, because what is left is a thermostat, a thermal fuse or the control. Clear the duct first regardless of the cause. If your unit is an absorption model running on gas, the gas side is not owner work: a licensed gas technician handles the burner, the flue and any smell of gas.
Nearest pages of this class
What this page does not cover
This is the generalised Smad dryer page. A family- or model-specific page, where one exists, is linked above and is the more precise answer for your unit. Left out on purpose: part numbers, connector colours, the order panels come off in, and every torque figure — a generalised page cannot be right about any of them.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
