The short answer
A DV dryer that ends its cycle early or runs on forever is usually reporting an airflow or sensing problem rather than a timer fault. On this family the moisture sensor and the vent are what the control reads, so they come before the control in the order.
What you observe
- Timed cycles work, automatic cycles do not — Close to diagnostic: the sensing path is at fault and the heating path is fine.
- Clothes hot on the outside and damp inside — Restricted airflow: the machine is making heat it cannot carry away.
- The display counts down then adds time back — The control is retrying a step it cannot complete, usually because it cannot reach its target.
- Only heavy loads misbehave — Marginal airflow: a small load still dries, a heavy one never reaches the sensor threshold.
- NEAR MISS - no heat at all in any cycle — That is a heating fault and belongs on the heating page.
Causes, most likely first on DV
- Restricted vent or a blocked lint path — Ranked first on the DV family: this family depends on a clear path to move moisture out, and a partly blocked duct lengthens every automatic cycle before it fails one. Every model code in the table above shares the same airflow path, which is why this ranks first here and lower on the brand-generic page. What moves against the brand-generic order is lower down: load size and load sorting sits above thermistor or cycling thermostat drift here, because these models share one layout, so its weak point shows across the whole family.
- Moisture sensor bars dirty or coated — Second: softener residue builds an insulating film on the sensor bars, and a filmed sensor calls a wet load dry within minutes of the start.
- Load size and load sorting — Third: a very small or a very mixed load is more than automatic sensing can read on any machine of this type, and it costs nothing to rule out.
- Thermistor or cycling thermostat drift — Fourth: cycle length is set from temperature as well as moisture, so a sensor reading a few degrees off stretches or truncates the run with nothing else to show.
- Control board or timer failure — Last: last, because almost every cycle complaint on this family resolves to the vent or the sensor before the board is reached.
Check in this order, and why
- Run a timed cycle and see whether it dries — This single test splits sensing faults from heating and airflow faults.
- Compare the discharge at the outside vent with what it used to be — It isolates the duct without the machine ever having to run unducted.
- Dry one small mixed load and compare with a heavy one — A machine that manages small loads only is telling you airflow is marginal.
- Repeat with a normal mixed load — Do this last, because a very small load can fail a sensing cycle on a perfectly healthy machine.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Treat lint as the fire hazard it is: clear it out of the filter housing and the duct rather than pushing it further in, and run the machine only with its panels fitted and its duct connected to the outside.
When to call a technician
Call once the vent is proven clear and the sensor bars are clean but the cycle still ends wrong: what is left is a thermistor or the control, and reaching either means opening the cabinet on this family.
Other DV pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
