The short answer
On a Marathon dryer, a drum that turns without heat is most often a blocked lint filter or exhaust duct rather than half the electrical supply missing on a dual-circuit machine. The airflow path and the blockages in it come first on a compact machine, because its exhaust run is short and every restriction in it counts double. All three checks below are owner work, and not one of them needs a part.
The symptoms, and the ones that mean something else
- The room gets hot and humid while it runs — Exhaust escaping into the room means the duct is disconnected or blocked.
- The clothes come out warm but still wet — Warm and wet is an airflow fault; cold and wet is a heating one.
- The cycle takes far longer than it used to — Gradual lengthening is a duct silting up rather than a part failing.
- NEAR MISS — it heats and dries but squeals — Noise with normal drying belongs on the noise page.
What goes wrong here, in order
- A blocked lint filter or exhaust duct — A dryer works by moving heated air through the load and out. A loaded filter or a duct packed with lint chokes that flow, so the drum holds heat, the safety thermostat cuts the heater, and the clothes come out damp and warm. It leads because it is the commonest cause by a wide margin, it is free to fix, and it is also the one that starts fires. The machines are chosen for tight spaces, so they are usually boxed in on at least two sides.
- An overloaded drum that cannot move air — Air has to pass through the load, not around it. Packed tight, the drum holds damp air against the clothes and the cycle ends with everything warm and still wet. It ranks here because halving the load is a free and decisive test.
- Half the electrical supply missing on a dual-circuit machine — Many electric dryers draw the motor from one leg of the supply and the heater from both. Lose one and the drum turns perfectly while the heater never comes on, which reads as a heater fault and is not. It is last because the supply is proven good.
The order to check in
- Clean the filter and check for airflow at the outside vent — A weak or absent flow outside is the whole answer, whatever the heater is doing. First, because it is the likeliest to end the job.
- Run a half load on a standard programme — If it dries, the load was the problem and nothing is broken. Second, once that is clean.
- Check both breaker positions for the dryer circuit — A single tripped leg gives a turning drum with no heat at all. Third, and by now the answer is usually in hand.
The steps, with tools and times
- Clean the filter, then disconnect and clear the exhaust duct — Do the whole run to the outside vent, including the flap. This is the one that matters most.
Tools: vacuum, brushAbout 45 min
- Halve the load and rerun a standard cycle — Air has to pass through the load, and a packed drum will not let it.
About 25 min
- Reset both breaker positions for the dryer circuit — Switch fully off and back on rather than nudging them.
About 15 min
- STOP — clear the airflow first, then book the visit — Replacing a heating part without clearing the duct simply destroys the new part too.
The part that is not optional
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Lint is the fire hazard in this appliance: a duct that has not been cleared is the single most dangerous thing about a dryer, and clearing it is free.
When to call a technician
Call when the duct is clear, the programme is right and the supply is proven, and the machine still tumbles cold — that is an element, a cut-out or a gas fault, and all three are behind a panel. Anything on a gas machine past the supply valve is a technician's job from the start. On this brand the brand has a real parts channel behind it, which makes a proper diagnosis worth the effort.
Where to go next
What is not on this page
This page is written for the appliance class, not for one Marathon model line. Where a family- or model-specific page exists it is the better answer and it is linked below — go there first if your model is named. Not here: element ratings, duct diameters, burner assemblies, or part numbers.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
