In short
Nothing happens when you press start: check the door switch, the breaker and any thermal cut-out before suspecting the motor, which is the least likely cause and the most expensive one to assume. These platforms decide almost everything in software, so a sensor that drifts rather than fails keeps the appliance behaving plausibly and wrongly. Nearly all of this is free to check and needs no tool at all.
What you actually see
- It starts only while the button is held — A start switch or a motor centrifugal switch that is not latching.
- A click from the door and then nothing — The door switch is being made and something downstream is refusing.
- No lights, no drum, no response — A supply fault or a door switch that is not made.
- NEAR MISS: it stops partway through a cycle — That is a cycle or overheat fault, not a start fault.
The causes in order of likelihood
- Door switch not confirming closed — Most likely here. It leads because the door switch is the first condition the machine checks and a mechanical latch can satisfy the door without satisfying the switch. The most common cause. The door can latch mechanically while its switch fails to make, and the machine simply refuses.
- Partial or missing supply — Next most likely. A dryer on a heavy circuit can lose one half of its supply and present as a machine that will not start at all, with everything else looking normal.
- Thermal cut-out or protector open — Third in the order. A protector that has opened because of restricted airflow stops the machine and stays open until it is reset or replaced.
- Broken drive belt — Then this one. The motor runs, the drum does not, and the machine hums. The most obvious symptom in this category and easy to recognise.
- Body: These are ordered for this brand and appliance rather than for the appliance class in general, and the ordering is qualitative.
The diagnostic order
- Open and close the door firmly and listen for the switch — A machine that starts on a firmer close has answered the question.
- Check the breaker, including both halves of a heavy circuit — A partial supply loss is the classic reason a dryer is entirely dead.
- Listen for a hum when start is pressed — A hum with no rotation moves the investigation to the belt.
- Body: The order below checks the machine start conditions before anything mechanical is suspected.
What you can do now
- Close the door deliberately and press start again — The single highest-yield check in this category.
- Reset the breaker once if it has tripped — If it trips again, stop and treat it as an electrical fault.
- Turn the drum by hand with the machine isolated — A drum that spins freely with no resistance suggests a broken belt.
- STOP before removing the back panel or testing a switch — That is a live circuit and a heated appliance.
Safety first
Safety
Unplug the appliance or switch off its breaker before removing any panel; a capacitor can hold a charge after the power is off. Never bypass a door switch or a thermal protector to make a dryer run: the protector opened because the machine was too hot, and defeating it is how a lint fire starts.
When this becomes a service call
Call when the door closes properly, the supply is proven at both halves of the circuit and the machine is still silent, or when it hums without turning. Call rather than investigate if the machine has been overheating, because a protector that has opened is a symptom of a venting problem that needs correcting. Mention any recent work in the room: taps, cables and hoses are the usual casualties.
Pages of the same class
What this page does not cover
This page is written for the appliance class rather than for one Blomberg family or model line. Where a family- or model-specific page exists for your unit it is the more specific answer and should be preferred over this one; the brand and appliance hub linked below routes to everything more specific that exists today.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
