Start here
A cabinet that will not start is a supply-side fault far more often than a mechanical one. Confirm the outlet is live and that the appliance is actually receiving it, then look at the start relay, and treat the compressor as the last suspect rather than the first. Do these in order and you will either fix it or hand a technician a much shorter problem. Work down the list rather than across it.
Symptoms and near misses
- A click every few minutes, then silence — The start relay is trying, the compressor is not taking, and the overload opens again.
- A short buzz at the back and nothing else — The compressor is being asked to start and is stalling against pressure or a bad winding.
- No interior light, no display, no hum — The cabinet is completely inert when you open the door.
- NEAR MISS: it runs constantly and is simply not cold — That is a cooling fault, not a start fault, and it is a different page.
What is usually behind it, in order
- No usable power at the outlet or the cord — The one to suspect first. It leads here because adaptive control will not call for cooling until it trusts its inputs, and a supply interruption resets that trust. A tripped breaker, a failed outlet, a damaged cord-set or a switched socket someone turned off. It is the most common single reason a cabinet is dark and it is free to rule out.
- Main control board not calling for cooling — The second suspect. The board decides whether the compressor runs at all, and one that has lost its output leaves everything else looking healthy.
- Thermistor or thermostat reading the cabinet as already cold — Third, and less common. If the control believes the box is at setpoint it will never call for cooling, and the symptom is a machine that does nothing rather than one that runs badly.
- Start relay or capacitor failure — Fourth, and less common again. The relay drops the start winding in and out.
- Body: These are ordered for this brand and appliance rather than for the appliance class in general, and the ordering is qualitative.
Check in this order, and why
- Try the outlet with something you know works — A lamp or a phone charger settles the supply question in seconds and rules out the single most common cause.
- Open the door and watch the interior light — Light with no running means control power is fine and the fault is downstream; no light at all sends you back to the supply.
- Listen at the back for a click on a repeating cycle — A regular click with no start is the start relay signature and it separates relay from board without any tool.
- Body: The order below moves from free checks to paid ones and stops before anything that needs a meter on live terminals.
Step by step, safely
- Plug something else into the same outlet — If it does not work either, the fault is the outlet or the breaker and not the appliance.
- Reseat the plug and inspect the cord where it enters the cabinet — Look for crushing behind the unit and for heat discolouration at the plug.
Tools: torch
- Take the appliance off any extension lead or power strip — Run it direct from a wall outlet for an hour and see whether it starts.
- STOP if the next step means testing a relay or a winding — That is a meter on live terminals and it is where the owner-side work ends.
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. The start relay and compressor terminals stay dangerous after the cabinet goes quiet.
Where owner work ends
Call once the outlet is proven good and the cabinet still does nothing, and call immediately if the plug or cord shows heat damage, if the breaker trips, or if the compressor hums and never starts. Sealed-system work is licensed work. A diagnosis reached by elimination is worth acting on; one reached by guessing is not.
Nearby pages
What is out of scope
This page is written for the appliance class rather than for one Bosch 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.
