Why does my vacuum suddenly not turn on?

Most often the thermal cutoff tripped from a clogged airflow path. Let it cool 30 minutes and try again. If it trips repeatedly, the airflow path is still clogged.

Can I replace a vacuum switch myself?

On older mechanical switches with screws, often yes. On modern PCB-driven switches with soldered connections, bring it in.

Is a dead PCB worth repairing?

Depends on age. On a 3-year-old Miele worth fixing. On an 8-year-old Shark, usually not.

Diagnose

Your Vacuum Won't Turn On: 6 Things to Check

When a vacuum will not turn on the cause is one of six things in this order: dead outlet, broken cord, failed switch, thermal cutoff tripped, bag-full lockout engaged, or PCB failure. The first three are 5-minute home checks.

Causes, ordered by likelihood

Dead outlet. Easiest miss. Test the outlet with another device first.
Broken cord. Inspect the cord especially at the strain reliefs. A cut or crushed cord stops the vacuum and is a shock risk.
Failed on/off switch. Switches wear out around year 8 to 12 on most vacuums.
Thermal cutoff tripped. Overheating from a clogged airflow path trips the thermal cutoff. It resets when cool; if it trips repeatedly, address the clog.
Bag-full lockout (Miele). Some Miele models will not start if the bag is full or the bag holder is misaligned. Reseat the bag.
PCB failure. On newer cordless and PCB-driven vacuums, the controller board is the last suspect.

What to check at home

Test the outlet with another small appliance.
Inspect the cord end to end, especially at strain reliefs and any visible kinks.
If the vacuum has run hot recently, let it cool 30 minutes and try again. Thermal cutoffs reset.
On Miele, reseat the bag and confirm the indicator is not in lockout.
If all four pass, the switch or PCB is next. Bring it to the shop.

When to bring it in

Bring it in if outlet, cord, and reset all check out. Switch replacement runs $40 to $80. PCB replacement on cordless or modern Miele runs $120 to $260.

Call (703) 931-6100 Walk in to the shop

Brand-specific notes

Miele: Modern Miele canisters have a soft-touch power switch on the handle that can fail at year 10 to 12. Switch replacement is a bench job.
Dyson: V-series Dyson that won't turn on is usually a battery state-of-charge issue, not a power switch issue. Check the battery LED first.
Shark: Shark uprights often have a foot pedal switch that fails. Bench replacement runs about $40 to $80.

Common questions

Why does my vacuum suddenly not turn on?: Most often the thermal cutoff tripped from a clogged airflow path. Let it cool 30 minutes and try again. If it trips repeatedly, the airflow path is still clogged.
Can I replace a vacuum switch myself?: On older mechanical switches with screws, often yes. On modern PCB-driven switches with soldered connections, bring it in.
Is a dead PCB worth repairing?: Depends on age. On a 3-year-old Miele worth fixing. On an 8-year-old Shark, usually not.