Treadmill won't turn on

Written by Jamie Miller, Founder & EditorLast checked 18 September 2026

Check the safety key first. The magnetic clip that attaches to your clothing is also the switch that lets the machine start, and a treadmill with the key off is completely dead by design. It falls off, gets knocked off, and ends up down the side of the deck more often than anything on this page actually breaks.

In order

The safety key. Seat it firmly in its recess on the console. Some models need it pressed into a specific orientation before anything lights up.
The on/off switch. Usually near the power inlet at the front, low down, and easy to knock when moving the machine or vacuuming.
The socket. Plug a lamp or a phone charger into the same socket. If that is dead too, the problem is the socket and not the treadmill.
The consumer unit. Look for a tripped breaker or RCD. If it trips again as soon as the treadmill runs, stop and get an electrician.
The plug fuse. On a UK moulded plug this needs the plug replacing; on a rewireable plug the fuse is accessible. A fuse that blows a second time is telling you about a fault in the machine. Do not fit a higher-rated one.
The cable. Look along its whole length for crushing, cuts or scorching, especially where the machine sits on it or where it passes a folding mechanism.

Console lights but the belt does not move

That is a different fault and a better sign: power is reaching the machine. It usually points at the motor, the drive belt or the control board rather than the supply. Some machines also refuse to start if the incline is not at its home position, so try lowering the incline fully first.

Where to stop

Everything above is done with the machine unplugged or from outside it. Removing the motor cover or the console to test further puts you next to mains wiring, and a capacitor can hold a charge after the plug is out. If the checks above have not found it, it is an engineer's job.

What we have not established

We hold no data on how often each of these causes turns out to be the real one. The order above runs cheapest and safest first, which is not the same as most likely.How we review.