Work down whichever list applies. Both are in order of likelihood, and most items need no parts and no tools.
Electric machines
1. The breaker or the plug’s own GFCI has tripped
Most electric pressure washers have a GFCI module built into the plug, with a reset button. Press it. Then check the household breaker.
If it trips again immediately, stop and do not keep resetting it — that is a fault, not a nuisance trip. If it trips only under load, you are probably sharing a circuit.
2. The thermal cutout has engaged
Electric motors have a thermal cutout that shuts them down when hot and resets once cooled. If the machine ran for a while, stopped and will not restart, this is likely.
Unplug it and leave it half an hour. Then address the cause: a long thin extension cord, a shared circuit, or leaving it idling with the trigger closed on a machine without total-stop.
3. An extension cord is dropping voltage
A long thin cord starves the motor, which makes it run hot and trip. Plug directly into a dedicated 15-amp outlet, or use a short heavy-gauge cord. If you need reach, use a longer hose.
4. It is “not starting” but actually has total-stop
A total-stop system means the pump only runs while the trigger is held. If you switch on and nothing happens, that may be correct behavior. Squeeze the trigger — if the motor starts, there is nothing wrong.
5. The pump is seized from freeze damage
If it was stored over winter without being winterized, the pump may have cracked or seized. Symptoms: a hum with no movement, a tripping breaker, or visible water weeping from the pump body. This is usually terminal, and it is what winterizing prevents.
Gas machines
1. Stale fuel
The number one cause by a wide margin, especially in spring. Untreated petrol degrades over months and will not fire.
Drain the tank and the carburettor bowl, refill with fresh fuel, and try again. Prevent it with stabilizer or by running the tank dry before storage.
2. The fuel valve, the choke or the throttle
In that order. Fuel valve open. Choke closed for a cold start and opened as it warms. Throttle in the run position. Obvious, and genuinely the cause often enough to check before anything else.
3. Low engine oil
Many engines have a low-oil cutout that prevents starting. Check the level on a level surface. Also check it is not over-filled, which causes its own problems.
4. The spark plug
Pull it and look. Wet means it is flooded — dry it, open the choke and try again. Black and fouled means it needs cleaning or replacing. White and clean with no spark means an ignition problem.
5. The air filter is clogged
A filter full of dust starves the engine of air. Pull it out and look; clean or replace.
6. A seized pump stopping the engine turning
If the recoil will barely move, the pump may be seized — usually freeze damage. The engine is fine; the pump is the problem.
Both: things that are not actually starting faults
It starts but has no pressure. Different problem — won’t build pressure.
It starts and stops immediately. On an electric, the thermal cutout or a supply problem. On gas, fuel starvation — often a partially blocked fuel line or vent.
It will not start after winter. Stale fuel on gas, freeze damage on either. Both preventable, and both are why the autumn checklist exists.
