You release the trigger and the motor stops, which is exactly how a Total Stop machine should behave.
Then, with nobody touching anything, the motor kicks back in for a second. It stops again, then restarts, sometimes every few seconds and sometimes every few minutes.
Most people assume the switch has failed. In most cases the switch works fine, and the fault sits somewhere else.
How Total Stop actually works
On a Total Stop machine, the motor only runs while you need water. Our guide to Kränzle model names covers which models have it.
When you release the trigger, pressure builds in the line between the pump and the gun. A pressure switch senses that rise and turns the motor off.
When you pull the trigger again, the pressure drops and the switch starts the motor. It is a simple loop, and it works reliably until something allows pressure to escape.
That is the whole diagnosis in one sentence. If the motor restarts with the trigger closed, pressure is leaking out of the system faster than it should.
The switch sees the drop and does its job. So the task is to find the leak, not to replace the switch.
Rule out the obvious first
Before you strip anything, spend two minutes on the simple causes.
Check that the lance sits fully home in the gun and the nozzle is the right size. A lance that is not locked in can weep at the coupling and bleed pressure away.
Look at the detergent setting as well. On some setups, an open chemical valve lets the system draw air, and that upsets the pressure in the line.
If the machine also struggles to reach full pressure when you spray, read our pressure diagnosis guide first. A weak pump and a cycling pump often share the same cause.
Start at the gun
The trigger gun is the most common culprit, and it is also the easiest part to check.
Inside the gun, a small valve seals whenever you release the trigger. Grit, limescale and general wear all prevent it seating.
Look at the nozzle with the trigger released. A steady drip or a thin weep from the lance means the gun valve is passing water. Even a slow drip lets enough pressure go to trip the switch.
Check the quick release coupling where the lance meets the gun. A worn O-ring there leaks under pressure and often looks wet after a few minutes.
The repair typically means a seal kit or a replacement gun rather than anything inside the machine. Both are cheap compared with the time you lose to a machine that keeps cycling.
Then follow the hose
If the gun stays dry, move back along the high pressure hose and look at every joint.
Run your hand along each fitting with the machine pressurised. Wet fingers point you to the leak faster than your eyes will.
Look carefully at the hose ends, where the metal crimp meets the rubber. That is where hoses deteriorate first, and a weep there is a safety issue as well as a cycling fault.
A hose reel adds another seal at the swivel joint. Reels leak there more often than people expect, especially on machines that get dragged around a yard.
Our range of Kränzle hoses covers replacements and reels. Never tape a weeping hose, because it is a high pressure component and it can fail without warning.
Check the outlet and the pump head
Once the gun and hose check out, the leak sits somewhere on the machine itself.
Look at the outlet fitting and the pressure gauge. Both use threaded joints that vibration can loosen over time.
Then look underneath the pump head. A drip or a damp patch where the head meets the crankcase points to worn water seals.
Worn seals let pressure bleed back past the plungers when the motor stops. The switch then sees the pressure fall and restarts the motor.
You may also see milky oil in the sight glass, which confirms water is getting past the seals. That is a workshop job, and it is better done now than after the bearings suffer.
The non-return valve and the unloader
If nothing outside is wet, the leak is usually internal, which makes it harder to spot without a gauge.
Total Stop machines rely on a non-return valve to hold pressure in the line. If that valve wears or catches debris, pressure leaks back towards the pump and the motor cycles.
The unloader valve can cause similar symptoms when its seals wear. It may also make the machine hunt, with the pressure rising and falling while you spray.
A quick test helps narrow it down. Close the trigger, watch the gauge and time how long the pressure takes to fall. A fast fall with no visible leak points inside the machine.
These parts need the right seal kits and a pressure test afterwards. We hold Kränzle service spare parts in stock, so most of these repairs do not wait on an order.
Air in the system can fool you
Sometimes nothing is leaking at all, and the machine is simply full of air.
Air compresses where water does not, so a pocket of air in the pump or hose makes the pressure bounce. The switch can react to that movement.
Purge the air before you go looking for faults. With the motor off, turn the water on and squeeze the trigger until a steady stream runs with no spitting.
Air usually gets in through a poor water supply. Loose inlet fittings, split supply hoses and taps that cannot keep up all draw air into the pump.
Our guide to getting the water supply right explains what a pump needs to stay fed. A starved pump also wears its valves faster, which leads straight back to cycling.
When the switch really is the fault
It does happen, although far less frequently than most operators think.
A failed pressure switch may stop the motor at the wrong pressure, or fail to stop it at all. It can also stick, so the motor will not restart when you pull the trigger.
Electrical supply problems can look similar. A weak supply or a long, thin extension lead makes the motor struggle to restart. It may also trip the breaker.
Check the supply before you blame the switch. Our guide to electrical supply covers the right sockets and cable sizes.
Switch faults need a multimeter and a proper test. Guessing wastes money on parts you did not need.
Why it matters if you leave it
A machine that cycles every few seconds is not just annoying. Every restart puts load on the motor, the switch contacts and the starting components.
Over a long working day, that adds up to thousands of additional starts the motor was never designed to make. Small leaks also grow, and seals that weep today fail completely later.
Catching it early usually means a seal kit. Leaving it often means a seal kit, a replacement switch and a tired motor.
Frequently asked questions
Why does my pressure washer keep turning on and off?
On a Total Stop machine, the motor restarts when pressure drops in the line. If it cycles with the trigger closed, pressure is leaking somewhere. The usual suspects are the gun, a hose fitting or the pump seals.
Is it the pressure switch?
Usually not, because the switch typically reacts correctly to a genuine pressure leak. Check the gun, hose and fittings for leaks before you replace the switch.
Can I keep using a machine that cycles?
You can for a short time, but the extra starts wear the motor and switch. Find and fix the leak as soon as you can.
How much does a Kränzle service cost?
A full workshop service costs £169 including VAT on a cold water machine. A hot water machine with descale costs £279. Our £39 inspection fee comes off the bill if you go ahead with the work.
Do you stock the seal kits?
Yes. We stock seal kits, valves and pump parts for the Kränzle range. Most repairs go ahead without waiting for an order.
The bottom line
A machine that switches itself on is almost always losing pressure, not losing its mind.
Start at the gun, follow the hose, check the pump head, then look inside. Purge the air and check the supply before you blame the switch.
Small leaks are cheap to fix and big ones are not. Do not leave it running like that for weeks.
Bring it to our Bedfordshire workshop for a full service with a written report. Every repair carries a twelve month warranty on our workmanship.
Send us the model number and tell us how often it cycles. We will point you to the likely fault before you spend anything.