Karcher 2500 PSI Pressure Washer

SOURCE: trouble with Karcher Pressure washer

Dear Pgarciax,
It is important that you must have mentioned the model number of your Karcher. Just the same I can surely say that your machine's fault lies in the "SPILL VALVE"
When the gun is open and pressure is being produced, the spill valve is in a relaxed position. Also it has at the bottom a valve, which when pressure is produced it is closed. If this does not close due to dirt or corrosion, the pessure goes down. Now when you close the gun,pressure forces the spill valve down to close the electrical system. Now if the "o" rings of the spill valve are damaged, the machine will start going on and off while in stand-by. So if you know how to locate the Spill Valve, all one has to do is change it with a new one.
In some Karcher machines there are 2 spill valves. One regulates pressure and the other one is for switching off the machine when the gun is closed.
Low pressure could also be due to faulty suction or delivery valves. Most probably the suction valves.
But when saying that there are short interruptions while in stand by, I stick to the fact that the spill valve needs renewing.
Regards,
MG.

SOURCE: karcher 2600 psi pressure washer wont stay running

Remove and clean the carburator. Sound line a stuck needle on the float. 

SOURCE: Electric Karcher pressure washer surging when turned on

Dear firenutt681,
One simple thing you can do, is to check for leaks. Check if hose at machine is leaking. Check gun if it is leaking. You can also check if water still comes out of lance nozzel. These leaks however so small, will cause the machine to surge.
Another reason is due to a faulty SPILL VALVE. This spill valve( often called CONTROL VALVE) will contract when the gun is closed. When it contracts under the enclosed pressure it will switch off the machine by means of a Micro Switch. Now if this Spill valve is faulty it will loose its compression under pressure and puts on the micro switch again. This can be seen once in a while or more frequent, as in your case. I sometimes do service Spill Valves, but mostly I replace them with a new one. I do not know the model number of your machine, but normally you have to open the cover and you should spot the spill valve on the head. Most probably you see a thick wire or a cap containing the micro swith. If you find the micro switch, you have found the spill valve. Sometimes it is a bit hard to pull out the spill valve. Myself, in various Karcher models I remove the spill valve by trying to feed water and put on a bit the machine. In this way the spill valve will be spitted out.
Another reason which makes your machine surge, is leakage from from the detergent inlet.
If you do not see no leakages at all....then for sure it is the SPILL VALVE.
If you cannot do this job yourself or you do not find spare parts...you can continue using the machine as it is...but before closing the gun...switch off the electricity. I only recommend this in an emergency. You do this so that you do not leave the machine surging. This surge will for sure damage the electric motor and the capacitor (assuming it is single phase).
Regards,
Fulltech.

SOURCE: I have a 3000 psi karcher pressure washer with

sounds like you need a seal and bladder rebuild < if you liver in a cold environmet for winters please dont forget to winterize your washres every year before winter

SOURCE: I don't get a constant

Make sure that while you are running your pressure washer, other machines that pull

large volumes of water like a dishwasher or washing machine are not running. check and make sure

the hose you have tied to the pressure washer is not collapsing or has any kinks in it.

check the filter where your water hose ties in to your pressure washer, make sure it

is clean and does not have any debris or hardwater buildup, clean the tip at the tip of

the wand. if it is reduced in size by hardwater buildup, will not work properly, good luck!