Pressure washer problemos

[johnik]

Greetings all, i have been given a Wickes branded pressure washer, plug it in and it pulses for 1/2 a second or so then waits a couple of seconds and repeats itself (trigger not touched), i pull the trigger and it blasts away for a couple of seconds then stops and repeat, took off the filter in the water inlet, clean as a clean thing after a bath and it worked as it should for 30 seconds or so then back to it,s stop / go tricks....any ideas peeps ?

 

[Chris Snow]

You have a leak on the high pressure side. That's what causes the pulsing when not in use.

 

[johnik]

You have a leak on the high pressure side. That's what causes the pulsing when not in use.

nothing obvious from the outside, i take it it,s in the pumping part ?

 

[Chris Snow]

Does it pulse all the time even after it's clearly primed enough?
Even the tiniest drip will cause it.

Not continuing to pump with the trigger held is very unusual though.

I'd guess you need to rebuild the pressure switch bit.

 

[carbon]

i pull the trigger and it blasts away for a couple of seconds then stops and repeat

I'm not familiar with these machines but some have flow sensitive unloader valves that control the pressure. If a pressure washer with one has a restriction on the outlet i.e. bit of debris in the nozzle it will effectively drop the pressure as it can't sense enough flow. As the trigger is still being held open the process will repeat. If you can disconnect the nozzle or lance from the trigger then try it again it should keep a constant flow of water without stopping. If it still stops try with the trigger removed as sometimes debris can collect inside the trigger valve.

 

[johnik]

thanks for the reply, yup it pulses then when i pull the trigger it blasts away like a goodun for 10-15 secs then stops and starts again after a second or so or rest
it was a freebie so if i cant repair it for pennies it will go to the tip

 

[johnik]

I'm not familiar with these machines but some have flow sensitive unloader valves that control the pressure. If a pressure washer with one has a restriction on the outlet i.e. bit of debris in the nozzle it will effectively drop the pressure as it can't sense enough flow. As the trigger is still being held open the process will repeat. If you can disconnect the nozzle or lance from the trigger then try it again it should keep a constant flow of water without stopping. If it still stops try with the trigger removed as sometimes debris can collect inside the trigger valve.

with the power switched off and just using mains water, it squirts away no problem when the trigger is pulled

 

[carbon]

with the power switched off and just using mains water, it squirts away no problem when the trigger is pulled

But the water isn't being pushed by the pump either so I wouldn't expect it to pulse as the outlet is only at mains water pressure not the pressure the machine is designed to operate at

 

[johnik]

thanks peeps, ill have a look tommorow

 

[johnik]

update, i took it apart, seems the problem is inside the valve block, a sealed plastic unit so if anyone wants a generic Chinese pump and lance in the BS23 area, comeand take them before they go to the tip

 

[carbon]

Any pictures of the pump?

 

[johnik]

 

[johnik]

 

[johnik]

it,s 10 inches long and very heavy

 

[carbon]

Sorry I was meaning the part that’s faulty

 

[johnik]

 

[johnik]

dog for scale

 

[carbon]

Is that welded together? As before I expect it’s one valve held open

 

[johnik]

Is that welded together? As before I expect it’s one valve held open

yup, all welded and the round things welded in place as well, as it was a freebie i decided to bin it