Bosch pressure washer spitting the hose off.

Jun 11, 2016 Last reply: 7 years ago 31 Replies

Hello all.



Just bought a Bosch pressure washer to replace the 20 year old Wickes one that finally bit the dust.



The hose pipe has the "safety" connection that closes when there's nothing connected. I switch the machine on and all well, until I release the trigger, when the hose connector pops off the machine.



Anyone know if this is normal? Or should I take it back? Or just change the hose fitting?


I'm a bit confused. Every pressure washer I have seen has had a threaded connector between the pressure hose and the machine. What you are describing sounds like a feature of some hozelock couplings which are only rated for domestic water (about 3 bar).

Take it back.

My Nilfisk specifically recommended not using the "waterstop" type hose connector onto the pressure washer ...

I presumed he was talking about the mains inlet to the P/W ...

I imagine that's just because of potential flow restriction, I can't see it affecting the connector "grip".

To the OP, I'd just try a different hosepipe fitting, preferably without the waterstop feature.

Tim

They don't have a particularly high flow rate.

I imagine it's the rapid shut off (solenoid valve?) of the P/W when releasing the trigger that causes the inlet to blow off.

Will try that, thanks. Can't find one right now, and shops all shut until Monday.

If your mains pressure isn't great an auto stop valve on the end may be just the straw that breaks the camel's back.

Well yes, but please share your theory as to why an auto-stop hose connector blows off more easily than a standard one.

Tim

With a standard connector, the sudden back pressure when turning off can be absorbed by the full length of the hose pipe.

With a waterstop connector the back-pressure is all between the valve inside the pressure washer and the hose connector, probably on rigid pipework, so is exerted directly onto the connector ...

As it can with an waterstop.

Wrong. A waterstop valve only occluded the pipe when it is physically disconnected.

As long as it is connected, there is continuity.

Tim

Fair enough, I thought it acted as a form of non-return valve too.

Mine has a hozelock connector. Male part)

Try changing the hozelock bit on your hosepipe before taking it back. The female bit most commonly goes wrong.

They use a pressure switch rather than a solenoid.

The problem with the waterstop is a spring loaded N/R valve. Since the pump sucks it forces the valve shut & stops the flow.

Easy enough to convert it. Take it apart & remove the disc & spring.

I don't think so Dave, The Water Stop is held open by the male part pushing it off the seal face.

The OP probably just has a worn out or imitation Hoselock fitting. I had some Aldo ones once that were not very good when used with a proper hoselock although okay with each other.

Sorry Dave, but as I've explained, this is exactly what a waterstop valve

*isn't*.

My waterstop valves are neither spring loaded or non-return.

In normal use water flow will try to close the valve but if the hose is connected to a male connector the male part holds the valve open. It cannot close in this circumstance, even if suction is applied. It will introduce some flow restriction though compared to a non-waterstop valve which is I think the main reason for not using one with a pressure washer.

Tim

But that sounds a bit counter intuitive as in effect its sucking at that point so how can this produce the opposite effect one wonders unless its faulty. Brian

I swapped it for another which works just fine.

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