gary77

iTrader: (1)

bought a presure washer today but after using it for a while the overflow started pouring from the eaves.

hose was attatched to the kitchen sink , any ideas why this is happening

JGlanzaV

iTrader: (3)

Does it stop with the washer disconnected?

gary77

iTrader: (1)

it stopped eventually when turned the tap off, started again when i started using it again . i didnt try disconnecting the washer only , do you mean disconnect the hose from the tap or disconnect from washer and leave tap running . i might try it today

Paben

iTrader: (5)

Hmm, that's odd. The kitchen tap is usually on mains supply whereas the overflow comes from the water tank, so the one ought not to interfere with the other. Unless you are creating backpressure in the mains system which is forcing water past a failing ballcock valve? Easy enough to check.

Osimabu

iTrader: (2)

If your kitchen sink tap is a mixer tap, chances are the cold mains water is forcing its way back into the hot system via the hot tap valve while the pressure washer isn't running. This will eventually raise the water level in your cold tank up to the overflow and it will come out.

David Lock

That makes sense except it is usually difficult to connect to the end of a mixer tap?

And won't the "hot" tap be off and prevent any backflow? Turn on hot water in bathroom to see if overflow dries up.

Perhaps pressure washer is connected the wrong way around

dl

gary77

iTrader: (1)

thanks for the replies

the kitchen sink is a mixer and i did have the hot on aswell ,so what your saying makes sense, next time i'll try it with just the cold and see what happens ,

Osimabu

iTrader: (2)

In that case, what I've described is exactly what happened. It's a standard method to get rid of air locks in a hot supply when the cold tank has been drained and the flow from the hot taps is poor or non-existant when the tank is re-filled.

gary77

iTrader: (1)

yep , i'll get the presure washer out next weekend and only use cold , i'll post the outcome

thanks again

Miniman

iTrader: (2)

My pressure washer suggested using one way valve on the water supply hose to stop the back pressure (and I do use one). Cost about a fiver from a garden centre.

Osimabu

iTrader: (2)

Unfortunately that wouldn't have worked for the OP as he had connected the mains cold supply to the tank fed hot supply in the spout of his tap.

One way valves on garden hoses are to comply with the Water Regulations to prevent possible contamination of the mains water supply by the water in the hose, or anything it comes into contact with.