none return valve after outlet pump on newish washing machin

[thatbloke]

do newish machines have a none return valve after the pump that empties them?
is it possible if you drain a machine into the trap below a kitchen sink that water from the sink can fill the trap then flow down into the washing machine?

my machine has be refilling after its finished its cycle , not full but when it is just about to shut off a couple of centre meters of water flows back into the tub.

so i switched off the water supply to the machine (blue valve at back of machine) and tried to dry some clothes (washer dryer) and came back to find them sopping.

what do you think guys? is water travelling back from my sink into my machine? surely there should be some kind of valve to prevent this?

see my earlier post about this..

 

[rocks1]

Some have them on the pump some don't. Put a loop in the waste pipe up as high it can go and see what happens.

 

[thatbloke]

will do , thanks. i took the pipe from the tub to the pump off and took out two curtain rings and a lot of fluff , i then put my fingers into the tub from where the pipe fits and puled out quite a bit more fluff , i could feel it tangled around the heating elements.
would it be worth my while do you think to remove the pump and giving it a good clean?

 

[rocks1]

Can do while your there then you know it's clean.

 

[thatbloke]

well that didn't work. still a puddle of water in there.
when i am waiting for the door to unlock i can hear water trickling down the back of the machine into the tub then when the door unlocks the water stops but there is a puddle of water in the tub.

could this be an inlet valve not closing? the thing is it closes when the machine unlocks the door so i am assuming it closes when the machine turns the power to it off.

also on the drying cycle , even if the machine is empty before the cycle starts the machine finishes the cycle with a puddle of water and a very wet load of clothes.

what do you think? sticking valve or a bunged up sensor perhaps? if the machine was telling the valve to stay open surely the water would gush in instead of this trickle?

 

[rocks1]

You have a sticking inlet valve it's letting water in and not shutting off. Remove the inlet hose is there sand on the back of the valve.

 

[thatbloke]

there was some crud in there yes , there was a plastic mesh filter then a rubber washer , i have cleaned it all up but its still letting past.
i have three valves there , two send water to the detergent drawer and the third sends water down the back of the machine directly into the tub.
i think this is the one that is sticking as there doesn't seem to be water flowing through the drawer aperture.
is there any way to clear these valves out?
this is what is happening , this happens at the end of every cycle.

http://www.youtube.com/watch?v=4aQzyz2b7tc

you can hear the pump switching off then 'end' is displayed then i am just waiting for the door to unlock.

if its a valve not shutting down properly why doesnt the tub just fill up to the brim when the machine isnt in use? all i am getting is a small puddle.

 

[rocks1]

It's called a flushing valve it goes in the back of the drum to flush the fluff away from the filter at the back of the heater box ,swap the valves round to test that's it's faulty Reason why it don't fill up is cos it only comes on in short spurts not all the time about 10 times during the programe.

 

[thatbloke]

so why would by machine be telling it to come on just before the door unlocks?
sorry if thats a silly question , as you have probably gathered i know nothing about washing machines.

 

[thatbloke]

ok had another look , i took the hose from the drum to the solenoid valve off at the drum end then put the machine on a drain cycle.
straight away it started pumping water out through the drain as normal and this hose was squirting water almost immediately , id didn't stop until the machine stopped and the door unlocked.

now if these solenoids only open when there is a current passing through them then isnt the valve is doing what it should and the fault lies in the valve always being live?
or am i completely wrong?

 

[Leccy758]

Possible PCB fault. I have had 2 machines this year with faulty PCB's powering up the fill valves at the wrong times (one as soon as the machine was turned on at the mains)

 

[thatbloke]

i was thinking this also , would there be any sensors on the machine anywhere telling this valve to open and close?
is this also the condensing valve for the dryer?

 

[thatbloke]

right then ,result.
had an engineer come out and have a look as the machine was still under warranty , apparently its a valve that feeds the condenser in the dryer , this should only be on when the machine is drying.
anyhow , pcb fault , changed the selector and a sensor to eliminate both as probable causes and through a process of elimination ended up at the pcb. wont have the part until next week but the solenoid valve has been disconnected so at least we have a washing machine , just no dryer.
Thanks for all the advice guys , much appreciated.

now , why would a pcb fail? dry solder joint? damp? failed component? anyone care to comment?