Dish Washer filling with water randomly

[collinsc]

Hi

Our Dish Washer is filling with water randomly... and we dont know why.... here's what is happening....

We use it Monday to Thursday.... after each usage the Dish Washer does NOT have water in it.
When it comes to Monday it has water in it.

We use the Washing Machine every Friday and we have mused perhaps this is somehow related but really we have no idea.


Thanks

 

[robinbanks]

Does the water in the dishwasher smell of laundry detergent?

If the two appliances are plumbed into the same waste, and it is blocked slightly down stream, and there is no/damaged backflow valve on the dishwasher it’s conceivable that the washer pumping its waste water out could backfill the dishwasher

 

[gas112]

intermittent inlet valve passing

 

[Echo the husky]

Check the dishwasher waste pipe rises before dropping down to the drain connection or water can run back from washing machine/sink and into the dishwasher.

If the pipe is positioned properly the water inlet valve could be very slowly passing water. Not fast enough to notice during the week but builds up during the long period between Thursday and Monday.

 

[collinsc]

Yes - it does smell a bit of laundry detergent... which is why we thought there could be a connection here.

thank you all.

so how do i check this? or clear it.....

 

[Echo the husky]

There are plenty of diagrams on the internet, I stole this one:

Note how the top of the waste hose is positioned as high as possible.

 

[JohnD]

If you show us photos of your waste pipes and the hoses from the appliances, we will probably spot the error. You must show the height of all of them relative to the floor and the worktop.

The reason for the high loop in the hoses, going up to the underside of the worktop, is so that water cannot run downhill into the hose from the sink or other appliance.

If you have a pump pushing out water from an appliance, it must be able to run downhill into the waste faster than it is being pumped.

 

[collinsc]

thanks both - i will try and get some relevant photos later....

All the units are 'built-in' however... so im not sure if i can easily access without pulling out units (in which case i may as well get an expert to take a look).

 

[denso13]

All the units are 'built-in' however... so im not sure if i can easily access without pulling out units (in which case i may as well get an expert to take a look).

Photos below the sink, showing the connection to the sink waste is fine.

 

[collinsc]

Please see attached.

Thanks

 

[denso13]

The hose needs to go up, then down, you can get a hose extension if required.

 

[collinsc]

Amazing - thanks!