new external drain all blocked up

[ivixor]

The trouble is that that trap is too large for the volume of water going through it. So there is never enough velocity to sweep the solids from the disposal around the bend.

If there is only that kitchen waste going in there I would put the u-bend inside in 40mm like this: https://www.village-bakery.com/wp-c...erator-Garbage-Disposals-for-your-Kitchen.jpg . Then change the outside connection to a straight connection with a sealed top with one of these: https://www.plastics-express.co.uk/image/cache/data/Without Watermark/SP420-250x250.jpg

The smaller size will ensure that debris is swept round and down by the water flow.

 

[Ian H]

I’m not sure that’s right.

In a commercial kitchen there would be an internal or external grease trap to catch the solids before the enter the drain.

I would say you need a grease trap or scrape all food into the bin.

https://www.greasetrapsukonline.co....sqmv7u4hqdaydyrvfr5dhdhmwem1ad98aapxqealw_wcb

 

[ivixor]

Nope. In sink disposals are common and the whole point is that the solids go down the drain. They are not some experimental newfangled invention.

 

[Ian H]

Maybe he isn’t using it right then, solids need water or they won’t travel down a drain.

 

[Hugh Jaleak]

That gulley should be going to a combined sewer, it must be trapped for the rainwater connection.

The whole idea of a waste disposal unit is the solids are minced up, and the resulting debris is washed down the drain. Not come across one yet though that hasn't caused problems with the discharge pipework at some point, and with the increasing abuse of the drainage system, water companies are increasing education about what can and cant go down the drain.

 

[pr1970ster]

Thanks for the replies.
I`ve found someone whos going to come and cement it all in and put in the drain properly as he`s doing some roof repairs anyway.

With the waste disposal, i think part of the issue was what we were putting in some bad food waste. My wife was on a new diet that had lots of boiled eggs so the shell was going down. Cereals waste from my sons muesli that he never finishes, potato peelings,etc. Basically all the things that i`ve now read you shouldnt put down there.
Part of the reason for getting one in the first place was i was sick of having to put out the food waste for collection, have enough with plastics, paper,metal,etc. Felt like i spent half week going outside to the bins emptying stuff out from the kitchen.
cheers