In message , harryagain
writes

"Rusty" wrote in message
.. .
Thanks for responses.
It is not lamb or other meat fats.
It is a congealed, greasy, thin, near white cement type consistency,
but greasy and sticky on the hands and arms. At its worst, the rods
with claw end break free solid, then semi-solid crap.
I keep the dishwasher topped up with salt which should soften the
water. Nasty, very hard Cambridge water.
There is no feed from a washing machine into this drain.
It has a reasonable fall, but does turn a corner, maybe 45 deg as soon
6 inch after it hits the drain pipe.
I'm not the only one. A colleague across town had similar, and so did
his neighbour. The neighbour apparantly paid DynoRod ~£250 to fix !
But mine seems worse than theirs.

I think I'll try the hot caustic soda every 6 months.

Thanks.

The problem with modern dishwashers is that they are designed to use a very
minimum of water.
Maybe not enough to flush away residues in this case.

I wonder if a liquid dishwasher detergent would help?

I'm intrigued as to what the deposit is as I've never noticed such a
thing. But maybe that's because the drain here has the sink feeding it
as well. Maybe it's something about he local water supply?

If a wash hand basin was also connected to the same drain it might help.

Most dishwasher detergents contain a softener.

snip

Maybe you should get a proper chemical ion exchange water softener.
But don't drink the water.


Dishwashers include a built in water softner
--
Chris French