My drain is in danger of not clearing properly - Help!!

[Mc1000]

Fellow members - Please bear with me whilst I try to explain.

I have a 9m lateral drain (I suspect with insufficient fall-angle) to handle all waste, inc sinks, washer, shower, toilet etc from a garden flat.

Because we are below street level this drain issues into a sump/ manhole in the garden which houses a float switch pump unit that periodically activates when part-full to pump all the content up to street level and the main sewer system.

So far so good, it works ok.

EXCEPT that periodically it starts to back up as a result I think of insufficient water and gravity to fully clear the drain to the sump.

This could be due to a combination of insufficient water quantity from the loo (macerator) and or shallow fall of soil pipe when first laid (probably by a dodgy builder!). The trouble is that this pipe is now deep under the concrete floor of the flat and the thought of digging it out and relaying, plus all the making good (its a stone tiled floor) is close to unthinkable.

Anyone got any suggestions for how to get more evacuation to the sump? Extra strong macerator with more water-whoosh for example or some sort of suction device?

All suggestions, no matter how crazy, are welcomed!!! Thank you in advance,​

 

[rpm]

What are you currently doing when it does start to back up?
Because you say it periodically backs up then it is possible that the sump / pit needs cleaning out with a hosepipe and a broom because the float of the pump in the pit is sticking in either the off postion or the run postion in which case the motor could be overheating and stopping for awhile.

Re the macerator, if you flush the toilet does the water enter the pit via it`s own discharge pipe or has it been Tee`d in to the main pipe under the floor (remove pit cover and look whilst toilet is flushed) and sometimes flushing the toilet when not used is a good idea if the discharge pipe is incorrectly installed. To end I can`t think of a suction device that will be of use in this instance but please come back and tell us what you found and welcome to the forum.

 

[snowhead]

I'd agree with above, I'd suspect the pump and or float failing or set too high first.

There should be enough "wooosh" from a washing machine, bath shower etc to clear.

Next thought would be to have a camera scan to see if there is a collapse or tree root breakthrough.

Over 9mtrs it shouldn't be too difficult to calculate the fall.