macerator blow back

[kflood]

Hi I got a new toilet and shower last year down stairs we had to get a macerator for toilet only.
when you flush toilet ( one out of ten flushes approximately) force water to blow up out of the sink plug hole
somtimes hits the ceiling so it's has a bit of pressure behind it. I don't think it's toilet water
but it give me a fright everytime and is embarrassing if it happens to visitors.
My question is can I get a one way valve under my sink fitted?
or is there another way to sort it?

 

[rpm]

A non-return valve will cure your problem but the root cause will continue to shorten the life span of the macerator pump slightly.

Somewhere in the pipe run to the drains is a problem which needs to be addressed.

PS. Welcome to the forums.

 

[Stigster]

You could fit a waterless trap like the HepvO Hepvo Waterless Valve. The way the internals work it will act as a non-return valve on the basin waste.

If anyone can think of why this is a bad idea then please say so!

 

[rpm]

If anyone can think of why this is a bad idea then please say so!

Thought I had already done that.

 

[Stigster]

You are right, the waste from the macerator must be plumbed incorrectly into the same pipe run the basin uses I guess. It should have it's own pipe run, usually up and over to a boss on a stack I take it?

Bunging in a waterless trap to prevent discharge out the basin is a gash way to remedy the situation. I didn't have my plumbing hat on yesterday.

 

[rpm]

The main point to me was that it was ok for 1yr and the blow back to the basin indicates there is pressure in the pipe now that only shows around 1:10 flushes confused

Ideally using a macerator which the basin waste could be connected to will mean this can`t happen but you can join the two pipes as long as the swept T joins from above and is far enough away from the pump. I often have to fit the non-return but usually on a bath or shower waste but have never fitted one on a basin.