Clearing an airlock in a macerator

[Hugh Jaleak]

Most pumped systems do when they discharge into a stack pipe. I have never seen sewage coming out of the top of a soil stack where a pumped system has been involved. That said where a pumped system discharges into a manhole ( inspection chamber ) whch has a lateral 100 mm pipe to the sewer some care has to be taken with the benching ( bottom of the chamber ) to reduce the amount of splashing that occurs.

No, but you're asking it to pump into a larger pipe, for it then to find its way back out and to the stack by gravity. Bear in mind what it is these things are pumping, and the size of the pipework involved. The Manufacturers instructions clearly state how the discharge pipework must be arranged, and any attempt to alter, deviate or ignore these instructions is promptly going to invalidate the warranty, at the very least.

Secondly, a poorly fitted lateral into a chamber, particularly from a WC, can cause fouling of the opposite benching, which is the reason care must be taken when laying drains to avoid this scenario if at all possible.

 

[Agile]

I have one which goes up 50mm and then down about 1500 mm to then run horizontally for about 4000 mm all in 32 mm.

That empties all in one burst of just 3-4 seconds.

I also have a basin/shower going into mine and there must be a non return valve on that entry as toilet water does not cause that to rise.

Makes me wonder if you have a basin inlet with a non return valve which is somehow now leaking???

Tony

 

[Steelmasons]

As per this
View attachment 98288

Effectively a soil stack pipe with the vent high enough to not allow sewer gas to enter the building. Or an AAV a foot or two above the end of the pipe from the Saniflow to avoid pumped sewage being blasted into the AAV. Arranging the end of the pipe to be pointing down the stack would ( should ) eliminate the risk of the AAV being contaminated ( and hence not closing )

The vertical pipe to be larger diameter than the pipe from the Sanislim

Stop it FFS.

 

[Steelmasons]

Most pumped systems do when they discharge into a stack pipe. I have never seen sewage coming out of the top of a soil stack where a pumped system has been involved. That said where a pumped system discharges into a manhole ( inspection chamber ) whch has a lateral 100 mm pipe to the sewer some care has to be taken with the benching ( bottom of the chamber ) to reduce the amount of splashing that occurs.

Fitted many "tumblers" over the years...."care taken with regard to benching"?????????
Stop it..barons bend/channel flaunching has fook all to do with the function of macerator discharge.
Have you actually fitted a macerator???or even seen one???
Pains me it really does..

 

[Steelmasons]

I have one which goes up 50mm and then down about 1500 mm to then run horizontally for about 4000 mm all in 32 mm.

That empties all in one burst of just 3-4 seconds.

I also have a basin/shower going into mine and there must be a non return valve on that entry as toilet water does not cause that to rise.

Makes me wonder if you have a basin inlet with a non return valve which is somehow now leaking???

Tony

NRV is installed to vertical pipework and fitted close to macerator.
"goes up 50mm"?????so two tight radius elbows straight off waste outlet?...fook me they must be tight to achieve 50mm vertical height before changing direction...
You guys kill me....Feeling a tad embarrassed myself regarding the carp you guys spout.

 

[Agile]

I don't need an NRV on the outlet as its all gravity downwards after the 50 mm upstand.

Been fitted for about 8 years and given no problem at all so far. But nothing wrong is ever put into it!

Tony

 

[Agile]

I did fit the supplied NRV on an upward pumping one and it leaked and caused unwanted pumping bursts every 20 minutes.

Had to find a better quality spring loaded 32 mm one and that solved the problem.

So much for the silly rubber flap one they supply!

 

[Steelmasons]

So you have a "gravity" macerator?
...Really????

 

[Rogeranerley]

Thanks Newboy. The unit was open/detached overnight before I made my reconnection mistake. I've just now removed the shower and wash basin traps, neither of which have AAV, but am still suffering the same noise. It sounds as though either water or air is gurgling into the unit.

 

[bernardgreen]

Have you actually fitted a macerator???or even seen one???

Yes Mono Mutrator 8, including pipe work up to the main sewer. Seen a few behind the pan macerators,. would never fit one.

 

[Steelmasons]

Yes Mono Mutrator 8, including pipe work up to the main sewer. Seen a few behind the pan macerators,. would never fit one.

BS......your explanation says it all.."pipework up to the main sewer"...so I guess you by-passed interceptor?...or...waste from macerator discharged into stack?...discharged into tumbler??...discharged directly into manhole????
Jeez..
"Seen a few behind the pan macerators".......

 

[Hugh Jaleak]

The Mutrators are a totally different kettle of fish to the Saniflos' and I'd go so far to say as there's absolutely no comparison. The Mutrator is a different concept entirely, used in a different application and therefore installed on a different basis. The previous advice on the Saniflo, at best could result in someone getting a shower of sh!t, at worst be downright dangerous.

 

[Newboy]

Thanks Newboy. The unit was open/detached overnight before I made my reconnection mistake. I've just now removed the shower and wash basin traps, neither of which have AAV, but am still suffering the same noise. It sounds as though either water or air is gurgling into the unit.

It's unlikely to be liquid running back into the unit (that would trigger then pump again) so it would suggest that there is some siphoning occurring. Might be worth removing the breather cap (temporarily) and see if there is any change.

Simply disconnecting the unit as you have described is unlikely to have created a problem assuming everything has operated correctly.

The only reason I can think of as a cause of the noise could be the backflow flap opening and closing as siphoning occurs - quite why that has suddenly started I can't imagine!

It's a dim memory but if I recall correctly, Saniflo do advise the use of an AAV on discharge pipework where there is a long gravity run - might be worth checking the MIs/recommendations

 

[Newboy]

Just checked the MI's - the symptoms you describe are covered and indicate that the air vent (under the breather cap & carbon filter) is clogged. It's a simple lever float on the underside of the lid and can be cleared by inserting a blunt thin object (screwdriver blade) gently into the vent hole. Power off first!

 

[bernardgreen]

BS......your explanation says it all.."pipework up to the main sewer"...so I guess you by-passed interceptor?...or...waste from macerator discharged into stack?...discharged into tumbler??...discharged directly into manhole????

While it is really non of your business I will say a bit

The plan was to take the plastic to a chamber inside our boundary and for a contractor to open the road and lay a 4 inch to a saddle the councl would fit on the top of the main sewer. All plans approved by the relevant authorities, When the council work crew arrived they immediately said. ""Cannot be done. The sewer there is cast iron and too close to the surface for a saddle to be fitted. "" Contractor opened up the road over the sewer and confirmed, metal sewer inches below the surface. ( the location was a few yards from where the road crossed a stream ). Building control and interested parties are called and they arrived at the site within the hour. It was admitted that the records about the sewer are wrong. After a short discussion it is agreed that our plastic pipe could be taken straight to an inspection chamber on the sewer about 5 metres from the planned location. The benching was to be altered to accept the new entry which would enter the chamber at invert level.

As luck would have it we had enough pipe to reach the inspection chamber and the work was completed that afternoon thanks to the willing co-operation of the officials and the work crew.