Lavac Popular Toilet Installation

[Pete735]

I fitted a new Lavac Popular toilet today, complete with new pump, pipes and ball valves - boat out of water. I expected to pump it with inlet ball valve closed (outlet open) and get a healthy vacuum that lasted a minute or so. The seat vacuum only lasts a few seconds - does this sound correct?
I had to change the toilet base position to get output pipe in accessible position, so I took unit out and removed base again and then resealed it - thinking seal there was faulty. Still not much vacuum. I've retightened all jubilee clips. Tomorrow I plan to disconnect input pipe and put it in a bucket of water and try a "flush" as a test.
I also removed input to pump and loads of vacuum at pump entry. Am beginning to wonder if sanitation grade pipe I bought is porous! Am I expecting too much or is this typical? If it pumps water ok, then can I assume all is well? Both seat seals look fine.

Thanks for any comments

 

[VicS]

I would not expect it to hold a vacuum for long in the dry state. In normal operation the vacuum takes while to fall but not minutes. The vacuum drops partly because water is being drawn in from the inlet and mainly because air is entering via the air bleed.
I would not expect the pump valves to hold a vacuum for very long and the air bleed will collapse it within 20 seconds perhaps any way.

Try it again with some water you should be able to create a fairly good vacuum with the inlet valve shut. If you put your finger on the air bleed it should then hold the vacuum for quite a while if every thing is OK.

 

[Searush]

A good bit of detritus will help the vacuum! Seriously tho', as Vic says, they don't hold the vacuum for that long, although it can seem inordinately long if you are desperate to use it immediately after another has been & you can't get the lid up!

The valves are simply rubber flaps, they, and the rubber seat seals, will definitely work better with a bit of water on them.

 

[Clyde_Wanderer]

Also you can adjust the height of the two plastic seat/lid hinge posts, up or down, to ensure that the seat/lid seals are mating with the top surface of the pan all the way round.
I had noticed on mine that the seat/lid was sitting slightly higher at the back causing it to lose some vacuam, adjusted it down slightly and all was fine.

 

[peterb]

Make sure that the hinge holes are slightly loose. When the vacuum is applied the whole seat should move down, to compress the seal uniformly. If there is no slack in the hinge then the back of the seat stays high and you will get a poor seal.

 

[Bajansailor]

With our Lavac I find that we dont get a very good seal after putting the lid down - the rubber must be getting a bit perished (its about 14 years old now).
But it does form an excellent seal if I sit on the lid (when it is down) and then pump.

 

[VicS]

[ QUOTE ]
if you are desperate to use it immediately after another has been & you can't get the lid up!

[/ QUOTE ] Probably time you cleaned the air bleed then!

 

[sailorman]

undo the retaining fixings & back-off the lock nuts.
flush the loo & whilst the loo is under vacuum, tighten the top nuts to just touch the porcelain then tighen the lower nuts the seat should now be aligned with the pan.
our basin waste uses the loo via a diverter valve so we can break the seal at will its very useful

 

[Pete735]

Thanks for all the comments, sounds like I may be worrying about nothing.

I will, however, take a careful look at the seat/lid pivot assembly in case that is misaligned or sticking.

Once again many thanks.

 

[jerryat]

[ QUOTE ]
undo the retaining fixings & back-off the lock nuts.
flush the loo & whilst the loo is under vacuum, tighten the top nuts to just touch the porcelain then tighen the lower nuts the seat should now be aligned with the pan.
our basin waste uses the loo via a diverter valve so we can break the seal at will its very useful

[/ QUOTE ]

Yep, that is definitely the best way to do it, though oddly it doesn't say anything about this in the otherwise comprehensive installation instructions.

As other have said, the whole seat/lid assembly has to be able to pull down evenly and it's why the hinge holes through the seat and lid are so large.

 

[samwise]

With a brand new Lavac, the seals sometimes need a bit of assistance i.e. hand pressure on the lid, to seat properly for the first few flushes. As they bed in, it should achieve the seal without help. Lavac advise that the vacuum should last about 30 seconds.

 

[Pete735]

Had a fun time with this today. I removed inlet and put pipe into a bucket of water and was able to pump - absolutely nothing! I sat on seat and pumped - not easy with pump above my right shoulder, still nothing. Finally, I was able to suck some water into toilet by jiggling the pipe input fitting that goes into the back of the loo, but no sooner had I managed this than I found I was unable to repeat it. All the hissing noises came from this area as well, so I think it's a call to the manufacturers tomorrow,

Looks like a 1/2 inch plastic bsp fitting coming out of loo with a male thread on it and screwed onto that is a female threaded elbow that inlet sanitation hose fits to. Only way to tighten this fitting - assuming it's not sealing - is to jam something down centre of pipe - probably one of those pipe fitting that have a couple of internal dimples at 180 degrees and you hold it by these. Trouble is to do that the complete assembly has to come out as it's pretty well up against the bulkhead. Hence a call to BLT before I go any further, unless anyone on the forum has any futher thoughts?

 

[VicS]

It does rather sound like a leak around the inlet connection.

I would have put some water in the loo and pumped that out just to prove that the pump is pumping OK and then also looked for any signs of leaks at the ends of the hose between toilet and pump.

I reminds me that when a friend installed a new one we had difficulties getting a good joint between the inlet hose and its fitting. We wound some insualtion tape on the spigot then fitted the hose (Just as a temporary measure you understand .... but its still like it 15 years or more later!). He was using the old hoses, though.

No elbow on his either so things are a bit different. I wonder were these bits just supplied loosely fitted together with the intention that you fitted what you needed to use properly.

I'd take the whole thing out again and have a good look at that inlet. Determine what's wrong and if something is defective get onto BLT.