Lavac toilets

[mansell]

Can anyone help ?

Have a Lavac toilet with a new large Jabsco diaphragm pump. All tubes according to Lavac manual. Evacutes well. Seal on seat and lid appear good.

But it will not draw water in after evacuation even when sitting on the lid. Vacuum holds for not more than 5 seconds. Valve with the small hole is in the top of the loop. Discovered from Lavac that when they fitted a timer it was set for 30 to 40 seconds. Tried keeping the pump pumping for 45 seconds, but still no good.

Would welcome ideas.

Regards

Chris

 

[chasroberts]

Tape over the hole and try pumping. Don't worry you won't screw it up but it might take a while for the vacuum to break. If all is flushing OK then the hole/valve is too large to allow enough of a vacuum to build to lift the water from the intake to the bowl.

When I replaced the inlet pipe the last time I made a hole at the top of the gooseneck with a 1.5mm drillbit and forgot about the valve altogether. Water won't flow out because of the pressure difference when you pump. This has been fine for 3 years now. You can always make the hole bigger if it won't release in a suitable time period but do it by very slow increments until you reach a good compromise.

Good luck and happy pumping....

Chas

 

[sailorman]

Can anyone help ?

Have a Lavac toilet with a new large Jabsco diaphragm pump. All tubes according to Lavac manual. Evacutes well. Seal on seat and lid appear good.

But it will not draw water in after evacuation even when sitting on the lid. Vacuum holds for not more than 5 seconds. Valve with the small hole is in the top of the loop. Discovered from Lavac that when they fitted a timer it was set for 30 to 40 seconds. Tried keeping the pump pumping for 45 seconds, but still no good.

Would welcome ideas.

Regards

Chris

Henderson pump is the correct pump
is the lid cracked ?
i guess the hole is too big in the loop
get a Bic pen remove the top end cap & try that or perhaps a bit o gaffer tape over the hole & make a smaller hole.

 

[Tranona]

The "valve" is actually a plug out of the end of a ball point pen. So replace with one of those and try again. If you don't get a vacuum then the seals may need replacing.

 

[capnsensible]

Have lived aboard with one of these for 15 years.

Generally when that happens, the pump is caked up and the non return valve is not shutting.

I carry a spare pump ready to use and a service kit. Out old, on new, heads back in use, clean at leisure. In fact there has been times when I just went and got a new spare pump and binned the clogged one. 15 years of the same tends to do that!!!

Hope this helps CS

 

[VicS]

Have a Lavac toilet with a new large Jabsco diaphragm pump.

Discovered from Lavac that when they fitted a timer it was set for 30 to 40 seconds. Tried keeping the pump pumping for 45 seconds, but still no good.

Do I deduce that you have an electric pump.

If so is it a suitable pump.

I thought electric Lavacs used an electrically operated version of the normal Henderson Bilge pump ( keeping the manual pump in series for when the electrics fail)

If pump is all suitable and OK then I agree try taping over the hole and making a smaller one ... as an experiment before replacing the insert with one with a smaller hole

Initially stick you finger over the hole and see if you can get it to create a good enough vauum to draw in water. If still no vacuum look for air leaks and double check pump

Lavac Instructions manual

 

[Dave_Seager]

Lavac electric toilets have been supplied with a Jabsco pump for several years but they have still not updated their web site. I do not think that the Henderson pump is available any more.

Also, Lavac no longer supply an automatic timer. I found that it was impractical to just have a push-button switch for the pump as one has to press it for about a minute for a full flush. I built and fitted two timers for mine, to give a choice of a long or short flush.

They usually supply two alternative plugs to go in the inlet pipe. These simply provide an air bleed hole and do not have a valve. Two sizes are provided to allow you to choose whichever suits your particular installation better. The purpose of the bleed is not just to release the vacuum after flushing but also ensures that a greater volume of material can be pumped out than clean water pumped in.

 

[Babylon]

I do not think that the Henderson pump is available any more.

Are you sure about this? I purchased fitted a new Henderson MkV eighteen months ago, a white version of this one:

http://www.force4.co.uk/807/Henderson---Whale-Mark-5-Bilge-Pump.html

 

[Storyline]

Are you sure the seals on the lid and seat are on correctly ?

 

[VicS]

Are you sure about this? I purchased fitted a new Henderson MkV eighteen months ago, a white version of this one:

http://www.force4.co.uk/807/Henderson---Whale-Mark-5-Bilge-Pump.html

They seem to be Mark V Whale pumps now but that's the manual one.

There are electrically operated Jabsco (and similar Whale) diaphragm pumps which are presumably what are supplied now in place of an an electrified version of the MKV Henderson/Whale. They have lower quoted pumping rates than the manual MkV although of course the throughput of a manual pump rather depends upon how fast you operate it.

 

[alahol2]

I had a similar problem on a manual Lavac. Took a while to find a small split in the 'fold' of the seat seal. Looks like maybe someone had tried to force the lid open while the vacuum was still in place.
Bought a new seal but whilst waiting on delivery I glued it back together with rubber glue (from puncture repair kit). It's still doing fine service a year later and the spare is still a spare.

 

[timchapman]

I have similar experience to this. Tape over the hole then experiment with different hole sizes until you achieve the level of water in the bowl you want, (after flushing!). The smaller the hole the fuller the bowl will be and the longer it will take for the vacuum to break. After a couple of years the level in the bowl will slowly rise as the vent hole scales up. Just clear it again with your drill bit or whatever.
Can't remember but am guessing that I used a 1.5mm drill bit, it's dependant on your individual installation relative to the waterline.

 

[JerryHawkins]

Don't block the hole

...unless you want a flood! If the hole is completely blocked (as happened to me once) and your loo is below the waterline (as mine is) once you start pumping you just set up a syphon and the loo fills and overflows until you either close the seacock or re-introduce the hole. Just be careful!

 

[red beard]

I had problems with mine for years till I fitted an extra one way valve on the outlet to stop the back flow and another pump on the inlet. Yes you have to pump twice which is not ideal but the lid doesn't need to be closed and it gives you complete control. Works great for me!

 

[Kilter]

...unless you want a flood! If the hole is completely blocked (as happened to me once) and your loo is below the waterline (as mine is) once you start pumping you just set up a syphon and the loo fills and overflows until you either close the seacock or re-introduce the hole. Just be careful!

Similar experience when someone painted over the hole while redecorating!

 

[VicS]

I had problems with mine for years till I fitted an extra one way valve on the outlet to stop the back flow and another pump on the inlet. Yes you have to pump twice which is not ideal but the lid doesn't need to be closed and it gives you complete control. Works great for me!

Properly installed and with a minimum amount of maintenance a Lavac will work well without these modifications.

Just use it and pump out as per the instructions!

 

[capnsensible]

Properly installed and with a minimum amount of maintenance a Lavac will work well without these modifications.

Just use it and pump out as per the instructions!

I reckon on an average of 8 or 9 months liveaboard use before the pump and pipework need a rebore. Have extended that in the last few years by maybe another 3 months using Spanish Agua Fuerte.

Its the non return valve that gets clogged!!!!

 

[prv]

Properly installed and with a minimum amount of maintenance a Lavac will work well without these modifications.

I'm sure it mostly will, but I've often thought that separate control over water in and water out (on any toilet, not Lavacs in particular) would be handy. Sometimes (as a relatively salubrious example compared to other possibilities ) you need to add water to a load of paper which has soaked up what was there, without also attempting to suck it away.

Pete

 

[VicS]

I'm sure it mostly will, but I've often thought that separate control over water in and water out (on any toilet, not Lavacs in particular) would be handy. Sometimes (as a relatively salubrious example compared to other possibilities ) you need to add water to a load of paper which has soaked up what was there, without also attempting to suck it away.

Pete

We had one regular crew member who flushed away the solids before he did the paperwork and then flushed that away separately. Sorry too much info!

 

[red beard]

Yeah I agree completely the non return valve gets clogged and you end up with a bowl of **** and a useless pump, opening it up and clearing it out is not pleasant . Thats why I fitted a second non return valve in the pipe down as close to the bowl as poss. Cheap valve and 5 mins work solved the problem and no more mess!!!