Blake’s Lavac Can Someone Please Explain How it Works

KeelsonGraham said:
…..Oh! I must have got it completely wrong, looking at it through a cramped inspection hatch. I thought the pump was plumbed in series with the inlet side of things. Now, looking at the PDF it looks like it’s actually plumbed in series in the outlet side of things. So, all the waste goes through the pump’s chamber. Is that correct?
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Yes: you did have it completely wrong!!

Yes: your penultimate sentence is correct. :cool:
 
alahol2 said:
The Henderson pump also acts as a macerator which means the 'doings' are nicely minced for the fishes/seahorses.
The Lavac is way less problematic than Jabsco, Raritan et al. Fitted 15/16 years ago and never a problem. Brilliant piece of kit.
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Yes, could not agree more. Excellent, simple piece of kit. Had one for 20 years plus, changed the lid seal once, that’s it. Have seen plenty of Jabsco’s give trouble with their valves, glands etc leaking.
Probably would change to a Lavac if I bought a boat fitted with anything else. Like most things if installed correctly - will work correctly !
 
Mine the seat the following mmorning will still be sucked shut, but by small lift between the 2 hinges, the vacume is easily broken
 
oldmanofthehills said:
I still hate them. Either the lid seals leak so no flush is drawn through, or vacuum dies away so slowly that next urgent user has to hop around clutching themselves or try and break the seal in order to lift the lid

Glad I have now fitted a Jabsco
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Haha, I stripped out Jabsco toilets because the pumps are so unreliable. Installed Lavacs as they were so super reliable in the last boat ?
The little vacuum break hole on the inlet pipe can be varied to suit. If that's all I had to deal with on Jabsco toilets I would be delighted?
 
vic008 said:
Mine the seat the following mmorning will still be sucked shut, but by small lift between the 2 hinges, the vacume is easily broken
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If the vacuum does not decay reasonably quickly (from memory within a minute or so) the air vent at the top of the inlet hose loop is blocked , or not fitted. Prying the lid open before the vacuum has gone will damage the seals.
There will also be far too much water left in the bowl.
Check and unblock the vent.
 
Never had my Blackes Lavac block in 8 years of oning Concerto and it is 41 years old. Last year I had to change the Henderson pump as a part broke. Must get round to getting a replacement part so it can be a spare. On board I also have a holding tank, but to empty this there is another Henderson pump. Now you know why I want a spare pump.

Over all the years of sailing I have done, all the toilets that got blocked were of the Jabasco type pump. Cheap and cheerful, but will get blocked at some time in the future.

Who loves unblocking a loo, especially if you did not block it.
 
CapPugwash said:
Another happy Lavac owner here.

Does anyone know if you can buy replacement lids? Ours works fine but the plastic has faded and doesn't look so nice.
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Yes, LeeSan but dont look at the price unless you are lying down and have taken all your medication. .. By the time you add on the price of a seal its nearly as much as a whole new Jabsco

I suggest you find a suitable paint!
 
I had a Lavac on my last boat, the new boat has a Jabsco which I've serviced. I've promised myself that as soon as there is a flicker of a problem with the Jabsco it will be switched for a Lavac. I never had any problems with the old one, and I think the Jabsco is far too complicated.
 
KeelsonGraham said:
I don’t understand this response. The inlet from the seacock goes to one side of the pump. The outlet from the pump goes to the bowl. So, I can see how inlet water is drawn by the pump through the seacock through the pump and into the bowl.

The pump absolutely doesn’t expel waste via the inlet seacock.

So what forces the waste out of the bottom of the bowl???????
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My take on it is that when the lid is sealed the bowl becomes at one with the plumbing, effectively making an uninterrupted path for the water to flow in through the seacock, through the pump and out to sea or holding tank, taking the contents of the bowl with it. Simples!
 
doug748 said:
I like them as well, in fact if I bought a boat with anything else I would change it for a Lavac.

.
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My previous boat came with a Lavac, and I thought was excellent. My current boat came with a Jabsco, and I soon afterwards became the owner of a spare Jabsco, FOC, which I keep fully serviced, ready to swap out for the existing one, should it give trouble, whereupon, after being serviced, this one becomes the spare, so like it or not, I am stuck with the status quo.
 
VicS said:
If the vacuum does not decay reasonably quickly (from memory within a minute or so) the air vent at the top of the inlet hose loop is blocked , or not fitted.
There will also be far too much water left in the bowl.
Check and unblock the vent.
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Thanks. I've been wondering (8 years) why there is a lot of water after flushing. Something else to check
 
mattonthesea said:
Thanks. I've been wondering (8 years) why there is a lot of water after flushing. Something else to check
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Clean the air bleed.
They are actually supplied with two different sized holes. If cleaning the existing one does not solve that problem consider the possibility of fitting one with a larger hole or carefully enlarging the hole.
 
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