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Old 03-09-2009, 13:16   #16
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I've got two Lavacs. While they have their idiosycracies , I've never had anything like what you report. I'm betting it's a restricted inlet but try some more diagnosis:

Fill the bowl with water from the shower hose or a bucket. Pump with the lid open. It should pump easily. 20 pump strokes should empty it. If not - you have a blockage (hose or vent) downstream or a problem with the henderson pump.

Fill again. Add "solids". A few ice cubes might be good (and melt if there really is a clog). Pump. Should be about as easy as before.

Now try with the lid down. Pump 10 strokes (full strokes about 1-2 seconds per stroke). Stop. You should be able to hear water dribbling into the bowl for about 10 seconds after you stop. If you wait for the lid to release (you shouldn't be able to open the lid for 1-2 minutes) there should be 3-6" of water in the bowl that was sucked in by the suction.

The 10 pump strokes - wait 10 seconds - 10 pump strokes cycle is important with the Lavac. This gives rinse water a chance to fill the bowl. With experimenting you can learn to use fewer pump strokes. With solid waste I do a pump-wait-pump-wait-pump to get an extra bowl rinsing.

My guess is that too fast pumping, not pausing occasionally during pumping, and/or an inlet blockage is not letting enough flush water come in so that the bowl empties of water. Once the water level gets below the top of the bowl exit, air is drawn into the pump with each stroke. Those pulses of air would blow the last bit of waste around inside the bowl.

And an aside on TP. I never worry about TP in a Lavac (I am careful not to fill the holding tank with the stuff). In eight years I've never had a clog in the Lavac. My last head was more like a clog every eight days. Someone on this board claimed a Lavac could swallow a tennis shoe - I assume he was joking but how did he come up with that specific example?

Carl
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Old 05-09-2009, 00:25   #17
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Whoa!

Today, with a bag of TaterTots as a reasonable facsimile of solid waste, I ran a bunch of tests. Nothing seemed to work, so I checked the installation against the owner's manual and found HUGE deficiencies in the way the Lavac was installed on my boat.

The inlet to the pump is at the top, the outlet at the bottom, so the flow is downwards--exactly opposite the instructions. And between the toilet and the pump there are 6 (yes, six) 90-degree PVC elbows, another horrible violation of the instructions.

Clearly the flow of solids is extremely restricted, and the inlet valve is failing to seal properly. The backflushing is hardly a surprise, as a result.

Stay tuned. I've notified the yard that did the work, and suggested we try again.

Dick B.
s/v Rowdy
PSC Flicka #314
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Old 23-09-2009, 01:32   #18
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Originally Posted by glenda2 View Post
We have just had two new Lavac heads installed. They are wonderful except when the need comes to flush more than liquid. After solid waste has been flushed, I raise the lid and it has blasted the entire bowl and lid and seat with waste. Yuck!

I've tried different approaches to pumping. Have added water prior to a flush (there doesn't seem to be enough water in the bowl). 'Have at times pumped almost twice the times stated in the directions as it doesn't sound as if sufficient water is coming in (on the first 8-10 pumps). Have pumped slowly, quickly, or at high speed with no differences.

Our holding tank is above the height of the head in the forward part of the boat, below in the aft head. Both have the same problem.

And of course it is an intermittent problem!


The way yourm post reads makes me wonder if you have plumbed the Lavac correctly.

The lavac uses the pump to pump out the toilet and uses a standard diaphragm bilge pump of the correct size.

The water comes in entirely due to suction créated by the lid being closed.

You talk about lifting the lid. This is almost impossible to do while the toilet is ding its thing as the lid is held closed by the vacuum until the bleed nozzle has allowed enough air in to break the vacuum.

They do work fine with economy grade TP .
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Old 23-09-2009, 06:37   #19
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Dick Behan,

Another thing to check is the check valve (sorry!). I found one of mine had been installed backwards at the factory.

Once you get everything corrected and if you are pumping salt water, make sure you are on a regular schedule of giving the piping and pump a vinegar soak.

Fair Winds,
Mike
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Old 23-09-2009, 10:38   #20
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Thanks to all of you for the responses. After checking out EVERYTHING suggested and thought of, it seems the pump was defective! We are now up and running and all is fresh smelling and a lot easier to keep clean (understatement).

Since we live aboard, this has been a long time very upsetting problem. It could have been solved when that early response suggested we call the manufacturer.

They are great heads and we are now very happy with them.

Thanks all,
Glenda2
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Old 23-09-2009, 10:46   #21
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Great to hear Glenda - having owned Lavacs on my last 2 boats I think you will find that they are a terrific product. As to the faulty pump, that surprises me (as they are just a bilge pump), but if replacing that and not re-running the hoses in accordance with the manufacturer's instructions fixed the problem to your satisfaction, then all is well.

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Old 03-11-2009, 18:53   #22
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I've had Lavacs for 20 years, and they are a great product. The only time I had clogs was when the kids were first learning about TP...
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Old 03-11-2009, 19:51   #23
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Thanks for your reply HHNTR111. We are now very happy with our Lavacs, too. They work much better when the pump is vertical, not horizontal (in the only place we had to put the pump). We had to purchase the electric flush pump in order to be able to put it further away from the head. Now it works very well. We didn't like the extra $250 but the only other option was to tear out our shower.

I'm surprised that you had a problem with TP when your kids were young. I understand you can get rid of old tennis shoes using them! :-)
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Old 04-11-2009, 15:35   #24
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Well, for a while they thought that since some TP is good, more must be better...
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Old 04-11-2009, 17:31   #25
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I think our kids and your
kids must be related!
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Old 25-01-2010, 07:09   #26
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Me too!

Hi Glenda, have you resolved your Lavac problem? I ask because I have the same problem! We purchased a Lavac head for our boat because my husband's other boat in Holland has one and he and his family swear by it. We installed our "new" head last year and my only thought since has been whether or not it is heavy enough to use as an anchor! Yes, solid waste for some reason prefers to come "up" as opposed to going "down"! I am fairly certain that my husbands installation is correct as he is a professional shipwright. The sales rep from Lavac in Florida is trying to assist us in troubleshooting the problem, however I was wondering if you had ever found out what the trouble was with yours.
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Old 25-01-2010, 07:30   #27
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Originally Posted by sheryl1120 View Post
Hi Glenda, have you resolved your Lavac problem? I ask because I have the same problem! We purchased a Lavac head for our boat because my husband's other boat in Holland has one and he and his family swear by it. We installed our "new" head last year and my only thought since has been whether or not it is heavy enough to use as an anchor! Yes, solid waste for some reason prefers to come "up" as opposed to going "down"! I am fairly certain that my husbands installation is correct as he is a professional shipwright. The sales rep from Lavac in Florida is trying to assist us in troubleshooting the problem, however I was wondering if you had ever found out what the trouble was with yours.
It might be worth checking that the pump has been installed the right way round, i.e. the joker valve must be at the top if the pump has been installed vertically. If not the pump drains when not in use, causing an airlock, then when you start pumping can't prime and the waste can be pumped back to the bowl. It's easily done, especially if installed by a first timer, and there's only a small note in the installation instructions. Makes a hideous mess!

And how do i know this......
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Old 25-01-2010, 07:32   #28
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Quote:
Originally Posted by sheryl1120 View Post
Hi Glenda, have you resolved your Lavac problem? I ask because I have the same problem! We purchased a Lavac head for our boat because my husband's other boat in Holland has one and he and his family swear by it. We installed our "new" head last year and my only thought since has been whether or not it is heavy enough to use as an anchor! Yes, solid waste for some reason prefers to come "up" as opposed to going "down"! I am fairly certain that my husbands installation is correct as he is a professional shipwright. The sales rep from Lavac in Florida is trying to assist us in troubleshooting the problem, however I was wondering if you had ever found out what the trouble was with yours.

Post #20 in this thread by Glenda2:

Thanks to all of you for the responses. After checking out EVERYTHING suggested and thought of, it seems the pump was defective! We are now up and running and all is fresh smelling and a lot easier to keep clean (understatement).

Since we live aboard, this has been a long time very upsetting problem. It could have been solved when that early response suggested we call the manufacturer.

They are great heads and we are now very happy with them.

Thanks all,
Glenda2
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Old 25-01-2010, 10:02   #29
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Lavac

Hi again, funny, my husband was thinking it was the pump all along! We will get back to the manufacturer and see what he thinks! Thank you for your quick reply!
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Old 25-01-2010, 13:10   #30
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We have the Lavacs with new Jabsco Electric pumps. These are equipped with 2 Joker valves unlike the old version which is one joker and one flapper. They work fine but the valves only seem to last about 6 - 8 months of live aboard use.

The symptoms of their degradation in performance are exactly as described in the earlier posts. We started experiencing problems about 8 months after replacing the original pump. On the premise that the pump was as-new, I went through and replaced all the hoses to no avail. Finally as a last resort, I purchased the repair kit and changed the valves and diaphragm (all which, btw, looked just fine) and bingo! it worked.

We do love these Lavacs, but they do need fine tuning to ensure that there is enough water in the bowl - but not too much. They are indeed bullet proof when all the planets are in alignment.
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