Vacu flush loss of vacum

Feb 6, 2010
138
hunter passage456 kemah
Encountering a new issue with one of my vacu flush heads...these are 18 yr old units that I've maintained since 2007. Recently one of the heads has lost a great deal of suction. It still clears but without the aggressive suction as normal
I have changed the bowl seal..replaced the piston / plunger on the low profile vacum unit. I changed the duck valves about 6 months ago. This unit has had a issue of losing vacum ...in addition the pump would not shut down so I would turn it off at the breaker which is close to the head so it wasn't a big issue , but now with the inability of the unit to gain suitable suction regardless how long it runs is a issue. I'm getting no water loss in bowel so I know it's not the bowel seal. Also looking at the amp meter it is only pulling about 4 amps.as it pumps abou half of my other unit...any ideas Peggy?
 
Dec 2, 1997
8,166
- - LIttle Rock
Most of your symptoms, causes and cures, are described in the troubleshooting guide that's included in every owners manual. The VF has changed so little except cosmetically since Mansfield Plumbing introduced it in 1978 (Mansfield spun off their marine toilets division to SeaLand Technology in 1984) that the same trouble shooting guide works for all years, all models. I can send you a troubleshooting guide if you'd like to send me PM that includes your email address (no way to attach anything to a PM). You'd have known that replacing the bowl seal is only necessary if the bowl does NOT hold water...you've said yours does.

Meanwhile, I'm guessing that you have multiple problems. A failed/worn out vacuum tank switch (average lifespan can be anything from 2-5 years) will prevent the pump from shutting off when sufficient vacuum has been achieved. A worn out/leaking pump bellows will prevent the system from achieving suffficient vacuum. That can also be due to an air leak in the plumbing. That's fairly easy to check without the need use a vacuum tester gauge: squirt a LITTLE shaving cream on every hose connection...flush the toilet. The suction--even if low--will pull shaving cream into any connection that's leaking...it'll just sit there on all that aren't leaking.

A volt meter on the pump while running will tell you whether it's GETTING a full 12v, not how many the pump is pulling. Low voltage TO the toilet is caused by a power source (battery) that's not putting out enough. Low voltage can damage the pump motor.

You replaced the duckbills 6 months ago...did you begin to experience low vacuum before or after your did that? Have you checked all 4 since then to make sure no TP or waste is keeping any of 'em open? Are you putting enough water through the system..never mind what SeaLand claims you can get away with...90% of problems with VF are result of using waaaay too little to keep the duckbillls and pump bellows cleaned out. When I send you the troubleshooting guide I'll also send you my article "VacuFlush 101" that explains how the system works and how much water it really needs to prevent problems with it. (btw,...you may not know that VF was the toilet on my last two boats and I was a dealer for nearly 10 years, so I'm INTIMATELY acquainted with it!)

--Peggie
 
Feb 6, 2010
138
hunter passage456 kemah
Thanks...the symptom seems different then other issues because when it was creating strong vacum it dissipated quickly...but bowel seal wasn't the issue so I'm not sure where to look...the choker valves would prevent the vacum in the first place right? The rapid loss of vacum with the bowel seals holding is what puzzles. Me as you suggested the pressure sensor is / was im sure the reazon for the not shutting off..but why the vacum went fast is a issue. I'm going to check the choker valves tomorrow and will report.