I have exactly the same problem as bec.chandler and others in this tread.
I have read with great interest all of the contributions on this thread and would like to explain my system and what I have done, with some result but not cured.
The vessel is a Bayliner Avanti Express 3485, build year 1996. It was imported to the UK from Florida
USA. The boat is used mainly in fresh water (rivers & broads).
When I bought it 5 years ago, it was fitted with a brand new Jabsco
model 27354 electric
toilet. The flush water was taken from river via a filter and the discharge runs horizontal through the bulkhead then rises to the top of the holding tank (no loop).
I foolishly poured bleach / disinfectant directly into the bowl with the result of damaging the seals
and having to strip down & rebuild
toilet. In the UK we use a blue formaldehyde based holding tank de-odorant which does not damage the seals
, don’t know what you use in the US.
I cured the smells outside of the boat by fitting a ‘LeeSan’ Microvent Holding Tank Breather Filter.
However the head itself (nowhere else on the boat) smells every time it is flushed.
I then disconnected the raw water
flush feed and now only flush with fresh (potable) water. I also fitted a ‘LeeSan’ Head Treatment System to treat the incoming flushing
water to destroy the Micro-growth. It also turns the flush water blue and scents it. Smells nice if you just add water, until you flush.
As I still got ‘black bits’ in the bowl from the flush water I ripped out the original black rubber hose and connected the fresh water / HTS directly to the white plastic hose which was fitted with the new toilet. So the flush water circuit is now,
- Potable water supply to pressurization pump – solenoid valve operated by electric
toilet switch – non return valve – head treatment bottle – white plastic feed pipe – toilet bowl.
The head still smelt every time it was flushed!
I noticed bubbles in the bowl after a flush and assumed the Jabsco ‘Joker’ valve was allowing gas from the discharge pipe back into the bowl, particularly as the discharge pipe rises about 3 feet to the top of the holding tank (there must be foul water in this pipe unless you flush an impractical amount of water through it) so fitted an additional ‘Henderson In-Line Check Valve’ in the discharge pipe close to the bowl.
It stopped the bubbles but the head still smells every time it is flushed!
I then tried, as recommended by ‘LeeSan’ Clean and Green Sachets. It was worse than the blue formaldehyde based holding tank de-odorant!
I was not happy with the ‘pump out’ at my usual place as it took to long and you could see on the level indicator that the holding tank level went down very slowly. I suspect that the tank was not being cleaned out properly. I now when it is a good pump out as it sucks the water out of the head bowl. I changed to a new pump out station with really good results. The head hardly smells at all when first flushed after a pump out, even if the boat has been left unused for weeks, but starts to smell after a few days use, again only when flushed, even having not used the head but just flushing
I am at the end of my tether; don’t know what else I can do? The only thing from the tread I have not tried is the vinegar treatment, with my system, would this help?
Any help would be gratefully received, Terry.