Originally Posted by Francois
Can some of you guys explain to me how a Type 1 & 2 MSD sanitation device works?
You can do a web search and find out all you need to know (and more) about these systems.
I bought my 1985 Chris Craft boat about 6 months ago and have been using her monthly with family (which has 3 heads).
I have been pumping out the tank regularly and noticed "crap" smell is more frequent inside and outside (SB).
I thought this system was no longer in function, and since my main sewage tank is filling out normally, I did not bother.
Here's a couple more points of my system:
* Each head is equipment with a "timer" which we never use
* I don't see a 12V nor a 120V breaker switch for this system identified on my panels. Now, I do have several unidentified 120V (and 12v) breakers which I sometime turn on to see what they are
* I see another smaller tank not too far from my sewage tank which I believe is this Type 1 or 2 MSD device
* My main sewage tank is equipped with a Y valve for overboard discharge (which I keep in off position). Just beside, I see another through hull valve in OFF position which I can't figure out where it goes (maybe it is related to the second MSD...)
- and finally, my sewage tank got completely filled up to the max twice over this last 6 months... this surprised me since I had just pumped everything out (did this liquid come from the other MSD ??)
With everything you've described and the questions you are asking, I think you need to find a person locally who is experience in marine sanitation to actually look at your boat, see if anything is wrong with your system, and explain it all to you. Random answers on a web forum are likely to leave you even more confused.
This is a good book on marine sanitation systems in general and may provide some answers for you: