Why do so many Heads have that Musty Smell?

[Dockhead]

Originally Posted by Cheechako

Pump the toilet often and plenty... will keep the salt water organism issue away. IF the head is meant to shower in, leave something cracked... hatch or port. a little rain wont hurt anything. Weak solution of bleach in a spray bottle is a good idea for cracks and crevices. It doesnt take much bleach to keep things at bay... If your discharge hoses are old and full of urine soaked calcium (or whatever that stuff is!) replace them, then do all t he above with a fresh start.

+1

I think 90% of toilet problems on boats is from not flushing through enough to get clean seawater all the way through the anti-siphon loop. That includes hose calcification problems.

I get an awful stink on board the first time I flush a toilet after the boat has not been used for a few weeks. From the microorganisms which died in the intake side of the system. Then I find that as long as you keep the toilet and heads compartment clean, and flush lots and lots of seawater through every time you use it, it smells absolutely fine.

When you leave the boat, close the intake seacock and flush out the toilet and discharge side with fresh water. Then shut off the discharge seacock. That will help prevent calcified lines. But it won't stop the critters from dying in the intake side.

Another tip -- don't let men stand up to pee in a seaway. The resulting mess is very unpleasant, and will contribute to bad smells if not cleaned up quickly.

Manual toilets, especially the Jabsco ones with a straight rod an "t" handle for flushing, are laborious enough to flush that hardly anyone flushes enough. I made a rough calculation that I needed to pump my previous Jabsco manual toilet 24 times to get clean seawater past the antisiphon loop in my forward heads. Who pumps that much? Can sure make your arm hurt.

A big advantage of electric toilets is that it makes it easy to flush enough water through. The perfect electric toilet (which doesn't exist, probably) would have a timer which would automatically put through the right amount of water.

[noelex 77]

Originally Posted by Dockhead

Another tip -- don't let men stand up to pee in a seaway.

I also insist the ladies sit down

[hanami2]

From the experience gained over years with polyester and metal boats it seems that the bad smell has two origins:
The holding tank of course if not emptied often enough or if some tubing connections are loose.
The salt water used to flush the toilets: if it stays to long it will start generating bad smell, that's one reason, but it will also react with what is evacutated by the toilets to create some kind of brown scale deposit that can even clog the whole stuff.
Hence the "holding tanks + salt water flushing" combination is obviously one of the worst you can get.
Solution: flush with tap water from the tanks and void the holding tanks as often as possible. Each time you can, rince the toilets using chloride with the holding tank by-passed, particularly if you leave the boat for weeks and if the temperature is high.
A drawing of the tubing needed to flush with tap water is can be accessed here: Click HERE! and use the translate button if needed.
All the best.