Raw water in intake hose stinking?

[Dr. D]

When we went on the sea trial of our 2001 Jeanneau 37, we noticed after flushing the Jabsco electric head there was a smell in the air. The broker attributed this to raw water standing in the intake hose. He said flush the head a few times and the smell will clear. That kind of works..... Or was the broker pulling something out of thin air?

Now we are noticing the smell is stronger and hangs around longer. I saw the thread on the downstream hose becoming permeated and emitting a smell. How common is that?

What other possible cause?

[JimsCAL]

Very common. If there are some little creatures in the water (like brine shrimp) they die in there and begin to smell if the head hasn't been used in some time.

[Tellie]

Agreed, very common with salt water flush heads. There are a lot of very small microscopic living things in salt water. If this growth laden water is left in the intake lines these animals die quite quickly from oxygen deprivation. As they decompose that all too familiar hydrogen sulfide (rotten egg) smell permeates the boat on the next flush. Down here in the south this can happen in as little as 24hrs.

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[Panacea2183]

Could be raw water as stated above, but if it does not go away after a fresh flush suspect hoses.
After chasing smells and cleaning with bleach, vinegar, head chems,etc.
Finally bit the bullet and replaced all hoses, smell gone.

Could never really isolate the smell on the boat, but when I took the old hoses (50 ft of it) to the curb for the trash man, could smell it whe I went out the front door of the house, Whew bad.
This is a job you don't want to do twice buy the best hose you can, most are only good for a few years.

[peghall]

If the "smell in the air" is confined to the head, and is coming from the bowl with the first few flushes after boat has been sitting, yes...stagnant sea water and dead and decaying micro (and sometimes not so micro) animal and/or vegetable sea life left to sit in the intake line, pump and channel in the rim of the bowl is the culprit. That the odor seems to be stronger and hanging around longer is a strong indication that you've pulled in weeds or a minnow that's taking more decompose. (Worst I ever encountered was the remains of a baby octopus).

Step 1. Buy a a couple of quarts of distilled white vinegar....and a bucket if you don't have one.

Step 2: Put one quart of the vinegar into a bucketful of clean FRESH water.

Step 3: Disconnect the toilet intake line from the thru-hull (might be a good idea to close the seacock first)...stick into the bucket of vinegar and water, flush the whole bucketful through the toilet.

That should clean out the system.

If you search the archives, you'll find a lot of discussion about a way to prevent this problem by re-routing the head intake line to tee into the head sink drain line. That will allow you to flush with sea water normally, but rinse all the sea water out of the system before the boat will sit by closing the drain seacock and filling the sink with clean fresh water ...flush the toilet. Because the seacock is closed, the toilet will pull the water out of the sink, rinsing out the whole system...water poured into the bowl doesn't recirculate through the intake, it just goes out the discharge.

[Dr. D]

Thanks for the suggestions!

[Akapeterc]

It definitely depends on the water quality when travelling up north smell disappears but when we return to Lake Macquarie instantly the smell comes back

[boeing1]

I use fresh water to flush, I keep a jug of fresh water in the head, keeps odors out.