Galley salt water and bad smell

[Roberto]

At the galley, we have a sea water faucet with its own foot pump.

Every time we use it, there is an awful rotten egg smell (H2S maybe? ): it goes away after a dozen pump strokes but everyone in the cabin goes "oh no you've used the salt water pump again"

I have cleaned the pump, changed diaphragm and all hoses (sanitary hose) but to no avail: the following day the smell is always there.
If one uses it every couple of hours no problems, but washing/pre-rinsing dishes at lunch means that if we use it after dinner it will stink already

Hose runs are very short, I'd say 50-70cm. They run under the sink where the fridge compressor is too, so maybe it's the warmish temperature ?

It's a real pity because the sea water faucet is very useful (dishes pre rinsing, one half sea water when cooking pasta :smile: , washing vegetables, etc), has anyone had the same problem and found a solution ?


btw, we have absolutely no rotten salt water smell in the toilets, even when pumping for the first time after a couple of weeks..

 

[vyv_cox]

I guess that the pump skin fitting is close to the galley sink discharge? Sounds like it might be drawing in food particles which decompose in the tubing.

 

[KellysEye]

I assume the inlet is a through hull or a T off one. Take the hose off the throughhull, get a bucket of fresh water. Add bleach, (for 40 gallons of water you only need to add a quarter cup of bleach, so you'll need about one fortieth of a quarter cup. Use the pump until the bleach comes through and seal the hose at the bucket end. Leave for a minimum of 12 hours and absolutely no more than 24 hours. That should do it.

 

[Ubergeekian]

At the galley, we have a sea water faucet with its own foot pump.

Every time we use it, there is an awful rotten egg smell (H2S maybe? ): it goes away after a dozen pump strokes but everyone in the cabin goes "oh no you've used the salt water pump again"

I have cleaned the pump, changed diaphragm and all hoses (sanitary hose) but to no avail: the following day the smell is always there.
If one uses it every couple of hours no problems, but washing/pre-rinsing dishes at lunch means that if we use it after dinner it will stink already

Hose runs are very short, I'd say 50-70cm. They run under the sink where the fridge compressor is too, so maybe it's the warmish temperature ?

Sounds as if you have a chemical reaction in the water in the pipe. I can't offhand think of anything which might be the other side of the reaction - pump internals? sealant? - so my guess is that it's the heat. What about teeing off with a changeover valve near the tap and a tee in the sink outlet so you can send a few pumps straight through before diverting to the tap?

 

[whipper_snapper]

Sounds as if you have a chemical reaction in the water in the pipe. I can't offhand think of anything which might be the other side of the reaction - pump internals? sealant?

I don't think so. Hydrogen sulphide is an unmistakable 'bad egg' smell and is almost certainly produced by anaerobic bacteria living in the salt water trapped in the pipe. The high temperatures certainly won't help. Bleach will be a temporary fix, but there is no saying how long its effect will last. Is there a 1-way valve in the system to keep the pump primed ? If so, get rid of it. THat will cause a column of static seawater, and will also have surfaces just right to encourage growth. Your pump will need to work a bit harder, but that is a small price to pay.

 

[KellysEye]

>Bleach will be a temporary fix, but there is no saying how long its effect will last.

It depends how much the pump is used. Every day, no problem the smell won't come back. May get away with a week but probably no more if the boat is warm. You get the same if the fresh water tanks are left too long, but that's months.

The basic problem is that if you leave salt water, or indeed fresh water, in the pipes/pump/tap for a long time it begins to smell. The only solution I know is bleach and regular use.

 

[Matt341]

Had the same problem on the toilet on our previous boat, the toilet was an RM and after much trial and error we found that the smell was coming from the sea water inlet pipe, it only did it after the toilet hadnt been used for a week or so, as the smelly water was sucked through and into the toilet bowl this is when the smell occured. There wasnt really much that could have been done as it was on the inlet and not the outlet. The only option was fitting a Y valve and pumping fresh water through before leaving.

We havent had the problem on the Lavac toilet on our current boat, probably because when you flush it the lid is sealed so no smell can escape.

Im thinking you have this problem in the salt water tap and that it is smelling sooner (matter of hours instead of days) because of the heat off the fridge components.

As others have said, it could be worth fitting a Y piece to flush fresh through, this is ok for once a week but to do this once or twice a day could be a lot, and defeat the object of having a sea water tap as you would then be using fresh water just to keep the salt water tap from smelling.

Ian.

 

[rivonia]

The problem you are having is BACTERIA multiplying in the pipe. Answer...Fit a 'T' piece as close to the inlet as poss, fit an on off valve,fit a plastic tube. After use close sea cock put tube from 'T' piece into a bowl of fresh water with a little disinfectant(bleach) and pumpit through. No more smells EVER.

Peter

 

[whipper_snapper]

I am sure that's right. But the problem is that he has a column of water trapped and without oxygen. Flushing it through at such intervals would be a pain. If there was a simple way to break that column, the problem would go away. I would leave the tap open, remove any 1-way valves and leave the seaock open. That way there will just be water sloshing around in the pipe between skin fitting and water line height. The fact that it will be sloshing around will encourage air to mix from the empty pipe above. I think that will fix it.

 

[Roberto]

thanks

thanks all for the suggestions

In my case I have some doubts about bleach: when I stripped the pump and changed the hoses, everything new and clean, one day later it was already foul.. :angry:

The stinkiest part seems indeed the column of water between the pump and the faucet: the first few pump strokes are the worst; there is no additional one way valve, there surely must be inside the pump but I wouldn't really know how to take it off, nor if the pump would work without it ?

it's the typical Whale foot pump

Maybe put a T immediately after the pump outlet, to get rid of salt water once the pump has been used ?

 

[Salty John]

We had exactly this problem and were advised to wrap the pipe between pump and faucet with foil, or change to a black hose. This seems to have done the trick. Apparantly it was algea in the pipe, encouraged to grow by the presence of light through the semi-clear pipe.
If your pipe is clear it may be worth a try?

 

[rivonia]

thanks all for the suggestions

In my case I have some doubts about bleach: when I stripped the pump and changed the hoses, everything new and clean, one day later it was already foul.. :angry:

The stinkiest part seems indeed the column of water between the pump and the faucet: the first few pump strokes are the worst; there is no additional one way valve, there surely must be inside the pump but I wouldn't really know how to take it off, nor if the pump would work without it ?

it's the typical Whale foot pump

Maybe put a T immediately after the pump outlet, to get rid of salt water once the pump has been used ?

YES put the 'T' piece after the pump as close to it as you can then follow my previous instructions

Peter

 

[vyv_cox]

The stinkiest part seems indeed the column of water between the pump and the faucet: the first few pump strokes are the worst; there is no additional one way valve, there surely must be inside the pump but I wouldn't really know how to take it off, nor if the pump would work without it ?

A positive displacement pump such as yours does not need a check valve. The discharge valve of the pump is one anyway.