Fresh water flushing

ingenious

Active member
Joined
14 Jan 2025
Messages
305
Visit site
I've been looking at the list of advisories on the surveyor's report on my boat. Most are fairly straightforward but one that wasn't as clear was:

- WC is seawater flush only

Apparently this is as factory design but it is a common modification to install a valve to switch between seawater and freshwater as the seawater in bays and lagoons often has a lot of bacteria and insect larvae, particularly in summer, which can cause bad smells and blockages.
I found a thread showing how to do it on the Jeanneau owners forum but I don't really want to be ripping into the boat having only just got it so, if I do need it done, would probably get the workshop in the port to do it.
Is it worth doing
Thoughts from others in SoF?
 

Momac

Well-known member
Joined
7 Feb 2008
Messages
7,244
Location
UK
Visit site
My boat has a shower hose which pulls out from the washbasin tap which I use to flush the toilet.
Failing that as a possibility a bucket or bowl or jug of fresh water could be used to flush the toilet perhaps once a day and immediately before leaving the boat for any length of time.
 

Momac

Well-known member
Joined
7 Feb 2008
Messages
7,244
Location
UK
Visit site
I upgraded from an electric flush to a manual pump.
If I recall correctly the complete manual pump cost no more than the service kit for the electric pump. Keeping it simple isn't a bad philosophy to adopt for boats .
 

Sticky Fingers

Well-known member
Joined
21 Feb 2004
Messages
6,770
Location
Home Saffron Walden, boat Swanwick.
Visit site
I upgraded from an electric flush to a manual pump.
If I recall correctly the complete manual pump cost no more than the service kit for the electric pump. Keeping it simple isn't a bad philosophy to adopt for boats .
Well, we can happily agree to disagree on this. I’d never ever ever have manual pump loos again.
 

OCuea

N/A
Joined
8 Jun 2024
Messages
461
Visit site
I think I was fortunate in have a loo that never smelled. Seawater flush. Plenty of flushing after use. Blake’s seacocks. Never smelled at all……I did not fit it but it had all the loops etc etc . I smelled worse in Summer sweat than the loo…… no shower. Delivered an expensive yacht once (macerator etc etc) - the actual loo broke !!!!!

£100k versus £100 .

Good porta Porto perhaps? Holding tank etc etc all in one ?!
 

Sticky Fingers

Well-known member
Joined
21 Feb 2004
Messages
6,770
Location
Home Saffron Walden, boat Swanwick.
Visit site
I think I was fortunate in have a loo that never smelled. Seawater flush. Plenty of flushing after use. Blake’s seacocks. Never smelled at all……I did not fit it but it had all the loops etc etc . I smelled worse in Summer sweat than the loo…… no shower. Delivered an expensive yacht once (macerator etc etc) - the actual loo broke !!!!!

£100k versus £100 .

Good porta Porto perhaps? Holding tank etc etc all in one ?!
You’ve presumably never sailed with a lady friend.
 

harvey38

Well-known member
Joined
27 May 2008
Messages
2,062
Visit site
We spent £5k to have two Vetus 12v electric toilets fitted along with a 200l stainless holding tank, new pipework, skin fittings and conversion to fresh water flush.

Five years on on and no smells and no issues.
 

john_morris_uk

Well-known member
Joined
3 Jul 2002
Messages
28,234
Location
At sea somewhere.
yachtserendipity.wordpress.com
Freshwater flush is a game changer for boat bogs. Get it professionally done, change all the hoses at the same time and scrap the seawater flush, and if the loo is a manual pumper then change for a Tecma or Planus electric. The best upgrade you’ll ever make.
It might be if you don’t sail across oceans. Carrying enough water to flush the toilets when there’s gazillions of gallons of perfectly good seawater within a meter or two is a challenge I don’t have to face. I know we’ve got a watermaker but if that breaks down and fresh water flushing is all we’ve got then I’ve got real problems mid ocean.
 

Sticky Fingers

Well-known member
Joined
21 Feb 2004
Messages
6,770
Location
Home Saffron Walden, boat Swanwick.
Visit site
It might be if you don’t sail across oceans. Carrying enough water to flush the toilets when there’s gazillions of gallons of perfectly good seawater within a meter or two is a challenge I don’t have to face. I know we’ve got a watermaker but if that beaks down and fresh water flushing then I’ve got real problems mid ocean.
That’s a fair point. Agreed.
 

OCuea

N/A
Joined
8 Jun 2024
Messages
461
Visit site
It might be if you don’t sail across oceans. Carrying enough water to flush the toilets when there’s gazillions of gallons of perfectly good seawater within a meter or two is a challenge I don’t have to face. I know we’ve got a watermaker but if that beaks down and fresh water flushing then I’ve got real problems mid ocean.
You have it all it compared to many. Congrats.
 

OCuea

N/A
Joined
8 Jun 2024
Messages
461
Visit site
I don’t understand this loo smell? Did I buy boats that had well installed loos with looping hoses or whatever? I flushed a lot of times with seawater and sometimes would not return for a couple of weeks mid Summer, but no smell. I always shut seacocks. Just luck? Of bought ok boats?
 

john_morris_uk

Well-known member
Joined
3 Jul 2002
Messages
28,234
Location
At sea somewhere.
yachtserendipity.wordpress.com
You have it all it compared to many. Congrats.
Not so quickly with the congrats.

Recent problems;

1. The ‘fresh water’ we’ve filled our tanks with perhaps wasn’t as fresh as we’d like and the water now stinks of sulphur dioxide. My first attempt at shock treatment with a gallon of bleach pumped through etc resulted in the insulation in the Calorifier immersion heater breaking down. Can’t be used any more ad it trips the RCB on the panel…. We thought the bleach had cured things but the smelly water has just returned.

2. You may have seen the thread a few weeks ago where I described our domestic battery bank failing and leaving us mid passage at night with boiling batteries and sulfur dioxide fumes everywhere.

3. I’ve just spent the day running a new upgraded cable to our aft shower pump out pump. Two days ago I was adding vents to the under bunk space where the inverter:charger is fitted to try to keep it cool.

4. Last week I was stripping down and repairing both the winches on the davits. They’re working again now but it made us realise how much we used them..!

I’m not looking for sympathy in the least, but whoever said ‘blue water sailing’ is code for ‘fixing your boat in nice places’ knew what they were talking about.

If you want to come and help me catch up with a whole load of sanding and varnishing in exchange for a few weeks sailing in the Caribbean get in touch!
 

OCuea

N/A
Joined
8 Jun 2024
Messages
461
Visit site
Not so quickly with the congrats.

Recent problems;

1. The ‘fresh water’ we’ve filled our tanks with perhaps wasn’t as fresh as we’d like and the water now stinks of sulphur dioxide. My first attempt at shock treatment with a gallon of bleach pumped through etc resulted in the insulation in the Calorifier immersion heater breaking down. Can’t be used any more ad it trips the RCB on the panel…. We thought the bleach had cured things but the smelly water has just returned.

2. You may have seen the thread a few weeks ago where I described our domestic battery bank failing and leaving us mid passage at night with boiling batteries and sulfur dioxide fumes everywhere.

3. I’ve just spent the day running a new upgraded cable to our aft shower pump out pump. Two days ago I was adding vents to the under bunk space where the inverter:charger is fitted to try to keep it cool.

4. Last week I was stripping down and repairing both the winches on the davits. They’re working again now but it made us realise how much we used them..!

I’m not looking for sympathy in the least, but whoever said ‘blue water sailing’ is code for ‘fixing your boat in nice places’ knew what they were talking about.

If you want to come and help me catch up with a whole load of sanding and varnishing in exchange for a few weeks sailing in the Caribbean get in touch!
Err, I will stick to gardening, sorry.
Sure you will get it fixed.
Did not know of the problems…… imagined sun and breeze and heat too much heat in worst case.
Citric acid or the steriliser used in home brewing not more suitable than bleach? I have never owned a reverse osmosis water maker so I am sure you know more. It is raining and cold here in uk
 

ingenious

Active member
Joined
14 Jan 2025
Messages
305
Visit site
Freshwater flush is a game changer for boat bogs. Get it professionally done, change all the hoses at the same time and scrap the seawater flush, and if the loo is a manual pumper then change for a Tecma or Planus electric. The best upgrade you’ll ever make.
Well, that's a jump I hadn't thought of.
How much fresh water do you use per day normally?
The NC11 has a 250 litre tank but there are comments on the owners group about the guage being very inaccurate as the tank is very wide and shallow so you don't want to bank on using it all.
Already has electric flush but I think it's Jabsco.
 

Refueler

Well-known member
Joined
13 Sep 2008
Messages
21,837
Location
Far away from hooray henrys
Visit site
I don’t understand this loo smell? Did I buy boats that had well installed loos with looping hoses or whatever? I flushed a lot of times with seawater and sometimes would not return for a couple of weeks mid Summer, but no smell. I always shut seacocks. Just luck? Of bought ok boats?

I too have had and have boats with SW flush ... smells ?? Nothing other normal odour left after use ! Bog itself ? Fine.

IMHO plenty of good flushing ...

My C38 has flush to sea and to holding tank ... whichever is used - at end of day - a good flush to sea to clear pipes etc is a good idea. To Tank ? Then a dash of bog fluid ..

When leaving for winter - after draining down system .. a decent strength diluted anti-freeze through both to sea and to tank ... leave and be content to leave till spring.
 

simonfraser

Well-known member
Joined
13 Mar 2004
Messages
7,548
Visit site
it's the SW in the pump left alone for a while that creates the major smells (treatment available for this), pump it out and that is the end of the smell
plenty of fresh air on the boat to take that away in a min or two
 

ss2016

Active member
Joined
24 Jul 2016
Messages
157
Visit site
Our regime is to run plenty of fresh water from the shower head down the loo when we are back in the marina. That seems to pretty much solve the problem.
Apart from that plenty of sea water when out and about.
 
Top