Draining freshwater tanks

[Lucy]

Hiya,
I have just purchased a 2006 Bavaria 37.

Does anyone know if there is a way to drain the fresh water tanks?  There are 2, fwd and aft.  The water has been sitting in the tanks for considerable time and now tastes quite funky, even chemical like.  It also has a nasty chemical smell to it.
I could turn on all the taps and hoses but am concerned about the unnecessary ware.  There has got to be a stop cock or drain somewhere?  Any ideas?

Thanks in anticipation
Lucy

[Craig]

Lucy,

If you drain your tanks, ensure your hot water system element is turned off if you are on shore power.

You haven't mentioned how long the water has been there or whether this is a recently purchased boat. I know a lot of boats in Europe put Melton or similar chemical into the tanks over winter. This should be drained and the tanks refilled before use. This could be the chemical smell. Some boats have an activated carbon filter installed under the sink tap and this may need to be replaced.

Easiest way to drain tanks is to turn on your taps and just pump out until water starts spluttering, then change to the other tank. Refill tanks and repeat as often as possible until all OK.

The last bit of water may need sucking out through the inspection covers in the top of the tanks. You should be able to get a good look into the tanks through these covers.

When you refill, make sure you bleed all the air out by opening all the taps and ensure the hot water tank is full by having the taps on "hot" as part of the bleeding process.

Craig
"Shirley Valentine"
Gold Coast
Australia

[Lucy]

Thanks for the tips Craig, yes I've just purchased the boat and she has been sitting idle for 8 or so months with 1/2 full tanks.
I was hoping I could just pull out a plug but looks like not so.
Will give all your suggestions a go this avo. 

Cheers
Lucy
'Luce Woman'
Hobart 

[Yngmar]

As Craig said, simply use the freshwater pump to empty the tanks - think of it as a good test for it still working properly.

Once drained you should inspect the tanks via the hatch and clean out anything that isn't water.

Then sterilize the entire fresh water system with a strong bleach solution (household bleach is fine, you won't be drinking this), which you also run into all taps, pump and hot water tank. Don't forget the filler and vent (I just overfilled mine until it came running back out of both). After leaving that for an hour or so, flush everything through with fresh water (twice if you don't like bleach flavoured tea). Details on sterilizing the fresh water system can be found here: http://www.boattest.com/view-news/4218_how-to-make-boat-water-drinkable

Finally, refill tanks adding a standard dose of sodium hypochlorite to prevent anything from growing again. Do this every time you fill the tanks.

[Lucy]

Seems that funky taste was diesel!!   
So here is a little tip for anyone wanting to get that water out fast. 
I put a piece of hose in the water tank and siphoned the sludgy diesel contaminated water in to a bucket sitting in the floor compartment at the base of the companionway.  I ran the taps too, swapping backers over as I went.  Job done in 1/2 the time.

I've now filled and drained the tanks 5 times mixing with dishwashing detergent, gone for a spin on the river a couple of times to swish it around a bit and tonight blasted the clean tank with a good dose of bleach.  Fingers crossed that 2 days of emptying and refilling the tank will cover it.  What a nightmare, but as all the forums I've read say 'at least its not water in the diesel tank'. 
Still, what a pain!

I'm going to put an in-line carbon filter in next.

Thanks for the advice
Lucy

[Ziffius]

Any idea how diesel got in there?

[Lucy]

Simply, the diesel was put in the wrong filling hole prior to me receiving the boat. 
It may have been in there for a very long time?  That I will never know. 

[Craig]

Diesel and water filler caps are the same.

We stuck on a "Water" and "Diesel" sticker beside the filler holes to lessen the chances of this happening.

This is a common mistake, particularly as the signage is merely in the metal and can't be seen at night, or, in the case of many sailors, can't be seen without their glasses on.

If you get signs, I recommend that different colours also help. Our "Water" sig is Blue and our "Diesel" sign red.

Craig
"Shirley Valentine"
Gold Coast
Australia

[Nigel]

Mine look like this, and with a red cap for fuel. The chains have come off and the aluminium is corroded, so they need to be replaced. Apparently made by Roca, but I've been unable to get any more details.