Does anyone have experience in this system I found my air breather hose down in the bilge pumping water, now I understand why the bilge pump runs so much while motoring. I wonder if I should bring it back up above the water line or does it need to exit through a skin fitting? Got me stumped on this one.
Pretty sure it should exit OB that's how it is on my Bavaria, funny little hose exits on transom!
cheers Richard
Select to expand quoteStockie said..
Pretty sure it should exit OB that's how it is on my Bavaria, funny little hose exits on transom!
cheers Richard
And water is pumping out of it or just air?
The vented loop (B) should be installed above the water line. The valve in the top of it may be fouled and allowing water to be pumped from it when the motor is running,,, or if the vented loop is incorrectly installed below the waterline,,, and the vent is fouled, water may flow constantly when the engine cooling water seacock is opened.
water shouldn't flow from it
Like Jonene said it would only pump water if its faulty.
it should just let air in to break siphon when you shut the motor off.
Yeah seems it has a faulty valve. Stupid thing! No wonder the bilge has been working overtime!
Select to expand quotesouthace said..
Yeah seems it has a faulty valve. Stupid thing! No wonder the bilge has been working overtime!
Yep, I had to replace mine after 5 years as it was dripping water into the bilge. I don't have the overflow pipe (A circled) going out - I just let it drip into the bilge. If it is working properly no water comes in anyway!!
Select to expand quoteLazzz said..southace said..
Yeah seems it has a faulty valve. Stupid thing! No wonder the bilge has been working overtime!
Yep, I had to replace mine after 5 years as it was dripping water into the bilge. I don't have the overflow pipe (A circled) going out - I just let it drip into the bilge. If it is working properly no water comes in anyway!!
A circled is the issue it's pumping a stream of water into the bilge when the engine is running.
There's some sort of non return valve inline just below the breather I guess that's the culprit! Tomorrow's job!
Just put one of these in:
www.whitworths.com.au/nanni-diesel-syphon-breaker
Then you won't need the over flow thingy!!
No water should come out unless you push down on the valve when the motor is running - when the motor stops the water flows back down & sucks air in to break the syphoning effect & sink your boat!!
Select to expand quoteLazzz said..
Just put one of these in:
www.whitworths.com.au/nanni-diesel-syphon-breaker
Then you won't need the over flow thingy!!
No water should come out unless you push down on the valve when the motor is running - when the motor stops the water flows back down & sucks air in to break the syphoning effect & sink your boat!!
Good idea I will head to witty in the morning had the Nani one on my previous yacht. Should be the easiest fix.
Select to expand quoteLazzz said..
Just put one of these in:
www.whitworths.com.au/nanni-diesel-syphon-breaker
Then you won't need the over flow thingy!!
No water should come out unless you push down on the valve when the motor is running - when the motor stops the water flows back down & sucks air in to break the syphoning effect & sink your boat!!
Yeah. I have mine in the cabin. When I shut the motor down I religiously listen for the gurgle from the vented loop.
In the diagram where you have marked A on my boat there is a small hose probably about 4mm ID that exits in the cockpit just above the cockpit drains. It is the siphon breaker when the engine shuts down but when the engine runs there is a constant flow of water. As far as I'm concerned it's a visible indication of water flow from the pump. The main hose is 19mm to the water muffler so this is only a small deflection of the water.
Vetus have two types that look the same.
One with a valve and one with a hose.
Find where the other end of the hose was connected and check if the vetus has a valve
Select to expand quoteRamona said..
In the diagram where you have marked A on my boat there is a small hose probably about 4mm ID that exits in the cockpit just above the cockpit drains. It is the siphon breaker when the engine shuts down but when the engine runs there is a constant flow of water. As far as I'm concerned it's a visible indication of water flow from the pump. The main hose is 19mm to the water muffler so this is only a small deflection of the water.
I'm pretty sure it's not a tell tail , yours must be faulty as well. There is a service kit for the valve. My bilge is running every 2 minutes while underway I have suspected it was the packing gland but now this find has proved me wrong.
If the bleed hose is just leaking into the bilge it may also be allowing engine fumes to exhaust inside your boat 
Also the the siphon break is very important when trying to bleed your engine after running out of fuel or other times when there is a lot of cranking and no combustion. What happens in these occasions is, the water pump does its job and continues to fill your exhaust lines and by fill, I mean chockers with water, as there is no exhaust coming from the engine to help it on its way. If you fail to start your engine on these occasions, then you have produced the situation where the anti syphon device becomes critical. Water can flow back into your engine via the exhaust ports in the cylinder head $$$ 
Select to expand quoteCrusoe said..
If the bleed hose is just leaking into the bilge it may also be allowing engine fumes to exhaust inside your boat
Also the the siphon break is very important when trying to bleed your engine after running out of fuel or other times when there is a lot of cranking and no combustion. What happens in these occasions is, the water pump does its job and continues to fill your exhaust lines and by fill, I mean chockers with water, as there is no exhaust coming from the engine to help it on its way. If you fail to start your engine on these occasions, then you have produced the situation where the anti syphon device becomes critical. Water can flow back into your engine via the exhaust ports in the cylinder head $$$
I'm looking it it now , it appears to be inline with the raw water intake and the heat exchanger , not in the exhaust line but good point.
I think the problem has started since I moved the syphion break about 50 mm to fit the diesel heater fuel tank in. 
No i correct my finding it is a break between the exhaust chamber outlet and the raw water from the front of the heat exchanger.
Select to expand quoteRamona said..
In the diagram where you have marked A on my boat there is a small hose probably about 4mm ID that exits in the cockpit just above the cockpit drains. It is the siphon breaker when the engine shuts down but when the engine runs there is a constant flow of water. As far as I'm concerned it's a visible indication of water flow from the pump. The main hose is 19mm to the water muffler so this is only a small deflection of the water.
EXACTLY 
That is how mine is set up, except that it is plumbed into the cockpit drain. No valve of any sort to go wrong, a very small pee lets you know the water pump is working as it should, doesn't affect cooling at all, all in all a win. A little bit like the tell tale of an outboard. You could set it up just like an outboard with the small waterstream through a skin fitting overboard.
Select to expand quoteCrusoe said..
If the bleed hose is just leaking into the bilge it may also be allowing engine fumes to exhaust inside your boat
Also the the siphon break is very important when trying to bleed your engine after running out of fuel or other times when there is a lot of cranking and no combustion. What happens in these occasions is, the water pump does its job and continues to fill your exhaust lines and by fill, I mean chockers with water, as there is no exhaust coming from the engine to help it on its way. If you fail to start your engine on these occasions, then you have produced the situation where the anti syphon device becomes critical. Water can flow back into your engine via the exhaust ports in the cylinder head $$$
A properly installed siphon break is fitted well above the waterline and provides no insurance at all against flooding the engine in the situation described above.
Select to expand quoteUncleBob said..Crusoe said..
If the bleed hose is just leaking into the bilge it may also be allowing engine fumes to exhaust inside your boat
Also the the siphon break is very important when trying to bleed your engine after running out of fuel or other times when there is a lot of cranking and no combustion. What happens in these occasions is, the water pump does its job and continues to fill your exhaust lines and by fill, I mean chockers with water, as there is no exhaust coming from the engine to help it on its way. If you fail to start your engine on these occasions, then you have produced the situation where the anti syphon device becomes critical. Water can flow back into your engine via the exhaust ports in the cylinder head $$$
A properly installed siphon break is fitted well above the waterline and provides no insurance at all against flooding the engine in the situation described above.
Please explain Bob. Are we better of with a working symphony break or not.
Select to expand quoteCrusoe said..UncleBob said..Crusoe said..
If the bleed hose is just leaking into the bilge it may also be allowing engine fumes to exhaust inside your boat
Also the the siphon break is very important when trying to bleed your engine after running out of fuel or other times when there is a lot of cranking and no combustion. What happens in these occasions is, the water pump does its job and continues to fill your exhaust lines and by fill, I mean chockers with water, as there is no exhaust coming from the engine to help it on its way. If you fail to start your engine on these occasions, then you have produced the situation where the anti syphon device becomes critical. Water can flow back into your engine via the exhaust ports in the cylinder head $$$
A properly installed siphon break is fitted well above the waterline and provides no insurance at all against flooding the engine in the situation described above.
Please explain Bob. Are we better of with a working symphony break or not.
A properly installed siphon break is essential to the safe operation of any engine installed below the vessels waterline. The output hose from the heat exchanger needs to extend vertically above the waterline to a vented loop then back down to the exhaust elbow where it flows into the muffler, doing the muffling bit , thence overboard pushed by the exhaust.
The vent in the loop can be the small rubber duckbill valve that is supplied with it when purchased, which requires regular inspection and replacement, or can be replaced with a fitting to accept a small diameter flexible tube that can be run to a suitable drain point, or overboard, keeping this hose as short as practicable. This vent hose is solely there to allow air into the water hose when the engine stops, thus preventing a siphon from occurring. It will discharge water while the engine is running, hence the small diameter hose. Exhaust gases do not enter this hose.
The only safe way to prevent engine flooding during an unsuccessful attempted start with prolonged cranking is to turn off or otherwise restrict the raw water input to the motor. No water in means no water where you don't want it.
Ok problem solved . This my friends is a Non return valve. I can blow slightly through it hence why the water is pumping through. I can suck very clearly through it so obviously it's designed to suck air once the engine is off but once running the non return seals and doesn't allow water or gas to pass! I love boats!
$14 non return valve solved the problem! That is what is built into the vetus water lock that obviously failed in the past and someone fitted a non return in the line. ??
