Leaking anti syphon device

[Kwik Decision]

I've finally traced the source of water which gathers under the engine each time it is used to the anti syphon thing leaking from the vent on the side. There is a length of pipe on the vent, poked down behind the engine so it wasn't obvious. It is a Vetus one like this:

http://www.force4.co.uk/1122/Vetus-Airvent-Anti-Syphon-Device.html

I've taken the top off it, and the valve moves freely, but it still leaks. Does anybody have any suggestions as to how I can fix it, or do I need to spend a fortune on a new one?

Thanks

 

[VicS]

I've finally traced the source of water which gathers under the engine each time it is used to the anti syphon thing leaking from the vent on the side. There is a length of pipe on the vent, poked down behind the engine so it wasn't obvious. It is a Vetus one like this:

http://www.force4.co.uk/1122/Vetus-Airvent-Anti-Syphon-Device.html

I've taken the top off it, and the valve moves freely, but it still leaks. Does anybody have any suggestions as to how I can fix it, or do I need to spend a fortune on a new one?

Thanks

Do Vetus offer service kit for it ???? Perhaps not.. they may just expect you to replace the whole thing.

You could consider taking the gubbins out of the valve and converting it to the H type which discharges a pee stream overboard or into a cockpit drain.
You'll then have no problems with it dribbling into the bilge or failing to notice if it gets bunged up

 

[PetiteFleur]

Remove the top, throw away the valve pieces, reassemble and then a fit a small pipe to the outlet and lead to the outside of the boat. It should slope down to the outlet. It will now 'dribble' a stream of water when the engine is running, but will still act as an antisyphon valve when required. You can also lead it to the cockpit so it dribbles down a drain with the advantage you can easily see it without looking over the transom.

 

[Tranona]

Just cleaning it may stop the dribble. Rather than removing the valve and leading overboard, which is not always convenient to arrange, just lead the pipe to an overflow bottle which you can empty when full. Alternatively as in in my Volvo installation the dribble pipe goes to the water trap/silencer, but like the overboard solution is not always easy to arrange..

 

[VicS]

Just cleaning it may stop the dribble. Rather than removing the valve and leading overboard, which is not always convenient to arrange, just lead the pipe to an overflow bottle which you can empty when full. Alternatively as in in my Volvo installation the dribble pipe goes to the water trap/silencer, but like the overboard solution is not always easy to arrange..

If it goes to a bottle to catch what leaks dont put the bottle down below the water line or it may create its own syphon. It might also prevent it acting as a syphon release for the engine cooling system

 

[Robin]

We have a shower drain sump box mounted in the bilge into which the condensate run-off pipes from the two on board airconditioners drain as well as the fridge/freezer box drain and the calorifier overflow pipe from the expansion valve. When the water in this box reaches a predetermined level. it is automatically pumped overboard by a small built in Rule pump mounted in the box Prior to fitting this collection sump box we were low tech with 1 litre tonic bottles collecting at the end of each individual drain tube. Prior to that again, we worried about possible leaking keel bolts (especially after reading all the gloom and doom on here about Beneteau keel bolts) or we blamed propshaft and rudder seals

 

[Kwik Decision]

Thanks for the responses. I'm going to take it off, and have a good look / try and get it apart next time I'm on the boat - just removing the top does not get to any serviceable parts, although you can check to make sure the valve moves freely (it does). Piping the bleed line overboard or to the cockpit drain will be difficult, and I'm not keen on the sending it into a bottle, as if the pipe end is in water, it will stop acting as a syphon breaker, so if I can't stop it leaking, I'll probably take out a mortgage or a new one.
Cheers

 

[rob2]

Andrew,

It wouldn't be too hard to arrange a bottle with the pipe ending just a tad above the neck so that should the bottle fill it still won't be underwater and will still break any siphon. In fact, if the piep ended within a larger tube which then led into the open bottle top, should the bottle fill, it will overflow without filling the intermediate tube which guides the flow into it. A new siphon bream may well sort the problem ut in the short term, but it is likely to recurr after a good few engine hours, so a bottle would be belt and braces.

If you're cleaning the existing valve, I'd suggest you strip it right down and soak all the components in vinegar overnight to get the deposits off - that might restore it to full working condition anyway.

Rob.

 

[dom]

As others have said a good cleanup followed by a squirt of Teflon spray might fix it. If, however, you do need a new valve I think Vetus will sell you one:

http://www.vetus-shop.com/vetus-anti-syphon-airvent-with-valve-13-32mm-p-517.html

 

[michael_w]

I've got one of these and it aways squirts a bit when the engine starts. The solution was to add a length of hose so it dribbles in to the bilge, rather than over the engine.

 

[Kwik Decision]

Thanks for all the replies, I've now fixed the problem by fitting a new valve in the syphon breaker as suggested by Dom.
By removing the top bit, you can get to the valve. My initial thoughts were it couldn't be removed, but it just pulls out (don't drop the O-ring).
Force 4 were able to order in a new valve, (they don't keep them in stock) with a few days notice. The cost is just shy of £14, which is outrageous for a tiny little valve, but far cheaper than buying a new syphon break.
It was tested yesterday, when we motored for an hour with no water in the bilge.

 

[Martin&Rene]

In the Vetus manual that came with my boat, it says
"In the case of installation 1, a small amount of water will pour out of the outlet while the engine is running."

Installation 1 shows an engine exhaust. I think it is just because the pressure is pulsing all the time. The water on my boat runs into a small sump and I use a small 12v Whale submersible pump to pump it into a bottle every few days.

 

[LittleSister]

The valve in the Vetus fitting can get stuck by salt crystals. A good rinse through with fresh water may solve the problem.

 

[sailorman]

The valve in the Vetus fitting can get stuck by salt crystals. A good rinse through with fresh water may solve the problem.

a serious flaw in the design imo

 

[LittleSister]

The valve in the Vetus fitting can get stuck by salt crystals. A good rinse through with fresh water may solve the problem.

a serious flaw in the design imo

I don't see requiring occasional maintenance as a design flaw. I do see failing to mention the need for it in the product information as a serious omission.

 

[sailorman]

I don't see requiring occasional maintenance as a design flaw. I do see failing to mention the need for it in the product information as a serious omission.

if it fails to work so might your engine, once is enough engine kaput. i made my own & it piddles into a cockpit drain

 

[charles_reed]

After 12 years of struggling with my 25 year-old anti-siphon I've now bought a replacement from ASAP for £16.90.
The old one has been regularly stripped and rebuilt every couple of years, soaked in suphamic acid, re-assembled with new seals and O-rings, silicon and loving care but still starts leaking whenever the raw-water impeller (or pump) are replaced. On my case the bronze compression spring is exhausted and no careful stretching will get it back to full strength - additionally the knife edge round the valve is worn.
Vetus prices are extortionate and I would recommend a complete break and a new unit.
PS Don't put a pipe on the top nipple - it's only meant to be a breather and you need ample warning if it's ever leaking water.
PSS The problem might not be in the U-siphon break - it might well be excess back-pressure from a partially blocked injection elbow.
Clearing that is a necessary adjunct to dealing with the leak.