Unidentified hose in stern of B33 Cruiser 2006

[jfloyer]

Hi all.
I am a new B33C owner and have just been going over the boat in detail to familiarise myself with electrics, plumbing etc...
When I opened the hatch at the back of the lazarette I was a bit confused to find a heavily-lagged PVC hose which connects at one end to the outlet on the starboard side of the transom (see images) and at the other end has a metal fitting which is not connected to anything.
Can anyone please help me to identify what this is meant to be doing? The boat has a Webasto heater but I understand that this is electric and has no need for plumbing.
Many thanks.
Jim.

[Odysseus]

Looks like a heater exhaust for a Webasto or Eberspatcher. 

Odysseus
Bav 38

[Ricd]

The heater is diesel fuelled hot air system, not electric.  If it was the heater exhaust the skin fitting would be SS and not plastic as per the one on your transom., which would melt.
Is that a copper pipe?
Might be a drain for if the calorifier over pressures? 
No idea really..sorry

[jfloyer]

It's a start. Thank you both. I will get back in there later in the week to investigate further.

[Salty]

Going on line I see that webasto have had an electrically powered heater that appears to have been developed and first marketed in 2012 or thereabouts. I'm not familiar with such systems, but from what I've read about them, they heat water, but thereafter I don't know what is done with the hot water, maybe to some sort of radiator system with electric blowers to spread the warmth around.
Looking at the pipe you show in one of your pictures along with your description I would imagine that this is an overflow or excess pressure relief system that would allow excess hot water/pressure to be exhausted safely to atmosphere. Perhaps there is a fitting on your heater to which the hose should be connected, so perhaps a close inspection of the heater is needed, and preferably while it is not actually running.
If your heater is diesel powered, then you would have a stainless steel exhaust system of about the same size as the pipe you show. On my eberspacher heater this is a 22mm diameter coil wound tube to allow flexibility, but which is lagged and further protected by a 55mm diameter aluminium flexible tube. You need to check and be certain whether yours is electrically or diesel powered.

[jfloyer]

Thanks Salty. I have found the installation guide which I will study at leisure. The model is one of the Airtops although I need to identify which one (but it is definitely a diesel-burner as you say).
I will post once i have investigated in a couple of days.

https://www.butlertechnik.com/downloads/Webasto_Install_Instructions_Marine_heating_systems.pdf

[Ricd]

Could it be for the combustion air intake for the heater?

[Salty]

I don't think your loose ended pipe would be for the combustion air intake, there would be no great need for lagging around such intake other than perhaps to quieten the air flow into the heater. You mentioned in your initial posting that it is a pvc pipe, but are you sure, because if it was the exhaust from your heater then PVC wouldn't last more than a few minutes before it melted? It may be that you have some PVC wrapped around outside of the lagging for other purposes specific for your boat and whatever that open ended pipe passes near to, but if that is the case you need to investigate more closely what the innermost pipe is made from. If it is a coil wound stainless steel tube, then it's odds on to be the combustion exhaust, and if that is the case DO NOT RUN YOUR HEATER until it has been reconnected. Also I would strongly recommend that you install a CARBON MONOXIDE detector within the living spaces in your boat, because having recently replaced the exhaust hose on my heater I can assure you that stainless hose does not last forever.

[mikeiso1192]

Here is my take on this.
Picture 1 is plastic and low down on the transom and I suspect that it is exit for water from the bilge pump.
Picture 3 shows the lagged pipe exiting the transom higher up adjacent to the backstay reinforcement plate (not visible in Pic 1) and I rather suspect that this pipe exit will be s steel. I would suggest then that this would have been the exhaust for Eberspatcher/Webasto diesel heater.
Not hat I have anthing to compare on my boat - don't need heating in Greece - well not in the summer!
Mike

[Ricd]

I still think it might be the air intake or alternatively the bilge exit.  The lagging looks like it is intended to protect the hose from another hot surface. But I am sure we will eventually find out

[Baddox]

The plastic outlet is the same design and location as one of the bilge pump outlets in our boat.  The erberspatcher heater outlet is made of stainless steel as plastic would melt.  The heater outlet shouldn't be connected to the plastic outlet, the correct exhaust looks like this 

[jfloyer]

I hope to get down to the boat before the weekend to investigate further.
The bilge outlet is through the same place but on the port side.
In the meantime I don't need any heating (35ºc today) but it will be nice in winter - especially to remove a bit of humidity from the cabin.
I will report back. Thank you all for your help and comments.
Jim.

[Holger]

You should have two water outlets for the bilge pumps. One for the electrical bilge pump on starboard and one for the mechanical on portside. I attach a page from the manual of a 2006 B30. The bigger dark hoses running from the center to the stern are the hoses of the bilge pumps and these run to the outlets.

Perhaps you should check whether you have a heater at all. The loose pipe seems to be the exhaust for a heater but it should be attached to the heater otherwise it cannot serve its purpose because all fumes would stay inside the boat and either harm or kill you. The heater should usually sit above the hatch on starboard (that means on the other side than you took your pictures). When I look at your pictures I wonder whether a heater was installed and removed but the pipes are still there.

[Impavidus]

It looks to me like someone has tried to fit a portable generator in there and that's an exhaust pipe they have rigged. Its so home made! (So dangerous!)

Just taken another look, the outlet from the inside has fixings holding it in on the inside and a fixing plate next to it to take a fitting, (like the back stay) that too has 3 fixings through it? Are you sure your looking at the right height on the transom?
Normally the 33c has to transom outlets as supplied. One for the manual bilge pump and one for the electric. Both are plastic through holes and exit low down. If it is the heater exhaust it should be much higher and I would suggest you look higher up next to the back stay mounting point starboard side, outboard of the stay fixing point. BTW the all the diesel heaters now have a flexible stainless steel exhaust which is convoluted to flex as there is a minimum radius you can put in. These get very hot and must be propperly insulated, clipped or restrained every 300mm and the gasses must exit the boat through the correct fitting.     
 

Ant

[jfloyer]

Well I've had a very quick investigation armed with all the above info so I can rule out a couple of things - even though I don't have the definitive answer yet.
First off: there is a Webasto heater installed (I knew that because it was blowing cool air in the 'ventilate' mode). I have checked all the plumbing and it is correct. The coiled metal exhaust goes out through a stainless port on the port transom next to backstay chainplate and appears to be properly lagged. I attach images. The installation all looks pretty professional.

[jfloyer]

... forgot to show the heater exit on transom:

[jfloyer]

I can also report that both bilge pumps exit where they are supposed to: electric to port and manual to starboard.

[jfloyer]

So still wondering what the hell the mystery exhaust is from!!! As mikeiso1192 mentioned above it does indeed exit through a steel fitting next to the starboard backstay chainplate and although I haven't had time to rip open the lagging, it seems to be a flexible metal hose. Impavidus could have it right - it might have been a badly-installed generator although I see no signs of fuel line for it.