Merry fisher 805 water collection

[Sulliy]

Hi

We've upgraded to a 805 and now managing to get onto it. But we are finding a collection of water in the bilge. I'll pump and dry it out, but water back tomorrow.
Tasted and it's fresh (shaft recently replaced so got the seals checked again).
Hasn't been raining. Any ideas where this water is coming from? Has to be from my fresh water tank - still working out the pipe routes - there does appear to be a tube running from a pump near water tank into bilge. Is this leaking?

Thanks for any info

 

[jamie langstone]

Check your hot water tank pressure valve is not leaking it normally vents off in to the bilge via a black pipe . The only other place I had a leak was
On a joint under the sink next to the water tank . Let’s us know how you get on.

 

[Montemar]

Our calorifier has a pressure valve which we are recommended to to check each month. I found this useful information three years after buying the boat. One turns a knurled knob on the valve which releases a small amount of water to show it can work. It then continued to drip but turning the knob several times eventually stopped it so I assume there was some kind of limescale causing the problem.

 

[Sulliy]

Thanks. I'll have a look.
Another pro today - went out. Engine bay bilge filled up whilst out with green murky water so this is definitely sea water. So could be water leaking from the engine (which I think is more likely) or is the 805 double skimmed and water seeping in somewhere else?

 

[Montemar]

Check water level for the engine.

 

[jamie langstone]

If its sea water it can only be either be one of these shaft seal leaking, rudder seal, hole in exhaust hose or leaking from a pipe that has sea water pumping in it .

 

[Jamie Dundee]

Thanks. I'll have a look.
Another pro today - went out. Engine bay bilge filled up whilst out with green murky water so this is definitely sea water. So could be water leaking from the engine (which I think is more likely) or is the 805 double skimmed and water seeping in somewhere else?

How green? Antifreeze green?

 

[Sulliy]

How green? Antifreeze green?

I say green, but it wasn't really. The sea looks green currently!
Water in bilge was just not clear.

 

[Montemar]

I looked in the bilges yesterday and had water under my calorifier. It could not have come from anywhere else. This means the pressure valve operated because of excess pressure which I very much doubt or it has started to leak/weep because the engine had been used for a 2 hour trip after doing nothing for months other than a few minutes running.

 

[thejonesey]

I had a problem with the stern gland seal on my MF805 after having a new one filled. Have you ‘burped’ it ie given it a squeeze to fill it with water? I also only got water coming through when we were moving but not on the berth.

 

[Sulliy]

I had a problem with the stern gland seal on my MF805 after having a new one filled. Have you ‘burped’ it ie given it a squeeze to fill it with water? I also only got water coming through when we were moving but not on the berth.

Yeah, checked with the marina engineers and they said they burped it once boat was launched.

Am going down there in a bit to see how much water is in there today - haven't checked for a few days and definitely been no rain!!

 

[Plum]

I looked in the bilges yesterday and had water under my calorifier. It could not have come from anywhere else. This means the pressure valve operated because of excess pressure which I very much doubt or it has started to leak/weep because the engine had been used for a 2 hour trip after doing nothing for months other than a few minutes running.

It is quite normal for the pressure valve in the calorifier to release some water to releive the buildup of pressure after an hour or more of engine running or when connected to the mains if you have an imersion heater. The heated water has to expand and go somewhere although if anyond on board opens a hot tap that releives the pressure. Many boatbuilders allow the leakoff to just go into the bilge. I havd fitted a 1 litre plastic bottle which i empty occasionally.

www.solocoastalsailing.co.uk

 

[Sulliy]

Found the source of leak in engine bay Coming from the sea water pump once engine running.
Also checked the gland and burped it, could hear some air coming out then bit of water , so hopefully that's sorted as well. Thanks for everyone's help and advice.

Two more questions, which may be contributing to it. I have a black pipe coming from the water heater into the bilge (in lazarette) and the valve seems to be in the off position (see pic). Is it meant to be off?

And where is the automatic bilge situated? Is it directly under the engine, which is why I can't see it?

Thanks everyone

 

[thejonesey]

Do you have an automatic bilge pump as mine did not come with one. Mine was fitted at the stern of the engine bay.

 

[Jamie Dundee]

Found the source of leak in engine bay Coming from the sea water pump once engine running.
Also checked the gland and burped it, could hear some air coming out then bit of water , so hopefully that's sorted as well. Thanks for everyone's help and advice.

Two more questions, which may be contributing to it. I have a black pipe coming from the water heater into the bilge (in lazarette) and the valve seems to be in the off position (see pic). Is it meant to be off?

And where is the automatic bilge situated? Is it directly under the engine, which is why I can't see it?

Thanks everyone

If the bilge pump set up is the same as the Antares it will be in the heads with a hose running to the bilge and a float switch in the lazarette.

 

[Montemar]

It is quite normal for the pressure valve in the calorifier to release some water to releive the buildup of pressure after an hour or more of engine running or when connected to the mains if you have an imersion heater. The heated water has to expand and go somewhere although if anyond on board opens a hot tap that releives the pressure. Many boatbuilders allow the leakoff to just go into the bilge. I havd fitted a 1 litre plastic bottle which i empty occasionally.

www.solocoastalsailing.co.uk

Thanks for your reply. Would not the pressure vessel in the cold water supply from the tank absorb a pressure increase? I estimate that there was a litre in the bilge which seems quite a lot. I shall go and work the valve a few times and see if that fixes it.

 

[Plum]

Thanks for your reply. Would not the pressure vessel in the cold water supply from the tank absorb a pressure increase? I estimate that there was a litre in the bilge which seems quite a lot. I shall go and work the valve a few times and see if that fixes it.

The pressure vessel after the fresh water pump is to smooth the flow. As the fresh water goes into the calorifier it passes through a one way valve put there to stop the build up of pressure from heating the water going back down the cold supply hose. Some systems have an additional pressure vessel after the calorifier to absorb the pressure due to heating. If you do not have that second one you are only reliant on maybe an air pocket in the calorifier if the hot outlet is not right at the top.

Www.solocoastalsailing.co.uk

 

[Montemar]

The pressure vessel after the fresh water pump is to smooth the flow. As the fresh water goes into the calorifier it passes through a one way valve put there to stop the build up of pressure from heating the water going back down the cold supply hose. Some systems have an additional pressure vessel after the calorifier to absorb the pressure due to heating. If you do not have that second one you are only reliant on maybe an air pocket in the calorifier if the hot outlet is not right at the top.
Thankyou, I did not know about the one way valve.