Pressurised water system.

[[178529]]

On my new (to me anyway) boat there is a pressurised pump driven water system with a hot water tank that runs from the engine or shore power.

Now i've never had running water on a boat before, other than water tanks with hand operated pump mechanism,.

So first thing i did was empty the existing water as I think it had been there for a long time. The pump ran and both taps flowed out freely for ages until the tank presumably emptied.

Then I refilled the water tank and dropped in some water purification tablets.

When I tried to turn the pump and tap on again the oly thing that comes out from the cold tank is gurgling and spluttering. There doesn't appear to be any leaking of water as the bilges are dry. Is there any bleeding process to go through? Do electric pumps have to be primed in some way?

 

[coopec]

My very first thought is your pump self priming?

Do you know what type of pump it is? Can you see a brand name/model?

 

[pvb]

When I tried to turn the pump and tap on again the oly thing that comes out from the cold tank is gurgling and spluttering. There doesn't appear to be any leaking of water as the bilges are dry. Is there any bleeding process to go through? Do electric pumps have to be primed in some way?

If your pump isn't priming properly, you could perhaps encourage it by putting a hosepipe in the tank filler and letting it overflow at deck level. As the head of water will be greater, the pump should then prime.

 

[prv]

Just for the record, since you weren’t sure what to expect, a pressurised water system should just start working again when you refill the tank. There‘ll be a few seconds of spluttering and splashing from the tap as the air gets pushed through the system, but special bleeding actions shouldn’t be necessary in a properly-working system.

Pete

 

[vyv_cox]

If you can hear it clicking it is a positive displacement pump, a diaphragm type. It should self prime and most will lift water a metre or two. If it is not clicking it is either broken or a centrifugal type, which does need priming.

Sounds like you may not be waiting long enough if a diaphragm, which is most common type in a boat.

 

[prv]

Are centrifugal pumps common in water systems (ignoring the caravan style ones with microswitches in the taps)? Seems to me that they wouldn't build up enough pressure downstream to reliably trigger a sensor and stop. I've only ever come across diaphragm pumps (often the kind with multiple small diaphragms for less pulsing) but I certainly haven't done an exhaustive survey.

Pete

 

[vyv_cox]

Are centrifugal pumps common in water systems (ignoring the caravan style ones with microswitches in the taps)? Seems to me that they wouldn't build up enough pressure downstream to reliably trigger a sensor and stop. I've only ever come across diaphragm pumps (often the kind with multiple small diaphragms for less pulsing) but I certainly haven't done an exhaustive survey.

Pete

Perhaps not very common but they certainly exist. Whale make a clever pressure switch that allows a centrifugal pump to 'think' it is a diaphragm type. I had one on my transom shower.

 

[[178529]]

Quick update.

I've pulled a few things out and worked out a bit more whats going on. She's got two big water tanks, one on each side under the saloon berths. then a tap system that looks like it allows water to be pumped from one tank to the other and you can then choose to use water from either tank. I got the water running just by randomly switching the taps. I just need to work out what the various settings do now. Having said all that I usually just bring bottled water on board on previous boats.

 

[plumbob]

Interesting you say you have to pump water to the second tank. Would have thought that highly unlikely. If so that means you are only drawing water from 1 tank and would have to pump it back to the first tank.
I suspect you have a balance pipe between the two and your pump draws from the both due to this balance pipe. If not then I suggest you alter things soonest as you will have virtually stagnant water in one of your tanks. Hope this helps.

 

[NormanS]

If your boat has sails, make sure that the cross connection pipe is normally kept closed. ?

 

[neil1967]

Interesting you say you have to pump water to the second tank. Would have thought that highly unlikely. If so that means you are only drawing water from 1 tank and would have to pump it back to the first tank.
I suspect you have a balance pipe between the two and your pump draws from the both due to this balance pipe. If not then I suggest you alter things soonest as you will have virtually stagnant water in one of your tanks. Hope this helps.

We have two tanks and a balance pipe between them, but the take-off to the water pump comes from a T in the balance pipe and there are two vales in the balance pipe, one either side of the T, so you can select which tank to take the water from, and you open both to balance the tanks. The water filler only goes to one tank so you need to remember to open both valves when filling or only one tank gets filled.

 

[[178529]]

We have two tanks and a balance pipe between them, but the take-off to the water pump comes from a T in the balance pipe and there are two vales in the balance pipe, one either side of the T, so you can select which tank to take the water from, and you open both to balance the tanks. The water filler only goes to one tank so you need to remember to open both valves when filling or only one tank gets filled.

I think this is the same set up as mine.