Winterised fresh water pressurised system not priming

MagicalArmchair

MagicalArmchair

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In the below post I asked what needed doing to winterise the fresh water system on my late fathers boat:

http://www.ybw.com/forums/showthread.php?415992-Winterising-pressurised-fresh-water-system

I emptied the tank and then drained down the calorifer and claimed it a job well done. A lovely young couple have bought the boat and are en route to their home port and they cannot get the system to work. They claim theyhave bled all the air from the calorifer, however the pump just runs and no water comes through.

What advice can I give them?
 
I will give it a go !

If the pump is working then it is either pumping air or water. If water, it is leaking and will be in the bilge. More likely the system as a whole needs bleeding.
Think I would turn the taps open and then keep the hose topping up at deck level to create a "head" of water so as to push the water out of the tank and into the pipes until it gets to the pump then it should sort itself out.
 
MagicalArmchair said:
In the below post I asked what needed doing to winterise the fresh water system on my late fathers boat:

http://www.ybw.com/forums/showthread.php?415992-Winterising-pressurised-fresh-water-system

I emptied the tank and then drained down the calorifer and claimed it a job well done. A lovely young couple have bought the boat and are en route to their home port and they cannot get the system to work. They claim theyhave bled all the air from the calorifer, however the pump just runs and no water comes through.

What advice can I give them?
Click to expand...

Pump suction filter blocked or more likely dirt in thr pump valves. Could be suction or discharge valves (or both)

Therefore strip, clean and rebuild pump
 
VicS said:
Pump suction filter blocked or more likely dirt in thr pump valves. Could be suction or discharge valves (or both)

Therefore strip, clean and rebuild pump
Click to expand...

Suggest, pump valves stuck open, as Vic suggests strip and rebuild - if it's a diaphragm pump running it for a few minutes won't cause much problem.

However, my unit takes about 90" to prime from empty, and it won't prime unless the tank is at least 1/2 full which means there is a head of water to fill the pump, at least one tap needs to be open. The acumulator takes time to fill, mine is only 1 litre, many are as much as 5 litre.
Perhaps the new owners haven't tried for long enough?
 
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They are at sea, so they have no opportunity to add water to the tank - I could advise them to open the taps fully and leave the pumps to run for ten minutes at a time? Failing that, VicS, take your approach of taking the pump off and stripping it down. I would be surprised if there was any dirt in the system as it always 'ran' very clean.
 
MagicalArmchair said:
They are at sea, so they have no opportunity to add water to the tank - I could advise them to open the taps fully and leave the pumps to run for ten minutes at a time? Failing that, VicS, take your approach of taking the pump off and stripping it down. I would be surprised if there was any dirt in the system as it always 'ran' very clean.
Click to expand...

Have they bothered to fill the tank with water - or do they expect, like a house, to have mains connected?
 
If there is water in the tank, and if the valve on the tank is open, you can obtain extra head by using a dinghy pump. This may well flush through the foreign body (am I allowed to say that?) which may be holding a pump valve open.

Wrap a rag around the dinghy pump hose, and stick it into the tank filler. Use another rag, or plug, to temporarily block the tank breather. Apply dinghy pump pressure gently. It's amazing what can be done with a dinghy pump.:D
 
What happened to me

First suggest they loosen / disconnect a hose from the inlet side of the pump and check there is a flow.
If there is then remove the pump and strip the pump end down. In my case it was apparent that over winter the pump had still held water and had frozen. No permanent damage but the valves had popped out of their holders. They are merely neoprene discs with a pimple on the back that push fits into the pump body. An hour spent saved the cost of a new pump.
If it's not working but makes a noise then nothing to lose checking this.
 
Open taps and run pump. Could take a good few minutes to prime but if there's water in the tanks, it'll happen. The gauges on our tanks have long stopped functioning so we only know we've run out of water when the pump free runs: the we switch over to the other tank and let it run with an open tap, typically takes two to three minutes to get the water flowing, as the air In the pipes has to be pumped through before the water arrives. Takes even longer if the hot water system has been drained, as that needs to fill before the system will be fully pressurised.
 
Just had this problem on my boat after draining down last year. ...... pump would not prime..... turn on cold tap and suck hard on the tap outlet...... system primed instantly and full flow of water......
 
MagicalArmchair said:
In the below post I asked what needed doing to winterise the fresh water system on my late fathers boat:

http://www.ybw.com/forums/showthread.php?415992-Winterising-pressurised-fresh-water-system

I emptied the tank and then drained down the calorifer and claimed it a job well done. A lovely young couple have bought the boat and are en route to their home port and they cannot get the system to work. They claim theyhave bled all the air from the calorifer, however the pump just runs and no water comes through.

What advice can I give them?
Click to expand...

Curiosity, did you hear if they found and solved the problem?
 
Mea culpa. I faced the same situation a couple of sesons ago. Turns out I had forgotten to reconnect the cold water pipe where I had disconnected it to drain the calorifier. Lots of water in the bilge!! Simple fix but I now leave a note to myself on the nav table to remind myself to do it at the start of the season.
 
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