Water pump pulsing any suggestions

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SolentPhill

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The guy with the boat opposite me has an issue with his shower/ tap water, when he turns it on it doesn't come on and stay like mine it pulses, on for a fraction of a second then off, on off ect. He has an accumulator and as far as is is aware it's charged to 8 psi he had checked filters and they clean

Any suggestions where next?
 
no ideas from my own experience but a quick look through a plumbing site suggests these two potential causes may be worth looking at....

Presuming the shower has an external sensor... The sensors which are mounted externally to the pump becoming dislodged and moved out of their optimum position. these are black bullet shaped zipped to the pipes with a black wire to them. Try moving these a little and tighten the retaining clips when you have found the best position.

or

Should your shower pump start pulsing and delivering water to the shower in bursts, other taps in the house may be causing it to malfunction and there could be a problem with your pipework
 
A couple of things to check.

On the actual pump make sure it didn't sustain water damage over the winter causing a leak. Any leak on the pump will cause the pump to pulse. Also check for internal functioning and see that the pump works ok on its own.

On the accumulator make sure the pressure is set to a little under that of the pump working pressure and make sure the internal diaphragm is sound. There should be no water in the air side of the bottle (you may have to let quite a lot of the air out to check so make sure that it has a shreider valve on top.

Finally check for leaks on any the pump gauze filter if installed.

Henry :)
 
Drain all pressure from the system and then check accumulator, try at about 4-6 psi if in doubt remove and make sure that no water had got into the wrong side of the diaphragm, what sort of pump is it? Has it got the adjustable pressure switch?
 
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As Henry has said, the accumulator needs to be a couple of psi less than the psi that the pump is set at, some pumps can be adjusted though,the pressure is usually marked on side of the pump, a pulsing system is more likely than not down to the accumulator not being pressurised enough.
 
My system did exactly the same two years ago.

I took the pipe off the bottom tank takeoff.

Only a trickle of water came out.
something had got stuck in the tank outlet.

I poked a screwdriver in and an aquatab treatment foil wrapper came out along with several gallons of water, I put a wooden bung in to stem the flow while I used a dinghy foot pump to blow the rest of the pipe system through.

All was fine after that.
 
Could be failure in pressure switches. Normally in systems with accumulator the pressure switches come on at pressure X and go off at X+25%. That 25% band needs to be that wide. If one of the switches has failed so that the pump is being switched by only one of the pressure switches, or a setting has changed, that 25% band will be too small or zero and the pump will pulse
 
PCUK said:
Only one pressure switch on standard systems and that cuts the pump when pressure in the system has built up due to taps being closed.
Click to expand...
yeah but it still has different pressure points for opening and closing the circuit, and if that gap is small it will pulse. (I think!)
 
Try rewiring the pump and by pass the pressure switch side of the pump, make sure you have tap open at the time. On my boat this was simple as the wiring connections were bullets. If the pump runs then it proves its the pressure switch.
David
ps I'am not a sparks but was advise to try this method by one of the manufacturers
 
I would also suggest it could be the pressure switch. Depending on the setup and boat it will either be a separate unit (as per the previous link) or it could be built into the water pump. If the switch is built in it can usually be adjusted by a small screw at the base of the pump. To adjust, open one cold tap fully and the pump should run constantly with no switching on and off. While the tap is open slowly turn the screw on the base of the pump (very slowly) until the pump remains on. Then turn the tap off and the pump should run for around 4 seconds while the pressure is built up again within the system before going off.

If this fails, I would then check the pressure and condition of the accumulator tank.

Ian
 
The same pulsing issue on our boat was due to a partial obstruction in a flexible hose leading to the tap.
 
Ok an update on this, climbed in over the weekend and found that the pressure was down on the accumulator, I pumped it up to 41 as thats what the book says and the tap in the galley worked fine, the batheroom was still pulsing, took the cupboard door off and had a look at the under side of the taps and (I think and here is where you lot come in), the hose from the pump is a normal blue snap fit and it goes to a small say 10mm od flexible hose, I think this acts like a blockage as the hose is too small. but surely all Jeanneau models would do this? Also the accumulator did not hold the pressure it lost it within minutes, so I guess there is some sort of bladder, are they repairable or is it replacement?

Cheers all
 
The accumulator needs replacing. They aren't expensive. Not sure where you're based but Uxbridge Boat centre have a great range of all that sort of stuff and aren't expensive, narrow boat prices rather than coastal prices.

I suspected the accumulator was knackered internally. In terms of pressure to set at it,s the pump which determines that. The accumulator needs to be a little bit less than the pump.

Henry :)
 
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