Water pulsing

Jaws

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Sep 26, 2008
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Opinions and cures please folks :)

If a tap is turned on fully the flow is perfect and has good pressure..

BUT !

Smaller flows ( such as through the waterpure system ) and it pulses..

I have a feeling I have read somewhere that it is possible to adjust the pump ?
 
Jan 8, 2014
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You can install a shurflo accumulator after the pump which smoothes the water floand stops the pressure switch machine gunning. I believe that CAK tanks sell them, I hope this helps
 

old-mo

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If it`s a "Sureflow".... there is a little black knob by or on the pump, John..

I had mine adjusted a few weeks ago when I had it serviced, and that is what the guy told me.. (y)
 
Apr 9, 2013
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A typical motorhome pump with probably look like this. http://www.shurflo.com/rv-products/rv-pumps/classic-series-water-pumps/shurflo-classic-pump/default.html

The black box on the front end of the pump is the pressure switch and I think that the central screw is used to adjust the pressure at which the pump switches on. A link to installation instructions is also on that page which should provide more data.

If your system has a small pressure vessel to dampen pressure fluctuations it may be that it needs recharging with air.
 
OP
Jaws

Jaws

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Yup, just been and checked it and it is a shureflo.. the ubiquitous 2095 in fact ( just could not remember ! )
I will try adjusting it first and if that fails I will strip it as I have just remembered something else.
The last one I had I had to strip as one of diaphragms was leaking by due to a bit of crap stuck somewhere..
And if that fails then I will look at an accumulator but with limited space and the way the pipes are run that aint gonna be easy !

Thanks for the inputs folk.... appreciate it (y)
 
Apr 9, 2013
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I wouldn't rush into stripping the pump. It doesn't sound like anything is wrong with it. Pressure switch or accumulator problem I would say.

Tim
 
OP
Jaws

Jaws

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Lot easier to strip and be sure than spend £50 on an accumulator ! ( mind you.. All they are is a plastic tube with a very low pressure bladder in them ! Could proly knock one up (y);) )
 
Apr 9, 2013
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But you say it's pulsing on low flow. That does NOT sound like a pump problem. It's a pump control issue caused by a low compliance system and a perhaps over sensitive pressure switch.

Why mess with the pump innards? If your accumulator has an air valve on the end poke it with a matchstick and see if water comes out. If it does, this means the diaphragm has failed. Even if the diaphragm has failed, if it it is positioned with the valve uppermost, topping it up with air will restore the damping. You will have to top it up periodically but that's no big deal.
 

scotjimland

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Jul 25, 2007
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Agree with Tim..

the pump pressure switch is set too low for the restricted flow of the filter..

open the waterpure system tap, increase pump pressure cut out set point by screwing the pressure adjusting screw clockwise.. try 1/4 turn at a time until it stops cutting in and out.. then close tap to ensure the pump stops. You may have to back off a tad if the pump either doesn't stop.. or takes too long to stop. .

An accumulator reduces surging in small systems, but the pump will still cut in and out unless the switch is set correctly.
 
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Jaws

Jaws

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Sep 26, 2008
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Yup, will be having an adjust a little later today .. Will have to remove the pump from its location to get at the adjuster so not quite a 2 minute job but easy enough (y)

There is no accumulator fitted.. in fact according to shureflo the 2095 should not need one, so hopefully the adjustment will work just fine :)
 
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Jaws

Jaws

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Sep 26, 2008
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Annnnnnddddddd. We are good to go (y)

Not exactly a 1/4 turn... More like 3 complete turns in..:eek:
And,,,,,, some muppet had removed the original fixing screws and replaced them with ones too short... Being too short they had left out the spreader spacers from the rubber grommets so the short screws would sink in !
Screws replaced but will have to find. Nice bit of ally tube to make up new spacers... Just used largish washers and left the screws a little loose for the time being.
But bottom line is, except for the tap(s) being set on the tiniest of flows, the pulsing has now gone.. As a bonus, the toilet flush pressure is now also what it should be !

Thanks to one and all for your input and help..(y)(y)
 
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