spluttering water supply

Hi all, I have a 1992 VW T4 Trident and I'm having some trouble with my water supply. I am only getting a spluttering intermittent supply though the tap even though the noise from the pump is constant and sounds as it usually does. I have done what I normally do after a period of non use and sucked the living daylights out of it through the tap but to no avail. Any suggestions?

Cheers

Hi there,

May be:

o  System not properly primed.

o  Tank not full therefore air getting into system.

o  Loose pipe connection on suction allowing air into system. (I would go for this ....)

o  Cracked suction filter allowing air into system. (.... or this.)

o  Worn diaphragm needs replacing.

Hope this helps. 

Best regards,


PS

I am assuming that the pump stops when the tap is closed.  If not I go for worn diaphragm. 

Aha! forgot to mention that the pump doesnt stop when taps are shut! So it looks like the diaphragm needs replacing. Is this complicated or an easy job, we are away from the end of this week so need to fix quickly

Hi there,

It is usually quicker to get a new pump which will be available at most caravan/motorhome outlets; but they are eye-wateringly expensive!

Here's an outfit that supplies spares ....

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.... and new pumps if required.

I would still eliminate the other potential problems before deciding that a new diaphragm is needed 'cos they aren't cheap either!

Also, check that the pressure switch hasn't been set too high before you install a new pump or diaphragm.  (The last thing you need is to fit something new and the reason the original failed is still there!!)

Best regards,

Thank you so much for you info. In the interest of saving my wallet a minor cardiac arrest I set about checking out some of the rest of your checklist. Upshot is a found some less than tight jubilee clips and some other black nuts on the pump, hey presto all works!! Also took some advice from previous forums posts and loosened the bolts on the rubber mounts, now I've halved the noise my pump makes as well!

My only other question now is the location of this pressure switch and what sort of setting should it be at?

Again thanks a lot!

Booker wrote:............

My only other question now is the location of this pressure switch and what sort of setting should it be at?

.........

Hi there,

Great that things get fixed with only a bit of exploration and work!!   

Many modern pumps have an inbuilt (and sometimes non-adjustable) "on/off" pressure switch.  It you Google "[You must be registered and logged in to see this link.]" you will get a range of photographs and exploded views of a variety of Shurflo Pumps.  If your pump is a different make then do the same thing.  In most instances you should be able to find the one you have and work out whether or not it has an internal pressure switch.

If it doesn't then somewhere in the discharge piping from the pump (usually very close to the pump) there will be something that looks like this ....

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The "on/off" pressure is adjusted by the knurled knob.  The pressure should be set "as low as you can get away with" without the pump "chattering".  This will improve pump diaphragm life and reduce battery drain.

Hope this helps. 

Best regards,

if the pump is now working ok.then i work on the saying if it ain't broke don't mend it .have a good break G.

fisherman3 wrote:if the pump is now working ok.then i work on the saying if it ain't broke don't mend it .have a good break G.

Agreed ....    

.... but reducing the pressure will help pump diaphragm longevity and battery usage.

We don't use our pump to drive the shower so we can get by with a very low pressure setting.  Hopefully the pump will last forever!  

Best regards,

Hi Dutto ,
I've got the external pressure switch , the instructions say turn clockwise until the pump comes on then turn it back slightly until the pump goes off. 
Is that what you mean by reducing the pressure ?

Fredcool wrote:Hi Dutto ,
I've got the external pressure switch , the instructions say turn clockwise until the pump comes on then turn it back slightly until the pump goes off. 
Is that what you mean by reducing the pressure ?

Hi there,

As a general rule "Clockwise" = Higher Pressure and "Anti-Clockwise" = Lower Pressure so:

1.  From new the pressure switch is normally set at "Low" so the pump will start and then stop immediately as the pressure rises.

2.  Turning the knob "Clockwise" will ask for a higher pressure, the pump will start and then stop when the new pressure is reached.

3.  At this stage you need to check that you have sufficient pressure to do the things you want to do by checking the shower, sink etc.  If there is insufficient pressure then repeat stage 2.  (Don't be tempted to get the highest pressure possible.  It will shorten the life of the pump diaphragm.)

If the pump is set at a higher pressure than you need, turn the knob anti-clockwise and then open and close a tap.  The pressure will be released, the pump will start and then stop at the lower pressure.  Check that the pressure is what you want and then either repeat the performance or put the knob back to where it was.

The instructions to "turn the knob back slightly" is there for those people who screw the pressure switch in so far that the "Off" part of the switch is defeated and can't operate.  By the time this happens the pump will be putting up its maximum pressure and will be recycling the water internally to prevent blowing the head seal and/or the diaphragm.  The internal water recycling facility is there for very short-term use to prevent major damage.

Hope this helps. 

Best regards,

Ok , thanks Dutto , you should be writing the instruction manuals for Motorhome appliances ! Your reply makes more sense than the leaflet I've got.