Duetto water pump

The water pump in our Duetto has always operated intermittently when no water has been demanded via any of the taps.  It's worse when the tank isn't brim full.  We've managed simply by switching off the power on the panel.  Obviously the system pressure is falling for some reason but there don't seem to be any obvious leaks. 

The pump is a Surflo 208-110-41.  As a reward for allowing me to buy a new radio control transmitter for my model aeroplanes my wife is insisting I cure the pump problem :)  I think I'm going to have to replace the pump but this model is no longer available.  Would this one be a suitable replacement?

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thanks in anticipation

Geoff

Whoa there!!!

Let's not be spending any money until the problem is resolved as being a pump problem!

The pumps stops on activation of a "pressure switch". When the pressure gets high then the pumps stops and then re-starts when the pressure falls.

Intermittent running of the pump at night can be due to (in order of probability):

1. Hot water contracting.

2. A non-return valve leaking and releasing discharge pressure.

3. A very small leak in the system.

4. A leak in the bladder of an expansion tank.

IT IS ALMOST NEVER DOWN TO A PROBLEM THAT NEEDS A NEW PUMP! 

Hope this helps. 

Best regards,
 

Thanks Dutto.  I must admit that thought had crossed my mind as well.  It's just that I can't see any evidence of leaks anywhere and we very rarely use the hot water system except when we use the shower (we DO shower but often using site facilities :) ).  Plus, the thought of pulling the whole van apart looking for leaks in inaccessible places horrifies me more than a simple pump replacement.

It doesn't help that it doesn't bother me much. I don't mind switching off the power to the pump when we're not using it.  My wife thinks differently however ... and I wanted that new toy.

Geoff

You may find this thread re-assuring  ........


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Geoff,

PS I forgot to mention THE most obvious cause of intermittent pump activation; a dripping tap. (Especially the one that is in the shower room and therefore can't be seen or heard.)

Just two thoughts:

1) What will you do when you find that a new pump hasn't cured the problem?  

2) It takes about fifteen minutes to change out the pump diaphragm (the only pump related cause) and costs about 5% compared to a new pump!

Finally, my pump is coming up fifteen years old so when you get your new toy I can easily find a use for your old one!  

Best regards,
 
Ian

Go to agree there - in all the vans I've owned I've never had a pump fail. I did a diaphragm change on the pump in my last van, but it was unneccesary (i.e. it didn't cure the problem I thought I had!).

One further cause of intermittent running on is that when you drive the van with an only partially full tank, occasional hard cornering can expose the outlet pipe, allowing small amounts of air into it. This then gets pumped into the system, and results in small airlocks. They eventually work their way out (usually), but while in there the compressible air is much more prone to expanding/contracting as things heat up and cool down, and this can cause small pressure drops which make the pump run for a short while.

If it's otherwise working Ok, I'd just leave it (and try to remember to turn it off at night...)

Had a similar problem recently in my Exectutive. The pump kept on churning over ever 5 or 10 minutes or so with out warning or any just cause. Or so we thought !
Turned out to be the dump valve, which is located under the side sofa, had the awning poles "resting" on top of the yellow handle.

Although not enough pressure to open the valve and dump water to the ground, it was enough to brake the pressurised system, causing the pump to re-charge itself .

We now have a plastic box inverted over the dump valve, to stop anything else being in contact with the valve.

It might be worth a quick look to make sure your valve is ok,  Geoff?

Nice one Dago! 

Always like it when a bit of detective work produces results!! Well done! 

Best regards,