Water pump intermittent failure (1 Viewer)

[Bonglewagon]

Hi all,
I have a Globecar Roadscout R. If I turn on a tap I may get some water for a few seconds and then a high pitched whine develops and the water supply ceases. Or I get no water, just the whine.

It is possible that I may have damaged the pump when showering. The Roadscout shower has a control on top of the shower head in addition to the main tap over the bathroom washbasin (which activates the pump). To shower you turn on the basin tap and then use the control on the shower head. After showering you must make sure you turn off the basin tap to shut down the pump. I forgot to do this and was only alerted to the problem when an ever increasing high pitched whine developed (the pump was trying to pump but could not expel water as the shower head control was shut). The next day the pump fuse was blown (and I replaced it).

So now the pump may work briefly (or not at all) before I get a high pitched whine and no water.

My questions are:
1. Has any one had a similar experience? And if so how did they fix it?
2. Where is the water pump on the Globecar Roadscout?

Any advice much appreciated.

 

[Lenny HB]

If it is a submersible pump have a look at the pump body to see if there are any signs of overheating, a lumpy bit that looks like it may have overheated. If so I would replace it before it fails totally.
Not quite the same but I ran a Reich Tandem pump dry for about 2 hours, several months later it started working intermittently then finally packed up.

 

[denisejoe]

Sounds like the motor is spinning but the impeller has detached itself

Joe

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[Reallyretired]

Its possible that the back pressure has caused the impeller to become loose if it is a submersible pump. Probably cannot be repaired and will need replacement. Seems a rather poorly designed system, with a pressurised system the problem would not arise.
I can't understand why manufacturers use these microswitch taps, they can't be any cheaper, more complicated to install, and are prone to failure.

 

[Lenny HB]

I can't understand why manufacturers use these microswitch taps, they can't be any cheaper, more complicated to install, and are prone to failure.

I would much rather have micro switches as if a pressure switch fails you are stuffed, if a microswitch fails it only effects one tap and you can still get water out of that tap by turning another tap just enough to trigger the switch. I always fit a relay in series with the pump to take the load off the micro switches.
The problem the OP has appears to be similar to using a trigger shower head with a micro switched tap, something you shouldn't really do.

 

[tonyidle]

The pumps aren't positive displacement so obstructing the flow with a shower head tap shouldn't cause a problem. A high pitched whine means that, as suggested already, the impeller has become detached or that there's no water for the pump to, er, pump.

And I'm with Lenny - pressure systems sound as though they should be more efficient but in 40 years of caravaning & MHing I've had a couple of microswitches fail and a couple of drop-in pumps. I've also replaced three diaphragm pumps (another pet hate) and two pressure switches. The big difference is that microswitches & especially drop-in pumps are cheap & available everywhere and anyway, as Lenny suggests, it's easy to work around problems. The relay is a must.

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[Bonglewagon]

Thank you all for the advice.

On inspection it seems I have a submersible pump, and I will follow up your suggestion that it is probably a fault with the impeller.
I will try to take the pump out and see what the make and model is and then install a replacement.

Regards

 

[TheCaller]

Our very similar Campscout definitely has a submersible pump. Accessible through the large red inspection cover on the tank top - which if done up tight enough not to leak if you have the tank full can be an absolute b***er to unscrew!

The other advantage of micro-switches is that if you have a pipe come loose, the pump doesn't immediately pump a full tank of water all over the inside of your motorhome! (If you are unlucky though, syphon action may achieve the same thing, only a bit slower & in silence. )

 

[Bonglewagon]

Latest update:
By visual inspection (peering through the red inspection cap on the water tank) the pump appears to be a LUX-PLUS with vented non-return-valve and filter:

www.comet-pumpen.de/en/products-rv/pumps/submersible-pumps/submersible-pumps-12-v/lux-lux-plus-auro.html

It's a German made pump and as the Globecar is made in Germany that makes sense I guess.

Can any one advise how to remove it? It looks as if the pump might be a push fit into the non-return-valve; but I can't shift it. It's very, very awkward trying to do this through the inspection cap on the top of the water tank. Do I require a special tool?

Also of interest. The rating of the pump is 4amp but Globecar fit a 3amp fuse in their electroblock controller???

Any suggestions on the pumps removal gratefully received.

Regards

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[berni109]

submersible pump on mine (adria not globecar) went and the length of pipe inside the tank was not long enough to lift the pump out so i cut the pipe got a nylon joint a length of pipe and a couple of stainless jubilee clips but i was already sure the pump was fubared.

 

[Lenny HB]

The one way valve is a tight push fit on the pump often a one shot device, pumps are sold with the valve on. Normally where water connection is there us a plastic circlip you pull out to release the fitting.

 

[Bonglewagon]

Thanks for the input Guys,

Berni109: I hadn't thought of cutting the pipe. It's a good final solution if I can't find another way. I find it hard to believe that they have designed a system that is so hard to service.

Lenny HB: Can you say where the plastic circlip is positioned?

Thanks

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