Nuevo water pump problem

The flow rate on our pump has reduced so much that it now only trickles out of the tap. Also the pump now refuses to stop when the tap is closed and despite trying to adjust the microswitch it has made no difference and the only way to stop the pump is on the Sargent panel.
In my 2011 Nuevo II EK the water pump is a submersible one actually in the tank and is the original so I assume it is reaching the end of its life.
What I would prefer is to have the pump in the tank removed and replaced with an onboard pump at the back of the wardrobe. I am wondering if the new Whale Watermaster FP0814 pump would be suitable? Has anyone used this pump and am I right in assuming there would be no need for the existing Whale microswitch assembly.
This is a link to the Whale pump
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MM,
I think this was discussed quite recently, with one of the members leaving the defunct submersible in place as a 'foot valve'. As I recall the alternative was to have to drop the tank to change the pump. If this is your problem, there has also been a recent thread re: fitting an inspection hatch to the bottom of your tank.

After all this time, I have still not managed to work out how to use the site search engine

No doubt one of the other less senile members will point you in the right direction.  

Derek

I've looked into doing exactly what you suggest Moggy, but unfortunately it isn't easy.

I don't know all the details but Mark Burdett (A/S Service Dept) says the Whale system (which uses an external pump dropped into a container for filling) is very complicated and is built into the main wiring loom, so it's not simply a case of disconnecting one pump and fitting another. On top of that you have to drop the tank to remove the submersible pump and replace it with a pickup tube - and it seems that dropping the tank is by no means straightforward.

I shall be delighted if anyone can prove me wrong, since I would also much prefer a diaphragm pump mounted on the wardrobe wall, where you can get at it and give it a clout when it needs one!!

I'm afraid this is another reason why I think it's a daft system. Fine while it works properly, but a real pain in the backside when it goes wrong. (By "backside", I mean the wallet of course! )

I don't quite understand why a diaphragm pump can't be connected to the circuit presently used for the submersible?? It would seem logical to disconnect the one and connect the other onto the same wires and water pipes - or am I being too simplistic?

I wonder if Peter #1 will know? He's pretty hot on the electricals.

Dave


P.S. Your link to the pump didn't work.

Try this one perhaps? Looks identical to  yours, but it seems to work??

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Dave,
Are you sure that you and Mark were not at cross purposes?
I agree that the wiring is complex but, although both the internal pump and the external pump are controlled via the Sargent panel they are different circuits. IMHO it should be possible to pick up the power feeds for the tank submersible pump and to run those to a different location to feed a diaphragm pump. The pump that you don't like is purely to fill the tank. It has nothing to do with the on board water systems. I am farly sure that the duff pump could be used as the pickup from the tank but only if it is not blocked and has a reasonably free flow through it.
Failure of the pump that is in the tank has NOTHING TO DO with the Whale filling system.

I have also often wondered whether it would be difficult to install a separate pump in line with the on board water system. I could pick up the wiring going to the pump in the tank and connect to an external pump which I could locate easily alongside the tank underneath and simply ignore the pump in the tank. Perhaps the new pump could simply be connected anywhere 'in line' of the water pipe leaving the tank.
On another note I have a friend with an A/S who has replaced the pump in the tank. Briefly what he did was unscrew the inspection hatch on the bottom of the tank and felt around for the pump which he says is just lose in the tank. He located the wire entering the tank near the top and removed  it. Attached a piece of string as a draw string and pulled the pump and string out through the inspection hatch. He then attached the wire/pipe of a new pump to the string and pulled it back out and left the pump lose again in the tank. Presumably  connected the water pipe to the new pump Bit of sealer around the wire  and hole. Re connected where they were cut. Sounds relatively easy but then I did not actually do it. (He did not have to remove the tank)
 I have thought about installing a 'spare' pump in the tank with wires/pipe protruding through a hole at the top and sealed and leaving the them lose adjacent to the existing connections so that in the event of a failure all I have to do is get under the van and connect the  wire and pipe from the new pump. Can anyone see any problems in doing that, submersible pumps seem to be relatively cheap.

inspiredron wrote:Dave,
Are you sure that you and Mark were not at cross purposes?
I agree that the wiring is complex but, although both the internal pump and the external pump are controlled via the Sargent panel they are different circuits. IMHO it should be possible to pick up the power feeds for the tank submersible pump and to run those to a different location to feed a diaphragm pump. The pump that you don't like is purely to fill the tank. It has nothing to do with the on board water systems. I am farly sure that the duff pump could be used as the pickup from the tank but only if it is not blocked and has a reasonably free flow through it.
Failure of the pump that is in the tank has NOTHING TO DO with the Whale filling system.  

Hi Ron

I can only repeat what I was told by Mark.

I don't think we were at cross purposes as my question to him was, "Can you remove the inboard pump and replace it with a diaphragm pump on the wardrobe wall?" so he wouldn't have misunderstood that.

As I understood it, the circuitry for the two pumps is interlinked, and controlled by two pressure switches - which also influence each other. There are also relays and other factors to take into account, and it appears our mutual opinion that, " . . . it should be possible to pick up the power feeds for the tank submersible pump and to run those to a different location to feed a diaphragm pump." doesn't work in practice.

In fact Mark said, "The lads have done one and they don't want to do another. It was a heck of a job!!"

I also suggested that a duff pump could be used as a pickup, but he didn't think that would work. I can't help thinking he's wrong there, since I'm fairly sure the water would flow past the impeller easily enough.

Assuming all the above is more or less accurate, it seems that a failure of the inboard tank pump has everything to do with the Whale filling system - if you want to change it for a diaphragm pump.

That's what is vexing me, since I wanted to change the inboard pump for a diaphragm model before the submersible packs up - on the first day of a three week holiday in France!!!! If the pump is screwed to the wall I can give it a smack if it needs one, and I can carry a spare and replace it myself without much trouble. If (when) the submersible goes wrong we shall be deep in the merde!!!

Still hoping somebody knows for sure.

Dave

P.S. Our water tank has no inspection hatch, so the method Chudders suggests is no good either!

chudders wrote: I have thought about installing a 'spare' pump in the tank with wires/pipe protruding through a hole at the top and sealed and leaving the them lose adjacent to the existing connections so that in the event of a failure all I have to do is get under the van and connect the  wire and pipe from the new pump. Can anyone see any problems in doing that, submersible pumps seem to be relatively cheap.

That sounds like a plan Chudders. I can see no reason why that should present any problem at all - except to me (sob!)

I haven't got an inspection hatch in the bottom of the water tank.

Good idea though, and so simple.

Dave

I've had a look under our 2014 Broadway and it has a inspection hatch fitted, so I'm going to get a spare pump before we leave for our annual  Benidorm trip in October.

John.

The 'Whale system' is actually two completely independent Whale systems.

The fresh water filling system consists of an external pump or water main connected hose that plug into a bespoke connector on the side of the van.  The connector consists of a water input, electrical connections for the external pump and a pressure switch.  Also in the water circuit is a solenoid valve to control the flow of water into the van (that has an integral filter) and a float switch in the freshwater tank.  For the solenoid valve to open and allow water in there has to be pressure on the switch from mains or pumped water and the float switch has to be operated (by the tank not being full).

The water distribution system consists of an impeller pump (exactly the same as the external filler pump) connected to the water pickup located in the fresh water tank and a pressure switch assembly located in the water distribution pipework.  When the pressure in the water system reduces because a tap is turned on, the pressure switch allows a feed to the pump in the tank.  When the tap is closed and the pressure builds up and the pump is switched off.  The most common cause of pump failure is if the pump circuit is switched on when the water system is empty - the pump will run continuously without the cooling effect of water flow till it burns out.

The Shureflow type diaphragm pump has its own integral pressure switch.  One could be fitted anywhere in the pipework between the tank and the split between hot and cold water systems and there is definitely a thread on this forum describing how it was done for one particular type of van.  As long as the impeller pump in the tank has not failed so as to impeded water flow, there is no reason why it can't be left in place as the water pickup.  The electrical feed for the diaphragm pump could be rewired from the pressure switch and still controlled by the Sargent 'internal pump' switch or a separate fused and switched feed could be installed connected to the leisure battery.

If I find the other thread I will add a link

Many thanks Peter. (Confidence clearly justified )

This is very reassuring - "The Shureflow type diaphragm pump has its own integral pressure switch.  One could be fitted anywhere in the pipework between the tank and the split between hot and cold water systems and there is definitely a thread on this forum describing how it was done for one particular type of van.  As long as the impeller pump in the tank has not failed so as to impeded water flow, there is no reason why it can't be left in place as the water pickup.  The electrical feed for the diaphragm pump could be rewired from the pressure switch and still controlled by the Sargent 'internal pump' switch or a separate fused and switched feed could be installed connected to the leisure battery." and exactly what I wanted to hear.

I would want to leave it to be controlled by the Sargent unit which makes it a fairly simple job - so it sounds like the answer to all my concerns, and those of several others including Moggy, the OP.

Many thanks. The beers are on me if we are ever fortunate enough to meet!

Dave

HI Peter thanks for a very clear explanation. I have found the original post from 2 yrs ago when I was considering changing the pump which I now intend to do.
I note that you say I can simply pick up the power for the Shurflo pump from the pressure switch once removed. This would be easier than pulling back the existing wiring to the pump in the tank. Would I simply have to tape up these wires to the tank pump or would they need to be joined together?
Link to the old post below 

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I would leave the redundant wires to the pump in the tank in place but disconnected in case it was ever decided to revert. I would tape the ends for tidiness and add a label to confirm what they are for future reference.

Thank you Peter for restoring my confidence in my own common sense!  From the way things work I had assumed that the two circuits were independent but was put of the scent by Mark's difficulties.  It seems to me that, if it was easier to pick up the wiring for the Shurflow from the existing impeller pump feeds, then that woudl be no problem as long as the wires to the existing pressure switch (in the bed locker on my Lancashire) were removed and joined or the pressure switch itself was adjusted so as to never switch off.
I am a bit surprised at the apparent concern that impeller pumps will fail.  I only ever had one problem on my Hymer when the pumped water pipe came off the pump stub while Judy was in the shower and fully soaped.  She was not amused at having to be rinsed with cold water! Luckily that van had the fresh tank in a bed locker and there was a big cap on top.  Even then it took a bit of effort to find and correct the problem. That pump lasted 11 years till we changed vans without any problems and the one on our 1979 caravan (also a Whale) lasted 20 years. I reckon that sort of life is normal PROVIDED that you don't cane the pump by running it dry or maybe by using it to empty your 100 litre tank or, worse, letting it freeze with water in it.  That is why I drain down my loo flush tank by pulling out the plug, rather than flushing the whole lot into the cassette. These pumps are unlikely to fail in normal use. But I am glad that I have a hatch because if it does go then, whether I am at home or abroad I can get a new submersible pump and a tube of silicone sealant for the wires from any caravan or motorhome dealer and fit it.

Peter Brown wrote:I would leave the redundant wires to the pump in the tank in place but disconnected in case it was ever decided to revert.  I would tape the ends for tidiness and add a label to confirm what they are for future reference.

Thanks for reply Peter but could you just clarify should the wires to the tank pump be taped up individually or joined together? Also the wires to the pressure switch in the wardrobe I assume one is positive and one negative and I take it they are powered when the pump control on the Sargent panel is switched on so I can test polarity?
Sorry to sound a bit thick but electrics is not my best thing!

moggyminor1966 wrote:

Peter Brown wrote:I would leave the redundant wires to the pump in the tank in place but disconnected in case it was ever decided to revert.  I would tape the ends for tidiness and add a label to confirm what they are for future reference.

Thanks for reply Peter but could you just clarify should the wires to the tank pump be taped up individually or joined together? Also the wires to the pressure switch in the wardrobe I assume one is positive and one negative and I take it they are powered when the pump control on the Sargent panel is switched on so I can test polarity?
Sorry to sound a bit thick but electrics is not my best thing!

What Moggy said - specially the last bit!!

If we are planning to use the wires supplying the pressure switch for connecting a new pump, would it be necessary to grovel under the van to cut and tape the wires to the tank pump?

Logic suggests (though electrical theory may not agree! ) that if the 12 volt power to the tank pump is disconnected at the pressure switch, that will be sufficient. There would be no need to disconnect at or near the tank as well????

Thanks again

Dave

Hi Gromit
Thanks for your input I just want to make sure I know what I am doing before I start!
In the link I gave stevepluschris joined the 2 wires from the pressure switch and pulled back the wires from the tank pump to connect to the new Shurflo pump.
Peter's method would be simpler and the way I see it I remove the existing pressure switch and connect the 2 wires from this to the new Shurflo pump. Then on my Nuevo the 2 wires from the tank pump come out of the top of the tank then at the back of the tank they are joined with spade connectors to the wiring loom running back through the wardrobe floor. So I can simply disconnect the spade connectors but do I connect them together or not?
Hopefully Peter will be on the scene soon to clarify.

moggyminor1966 wrote:So I can simply disconnect the spade connectors but do I connect them together or not?

Don't forget I haven't got one of these systems on my drive to check out so the advice is purely theoretical.

When you disconnect the pump at the spade connectors, the wires to the tank will be dead and can just be tidily set aside. There is potential for the connectors left in the loom to become live at 12v so they should be insulated just in case.

I would just add to what Peter has said that you should NOT join the wires that come from the old pump together but insulate them separately. The reason for that is that if the wires are joined and if the water flow tries to turn the impeller in the dead pump then it may try to act as a dynamo and joining th ewires will complete the circuit.  No danger but theoretically it will cause drag on the impeller and that may slow the flow of water through the dead pump.  Now that is purely theoretical and the drag may not be significant but why chance it?
My Prius uses a similar principle for initial braking where energy is put into its battery and exerts a braking force before th ebrake pads even think about working.

Thanks for that Inspiredon.

Hmmmmmmmmm???

Can't stop now Moggy, but I'll be back later with a further query about joining the wires.

Wish I was better with electrickery!!

Dave

Thinking about the connections to the existing submersible pump, and Peter's more convenient method:--

If it's a straightforward circuit (some hope!!) with the pressure switch acting as a simple switch in the live feed to the pump, when it (the pump) is disconnected the wires in the loom which lead to it would have to be joined together - I think! (Always bearing in mind my singular electrical incompetence! )

(The wires coming from the submersible are redundant, but bear in mind the point made by Ron, above.)

If the existing pressure switch is removed or bypassed and its wires connected to a new diaphragm pump, it should work. The pressure switch integrated into the new pump should control the on/off by making and breaking the circuit as before, and it will still be controlled by the Sargent panel.

I think???



Dave

Hi Gromit
What you say in theory does make sense but who knows. I think when I get round to fitting the new pump it will be a case of try it and see!