Nuevo (2011) water pump

Sorry to be controversial but have had Whale submersibles fitted to caravans being thrown in and out of gas lockers /vibrated on roads during travel etc for 30 plus years without a single failure . I had a failure in our first A/s due to a specific issue where the impeller spun on the motor shaft without gripping . I feel many issues are to do with the installation of the pump. In our case it hung vertical and was well short of the bottom giving potential for airlocks on refilling tank and it never accessed the bottom 20 % of the tank. I replaced it with pump on bottom at 45 degrees and never had any airlock issues or refill problems  in 4 years of ownership. 
         Yes a diaphragm pump will cure the 'issue'   but water hammer at low flow rates is not simply the sound of an engine running! The fixed flow rate of water and pressure produced by a diaphragm pump  has to go somewhere whereas low flow rate and demand  in an impeller pump will eventually vent water back through the pump into the tank. Try putting your thumb over the pump outlet while running and you will see what I mean!  
     Through time this ''water hammer '  could affect push fit joints with catastrophic results and a sodden wet van with pipework and joints being vibrated . Worse still leaks go unnoticed until major damage is done .  A pressure dampener or accumulator will help in the system to smooth out the pressure pulses .  If your lucky it wont give any issues and you just live with the sound of pipes rattling as pulses fire along their length and lets face it pipe fixings are few and far between so plenty of movement available ...  Im afraid by changing the pump you may  just introduce other issues the original system was not designed for without further mods.  Its your van and I dont care either way but lets have balanced debate please. And no I dont work for Whale or have any interest .   

I've had both systems in my Nuevo and go with the Shurflo.  There are two meaning to pulsing.  A constrained flow rate due to a tap that isn't fully open will cause the water pressure to build up until the pressure switch turns the motor off. When the pressure drops the motor will come back on again.  This process happens for both the Whale and the Shurflo and can be called pulsing which doesn't do either motor any good.  Once the Whale has pumped water passed the Non Return Valve (NRV) that is connected to its pressure switch, no water should flow back through the NRV into the tank.  If it does, there is a fault with the NRV.  If the water pressure forward of the NRV becomes too high, the pressure switch will switch the pump off.  Unlike Whale impeller pumps, diaphragm pumps have a series of valves that open and shut and can cause an uneven water flow which can also be called pulsing.  When this happens an accumulator can be fitted to even the flow out but the general consensus is that the Shurflo doesn't need it as its natural flow is even enough.

Same here kaspian. Had my Kemerton for over six years and had no issues with my Whale submersible. Works every time!
Hope I'm not tempting providence here!!

Frank

I agree almost completely with your views Caraman apart from if the pressure is high enough to stop the nrv being lifted off its seat before the switch kills power to the pump excess pressure will be bled past the impeller smoothing forward  flow. A diaphragm pump once the inlet valve closes can only pump water forward by the diaphragm  - or stall.  Those  reporting  vibrating pipe issues experienced  who have changed pump type  indicate that in many systems which may be van /model specific depending on pipe run length etc  etc an accumulator type device  might help to smooth out the pulses when demand is low rather than just suffer water /pipe hammer.  

Kaspian, I think I understand you.  Throughout all our caravanning and now motorhoming we deliberately have not run the taps at half cock as it makes the pump repeatedly go on and off which isn't good for any motor.  So this type of pulsing/knocking isn't an issue for us.  The higher level of pump noise in the bathroom when the tap is fully open may be resonance and/or the transmission of vibration from the Shurflo through the plastic pipes but it isn't a big enough issue to make us want to do anything about it.  The only time our Shurflo made an alarming knocking noise was when I hadn't seated the 'o' ring properly on the water stainer and as a result it was sucking air through the system.  The only disadvantage of the Shurflo is that it takes up a bit of space on the floor of the offside bed/seat locker.  The advantages are it has a reputation for longevity, parts of it can be repaired, if it goes wrong it is easy to access, it can be run dry for relatively long periods which can also be of benefit when draining down the system, it doesn't require priming, it doesn't need an NRV and no water will get past it back into the tank and there is no requirement to fiddle around with the pressure switch.  It was predominantly the latter which drove us away from the Whale as we found the pump would keep coming on for 5 seconds as if there was a leak, so much so that we had to turn the pump off at night.  We don't have this problem now.  If the pump does come on its for 1/2 a second and we barely notice it.

Hi Caraman , sounds like you may have had a bit of grit or something allowing weepage past the NRV causing seepage  thus whenever  the pressure drops past the set level the pump activates to pressurise again. This gives the characteristic running for no apparent reason every few minutes/hours unless there was a genuine leak!  I have also  heard that argument before from the die hard Shurflo fans  where taps should only be run fully open to avoid pipework rattles- usually from those who have converted  to shurflo!  In the past I have had vans which used diaphragm pumps ( possibly Reich?) and they worked fine.. I always switch off the pump at bedtime  and on leaving the van unattended as have experienced fellow campers who did not and came home to an inch of water on floor as a pipe fitting popped and pump dutifully emptied the underslung tank into the van at floor level during their absence.
      As I said I don/t care one way or the other  as I have no shares in Whale  but to blindly rip out the pump provided  that has been proven and   used  for tens of years in numerous applications  and for most  without issue seems silly especially as many less technically minded will then have to factor in labour and fitting costs too and possibility of a surge damper/accumulator required adds up to a fair bit of cash.   
          In PVC  's space is at a premium anyway so a submersible makes sense, in coachbuilts take your pick as there is usually somewhere to bung a shurflo or other perfectly good diaphragm pump!  

kaspian wrote:but to blindly rip out the pump provided  that has been proven and   used  for tens of years in numerous applications  and for most  without issue seems silly  

The action I took to replace the Whale and its pressure switch & NRV was neither blind nor silly and had the full support of the AS Service Centre at Willersey who carried out the work.  For 3 weeks of our first month of ownership we couldn't use the van because we were waiting for a new Whale pump to be fitted under warranty by our dealer.  Leaving aside warranty issues, had it been a Shurflo I could have replaced it myself.  From the outset the Whale displayed this irritating characteristic of switching itself on for 5 seconds sometimes as often as every 15 minutes but the dealer couldn't find a leak.  Eventually I found the smallest of drips coming from the Truma drop valve so back to the dealer to get that replaced but the problem remained.  After some research I suggested to the dealer that it might be the Whale NRV by the pressure switch but he denied there was one let alone that it could be dismantled and cleaned.  Eventually I took it back to the dealer for 5 days who came to the conclusion that the Truma NRV he found between the hot water tee-off and the Truma drop valve was in the wrong place so he moved it in series with the Whale pressure switch NRV which he denied existed.  At this point I lost confidence in the dealer (I had other problems as well) and booked it in to the AS Service Centre at Willersey who reinstated the Truma NRV where it should have been, replaced the Whale pressure switch and NRV and replaced the shower mixer cartridge which leaked very slightly if it wasn't completely closed.  But the problem still existed and we were sensitised to it.  During numerous experiments I showed that neither of the two Whale NRVs would stop water flowing back into the fresh water tank when the water pressure was released which Whale said should not happen.  I admit it would have been interesting to look inside both Whale NRVs to see if there was grit in them but that didn't happen.  I thought about doing it myself but it was under warranty and the first Whale pressure switch NRV was barely accessible buried under the EC700 PSU and a mound of wires - the AS Service Centre moved the second one to a more accessible position where the Shurflo is now.  Fitting the Shurflo was the best thing I did.  But there is another twist to this tale.  Last month my Shurflo stopped working and had to be replaced, which is unheard of, but at least it lasted longer than my first Whale.  So you can just be unlucky.  The good news is that everything now seems to be working OK and we like our Nuevo with its Shurfo. 

Hey , If it works for you - excellent !  

Hi , really pleased you have got to that position Caraman, we just had the Whale pack up and the decision was quite easy ,replace cr#p with cr#p or fit something vastly superior! We were out of warrantry  so with a lot of help from this forum I did it myself and have never looked back . We do get the Knocking from behind the shower partition very occasionally ,but just like Gromit Ill live with it ,perhaps one day Ill fit a pressure stabiliser ,but its not really an issue ,so Ill probably leave well alone! The caravans I have observed normally have those roll along water tanks ,so the application is I guess is quite different ,obviously more suited to the Whale submersibles traits! Kind regards            Paul

The reason that I replaced the Whale with a Shurflo was solely because after over 6 years the Whale failed.  On my prevous Hymer the submersible pump was still going strong when we PX'ed after 11 years so I would not say that submersibles are rubbish.  I swapped to a Shurflo because I did not then have to remove it and add a pick-up in the tank - both of which I could have doen through the hatch that my van has.  I was also concerned about Whale longevity as I think that the Hymer probably had a different brand.
I agree totally with what folks say about the pulsing and I would much rather have a slower pulsing at low volumes for all the cogent reasons given - an accumulator would help with that, just as the hot tank itself does on the hot side.  What I am less happy doing is to run cold at full bore and to thereby waste water when washing hands and I don't need a bowl full.  Shurflo specify a half metre of flexible pipe in the installation (which I have included) but, although it helps with general noise level, it does not absorb the pulsing.
If the Shurflo pegs out as quickly as the Whale did then I will replace it with another submersible which does handle over-delivery due to low flow rates naturally, as Kaspian says.
I have asked previously if anyone has used the Whale Tee'd single pipe accumulator which, being smaller, is more easily accommodated than the Fiamma type.  But I don't want to get into the stale water retention argument as well!
I do find winter drain down more difficult with the Shurflo because it does not allow any back-flow AND because I feel the need to empty the strainer - which is essential.

Hi Ron , yes as I mentioned earlier ,our Hymer Swing had an 8yr+ submersible which never missed a beat so its not just because its that type of pump , I just guess that the Hymer type used is superior to the whale ! Regards          Paul

gassygassy wrote:… As well as that it keeps the hot water pipes hot. That is a requirement of modern house building - did you know? All hot water pipes in a new build house have to be insulated. Being sceptical I wondered about the benefits, and as insulation costs virtually nothing I did it to the hot pipes in my house. What a difference! Two hours after you run a hot tap, you turn it on again and hot water comes out, you don't have to wait for all the cold to run away down the drain first. . . .

I did the same thing in our house; I lagged the hot water pipes and I put insulation round the central heating pipes where they ran under the floor. As you say, what a difference! It hadn't occurred to me to lag the pipes in the MH - an obvious thing to do, I don't know why I haven't thought of it before.

I am just wondering about the common references here to the knocking of the water pipes behind the swing wall shower. In one camper I had, a Rapido, the kitchen sink drain was run in unnecessarily small diameter pipe through seven 90 degree bends before it went down to the waste tank. I worked out that I could fit domestic 32mm drain pipe through its route, and reduce the number of bends to 3. However the 'straight run' route I wanted ran under a false floor under the beds so the 32mm pipe wouldn't just push through the void, because there was a wiring loom in the way. I did manage to feed a 15mm pipe through though. So with the 15mm pipe in place I fed the 32mm pipe over the 15mm pipe which acted as a route guide past the wiring loom and other obstacles under the false floor and popped out over the waste tank. I then removed the 15mm pipe from inside the 32mm pipe, connected it to the sink and the drain then went super-fast with a satisfying sluuurp guurrrrgle. Now I ask myself why couldn't Rapido have done that in the factory?
Anyway I am thinking of applying the same principle to the Nuevo water supply pipes to the washroom. If I disconnect the pipes under the o/s bed, and maybe under the wardrobe if necessary, I should be able to push 15mm insulation along the pipes into the washroom. Hopefully. The standard diameter of motorhome water pipes is 12mm so in theory the 15mm sleeving would just slide over the pipe.
Maybe another MMM article? IF it works. . . .
Naturally I am also thinking of increasing the drain diameter of the Nuevo kitchen sink which makes a glacier seem fast in comparison. It runs along behind the cooker, and presumably then drops vertically to the waste tank. If they ran it in a straight 45 degree incline from the sink to the floor above the waste tank it would flow much much faster, and the angle of dangle of the motorhome on site wouldn't matter so much as it does now . . . . .another MMM article? IF it works . . . . .

can the replacement Shurflo pump be fitted to water pipes going to the pressure switch after you remove it?

Wondera - Willersey did it for me but in principle yes.  Full instructions by those who have done it themselves are here -https://www.autosleeper-ownersforum.com/t23133-replacing-a-submersible-pump-with-a-shurflo I am sure you will get plenty of advice from forum members who have done it themselves.

wondera wrote:can the replacement Shurflo pump be fitted to water pipes going to the pressure switch after you remove it?

I see no reason why not. However, you need to consider where to mount it where it will not reverberate. My pressure switch was next to the metal box that houses the gas bottles.

Gassy - my water feed pipe has a y junction under the wardrobe where the supply goes off to feed the hot tank. And I guess there are similar junctions under the shower floor to split sink, shower and kitchen.

paul bullock wrote:Hi Ron , yes as I mentioned earlier ,our Hymer Swing had an 8yr+ submersible which never missed a beat so its not just because its that type of pump , I just guess that the Hymer type used is superior to the whale ! Regards          Paul

Mine was a Camp Swing - £28k in 2001. Swapped in 2012 because upholstery was getting tatty (our bad choice of a moquette) and 5th gear was just starting to jump out. It was a QUALITY vehicle but by 2012 the Hymer build had got a bit plasticky

inspiredron wrote:

wondera wrote:can the replacement Shurflo pump be fitted to water pipes going to the pressure switch after you remove it?

 you need to consider where to mount it where it will not reverberate. My pressure switch was next to the metal box that houses the gas bottles.

I am not familiar with the exact layout of a 2009 or 2012 Nuevo.  For my 2019 Nuevo, the Whale pressure switch/NRV was on the floor tucked under the EC700 Sargent power control system PSU behind a plastic ventilation grill at the rear of the O/S seat/bed locker.  When Willersey replaced the Whale pressure switch/NRV with a new one, they moved it in front of the ventilation grill so it could be better accessed for adjustment.  When they later fitted the Shurflo it went pretty much where the Whale pressure switch/NRV had been second time around.  The water pipe from the fresh water tank that had previously gone to the Whale pressure switch/NRV went to the inlet of the Shurflo via an in-line water stainer attached to the pump.  When the water comes out of the Shurfo it splits to the cold water taps and the Truma Combi just as it did before with the Whale pressure switch/NRV.  The Truma Combi feed goes past the Truma drop valve through a Truma NRV to the Truma Combi and from there to the hot water taps.

Sorry - I got that wrong.  The last sentence should read The Truma Combi feed goes through a Truma NRV past the Truma drop valve to the Truma Combi and from there to the hot water taps.

thanks to everyone for there help and the info was spot on  thanks again

Let me throw an observation into the mix on the pipe vibration noise. I have observed over 1000 Ltrs of water, hot and cold pumped through the Surflo in our Nuevo under very variable climatic conditions.
Definitely when the pipes / climate is warm there is virtually no noise. When the climate is cold and hot water is pumped the noise starts.

Last time out I noticed less noise in the bathroom generally. On one occasion when it was noisy I moved the swing wall and it quietened. I guess that the pipes are touching the swing wall which is acting as a sound amplifier. When I have a moment I will remove the inspection cover and add a bit of pipe insulation to pad the pipes, particularly the cold.

That's very observant marconi and Ron. I hadn't noticed the inspection cover. I won't insult you by asking where it is, but I'll go and look. Only thing stopping me (for no reasonable reason) working on the camper is that it is shrouded in a proper caravan cover so it takes 5 minutes to get inside! I can though so I should, specially if the temperature is over 10 degrees outside, like today.

I think that warmer pipes are more flexible and expand so you can get more noise from them when the tap is turned on-what do others think?

On the other hand, when warm the pipes would be more floppy and therefore absorb the pulses better without rattling against the panel. . . . . who knows, till we have fixed it?
Anyway, on new house builds it is compulsory to insulate all hot water pipes to save energy. When I learned of this I thought 'that's just another unnecessary thing thought up by a committee of building standards bods' but as insulation costs nuthingpencehalfpenny I set about doing it on my 1972 bungalow. What a difference! Water stays hot in the pipes for two hours!