Nuevo Water Level Sensor - Repair/adjust

Hi all,

Couldn't find anything on this with a search, but my water level sensor on the Nuevo is a bit vague to say the least.

It reads full ok, but continues to do so probably to around a third of a tank where it suddenly drops to the top of the red level where it then sits until completely empty.

It's not a big deal, but when on sites without showers it's nice to know there's definitely enough water to squeeze a shower in and not be left with soap my eyes trying to find a bottle of water to throw over myself.

I'm assuming the float is either sticking or the sensors the float runs over aren't reading anymore so only a high and low level is monitored.

If it's a nightmare job to get to I will just live with it, but if anyones repaired/replaced one I'd be interested to know what's involved and how much effort it is.

Thanks all,
Rob.

There are various threads about this on the Forum, which a search will reveal.

In short, the water level indicators (fresh and waste) are not reliable or accurate. They give an approximation, at best. They are prone to failure, in some cases because of limescale on the sensors. Members have effected remedies (as they have helpfully described in the past), but not without effort.

I think that the current indicators are not as good as the old Zig one which I had on a Clubman years ago. The Thetford WC on my Nuevo doesn't even have an indicator to show the level of flush water remaining in the cistern.  So I have to guesstimate how much is left - and remember to top up every few days (Its capacity is 7 litres only).  And in the same way I suggest you simply remember to top up your fresh water (and discharge the grey) every few days.  Don't get hung up about the indicator!

Thanks.

The search function is a little flaky unfortunately if you don't get the wording exact.

I tried:
Water level indicator
Water level
Water gauge
Water level
Water tank repair

Just tried "water indicator" and finally got a thread.

I'll carry on with that thread. I don't get hung up on it, as I mention above it's not a big deal, but is a "nice to have" and I'm happy to bodge around with the sensor as I can't break something that doesn't work properly anyway, so just wanted to see if anyone had had any success in a repair etc.

Cheers.

I am not familiar with the water level indicator on your Nuevo but suspect it is the same as many of the recent vans, inside the tank are four sensors one above the other corresponding to the levels 25/50/75/full and these as Cymro says get covered in limescale and cease to work in a short space of time.

Marquis fitted a hatch in our tank ( Henderson hatches website) which allows access to the tank without dropping it and gives the ability to clean the sensors within a few minutes and also to keep the tank clean. Worth thinking about and not frighteningly expensive.

groundhog wrote:Marquis fitted a hatch in our tank ( Henderson hatches website) which allows access to the tank without dropping it and gives the ability to clean the sensors within a few minutes and also to keep the tank clean. Worth thinking about and not frighteningly expensive.

Thanks for that.

Yeah the other thread mentions the studs, and I can see now how a layer of scale would prevent them reading.

I've ordered a bag of citric acid to give it a good de-scale and see if that works initially and then the next option would be the manual cleaning.

I like the sound of the hatch, but think that would be a last resort as it's only a "nice to have" I guess and the other half has a shed load of chores lined up for me before I could start something like that.

Cheers,
Rob.

My Nuevo has probably got the same gauge (shared gauge with battery condition?) My gauge  shows just short of full when filled, then drops back to just over half and then will drop to just a quarter but when first pressed, it will always read full and I have to hold the rocker in for around 30 seconds before it drops to the lower levels. At one time it would only show full all the time but seems to have returned to 3 stages again lately.

Paulmold wrote:My Nuevo has probably got the same gauge (shared gauge with battery condition?) My gauge  shows just short of full when filled, then drops back to just over half and then will drop to just a quarter but when first pressed, it will always read full and I have to hold the rocker in for around 30 seconds before it drops to the lower levels. At one time it would only show full all the time but seems to have returned to 3 stages again lately.

Ah, that is interesting - yes its the same gauge and also shows full pretty much all the time until the level drops to a quarter (when it's nearly empty) and then never reads empty even when the pump's gurgling with air, so deciding on whether to have a shower a day or too into a trip is like a soapy Russian Roulette.

Will try the hold for 30 seconds trick to see if that works the same on mine, as seeing it has dropped to the half/quarter point will at least give an idea we need to think about a fill.

Just thought: I don't suppose it's a Zig unit is it?  Paul's reference to reading both water and battery makes it sound like the Zig which wa fitted to 1998 Clubman - which had a projecting screw adjuster whereby to calibrate the guage. It worked well. Fill to brim; calibrate correspondingly. Acceptably accurate.

Not a zig.Its a MES panel.

No the gauge is not very helpful in fact as good a guide as any is that its full when you fill it and its empty just after the warning buzzer sounds. Chocolate teapot anyone???

No buzzer with the MES system either. It's a very basic system but that has its advantages too.

Paulmold wrote:It's a very basic system but that has its advantages too.

The simpler the better in most cases.

I would be happy with a viewing window in the side of the van so I can see the actual water level.

I have given up with mine on the grey waste, it was fixed every time I went to AS but failed again a few weeks later. So plug disconnected and bagged 
Funnily enough the fresh water has worked faultlessly since new. (That's seriously tempting providence )

Noggin wrote:

Paulmold wrote:It's a very basic system but that has its advantages too.

The simpler the better in most cases.

I would be happy with a viewing window in the side of the van so I can see the actual water level.

That's actually a spiffing wheeze, why not have one similar to the level indicator for the Thetford flush tank, a simple clear plastic tube, manometer stylie?

[quote="meanchris"]

Noggin wrote:
That's actually a spiffing wheeze, why not have one similar to the level indicator for the Thetford flush tank, a simple clear plastic tube, manometer stylie?

I did think that, but you'd need the top of the tube to be open to the atmosphere (albeit only a tiny hole), and I guess then there might be problems with the possibility of sunlight promoting microbial growth which then goes into the water tank as the level drops. With regular cleaning would be ok I guess, but might be a modern H&S issue stopping manufacturers doing it.

Either way, something as simple as that would be perfect and none of the issues we all have with these electrickery gizmos.

Our Broads syndicate boat had a float type indicator in the two large toilet tanks which were always getting clogged up, for obvious reasons and we looked at replacing them with some alternative.
In fact one of the syndicate owners had connections to a company that manufactures a quite nice level indicator.

We didn't eventually use their indicator in the loo tanks but it might be worth me having a look at our records to see whether it would be a good option for our water tank.
We don't drink the water from the tank anyway, (I don't even like to clean my teeth with water from the taps) but I would have thought that the risk of contamination is no worse than using a stored piece of hosepipe, or our 10l water carrier, or of the water standing in the bottom of the tank for weeks between fills.
We could always put a couple of purifying tablets into each full tank (I'm not sure about Milton, after what it did to my beloved Stanley flask It might damage any metallised surfaces in the taps and fittings), and the water gets used so quickly when travelling that there's no time for large concentrations of microbes IMHO.

All interesting stuff.

Thats a good point about using hoses etc always worth running the hose for a while, but I guess it will still have a small amount of stuff in there that will find it's way in the tank - I must admit I'm the same, the water is only used for washing up and showers.

Always take bottled water for teeth cleaning and drinking.

I remember when I first looked over our Transit PVC back in '06 I asked about the lack of a water level indicator and the response was that they'd not found one that was accurate or durable, so didn't bother fitting one..

On our next van, an Adria there was an indicator, in combo with others and it gave a fairly reliable indication. However to see the water level you just had to lift the dinette seat cushion, lift off the seat bottom panel and there was the tank, filling the whole underseat space. The tank was obscure plastic but you could see the water level and if you wanted you could unscrew a very large blue plastic access top and see the water, or use a dipstick.

Weighing the water, via a pressure sensor or strain gauge would probably be the best way, the electronics out of a cheap digital weighing scales would do the job.

You could put a plate under the underslung tank and mount the sensor on that, then sit the tank back on top.

You can deduce a very accurate volume measurement from the known weight of a kilo of water, in fact you don't even need a conversion - 20kG is 20 litres, especially if the scale is zeroed with an empty tank.

The only reliable water gauge I have seen is the one on my brothers boat which is a simple pressure gauge in the piping under the tank.
The gauge on our van refused to work at the start of our recent trip but eventually started to give reasonable readings.  Only enough it was the use of softer water (less conducting?) that started it to work.  This seems to be the wrong way round.   Perhaps the water cleaned some scale off the studs.

In my opinion, measuring the conductivity of variable water is a silly idea in the first place.

The machines I work with require low conductivity to avoid electrolytic action and most have resin de-ioniser cartridges to reduce the conductivity to below 50umho, (I've seen some as low as 2-3umho)

I've seen ordinary mains drinking water as low as 100umho from a small Peak District reservoir and as high as 1mmho. (the figures I've seen for typical drinking water don't tally with what's posited on Wikipedia for some reason, don't know why that is, unless all the water I've seen measured has been very "soft")

Anyway, I personally doubt that the simple electrode meter in my van can determine the level by measuring the water conductivity, unless it's kept immaculately clean, calibrated and always from the same source.

They do not quite work like that because of the variable conductivity of the  water.  They have a series of stainless steel studs up  the wall of the tank. (or sometimes rods of variable length). They either make contact or not hence the coarseness of the readings.  If they use a high resistance detector this should work OK with different waters until the studs get covered with film of calcite.
I still think that a pressure system would be better.

safariboy wrote:They do not quite work like that because of the variable conductivity of the  water.  They have a series of stainless steel studs up  the wall of the tank. (or sometimes rods of variable length). They either make contact or not hence the coarseness of the readings.  If they use a high resistance detector this should work OK with different waters until the studs get covered with film of calcite.
I still think that a pressure system would be better.

OK, interesting, thanks for that. The ones in our boat were simply two stainless rods which I (probably wrongly) assumed were trying to measure the water resistance directly, in the same way that the Elga system consisting of a block with two electrodes that the water passes over.

I also like the idea of a pressure sensor below the tank, like a barometer, or a cannibalised Aldi weighing scale with the readout and zero button mounted in the hab area somewhere.

My water level indicator stopped working at the start of recent 2 month trip to France.
Back home I have managed to reach and clean the level studs through the bottom tank access. Not easy with the arm in up to the arm pit!!
Disappointing to find the studs are only threaded set bolts and as such will only help to attract scale formation. Cheap option by AS, should be purpose made SS pillars. I would change mine but can not remove the top studs with the tank in place.

Well interestingly I gave mine a descale yesterday and it has all started working, so definitely an issue with scaling of the studs as mentioned.

I bought a 500g bag of citric acid and dissolved into a watering can and then poured in to the tank and topped up to brimming.

Left it 24 hours and have drained the system and a few flushes to get all the acid out. I'm not sure if it's just me imagining it, but I'm sure the pump is also working better now and kicking out a higher flow rate.

Might do this as part of my annual clean down ready for winter now just to keep on top of it.