Kevin1946 Posted November 2, 2017 Share Posted November 2, 2017 Hi, water reads empty when it has 20 LTR of water,then it starts to go up as I add water,i have opened the tank to do as is suggested and clean the sensor rod BUT all I found was a tube that I think is the gauge but it only goes half way down the tank(it is like a tube) .the tank is a square tank inside the wardrobe it is a Elddis 400rl 2004 I think it has some work done to the tank as there is no drain tap (it is blocked off) Should there be something in the tube that halls to the bottom of the tank to rise as I fill it up. I am only using it as a day van and don't need to carry a load of water and would like to carry 15/20 LTR of water. I HAVE LOOKED AT The site before I asked as I am sure you are all fed up with new Motorhome's like me (I have a lot more questions ) I LOVE THE VAN sorry I didn't buy one years ago.When the sun shines we take it out,I have put 4000 miles up from July and never left Ireland yet.If the sun shines in the morning we are gone, we have only had one night away,all the rest are day trips,the longest was a 400 mile trip in a day (200 there 200 back ) Kevin Link to comment Share on other sites More sharing options...
Grumblewagon Posted November 3, 2017 Share Posted November 3, 2017 Some level sensors did have a tube surrounded by a number of probes. These would not register until the tank was approx 1/4 full. More often, there were two probes and a level meter (by Zig) these were notoriously inaccurate. What wires are attached to the sensor? What sort of level indicator do you have - a meter or LEDs? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 3, 2017 Share Posted November 3, 2017 The sensor system used to measure the contents-level of a motorhome’s fresh-water tank commonly can involve multiple electrical contacts screwed through the tank’s side or ‘probes’ that extend downwards inside the tank (see attached photo). I think Elddis may have fiited a pretty small tank to your motorhome (45 litres?), so if you only have a long and a very short probe, and the long probe only extends about half way down inside the tank, you’ll have a crude system that will read ‘empty’ when the tank is actually half full (eg. about 20 litres for a 45 litres tank). Probe length needs to be matched to the depth of the water tank and, if repairs to the tank have been made in the past, a wrong-length sensor may have been fitted. Having said that, there are many on-line criticisms of the water gauges fitted to older Elddis motorhomes, so if yours can provide a reasonably accurate contents-level read-out above the 20-litres ‘water line', you may be doing well! Link to comment Share on other sites More sharing options...
Brock Posted November 3, 2017 Share Posted November 3, 2017 Kevin, don't worry about posting! We all have to learn. There used to be a Elddis Owners Club but I don't know anything about it now as I'm not an Elddis owner anymore. I'd always recommend joining an Owners Club for the first year at least. My Hymer doesn't register any water in it until it reaches just over 30l [quarter full]. Then it registers at half, three quarters and full. My tank size is 130l and we rarely fill with more than 30l in it so the gauge is not much use to us. We use our van for day trips as well as overnighters. We have the Lake District, Yorkshire Dales, Peak District and Snowdonia within a two hour drive. Link to comment Share on other sites More sharing options...
Alanb Posted November 3, 2017 Share Posted November 3, 2017 Kevin, May I start by recommending that you investigate refitting the drain cock, as it will facilitate emptying the tank between trips. From what you have described, I think that what you have is a capacitive probe with analogue read out. As the system appears to function when the water level is high enough, could it be the case that the electrodes are concentric? However I am not aware of such an arrangement, and perhaps someone else could help here? Whatever the system, as Derek has stated the electrodes are too short for your tank. If it is not possible to identify the make of the system and obtain a suitable replacement electrode of the correct length, there are at least two possibilities. 1. Live with it and fill the tank until you get a reading, as this would suit your useage pattern. 2. Retrofit an alternative system such as the CBE system in the photograph posted above by Derek. Alan Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 3, 2017 Share Posted November 3, 2017 I think the potential problem Kevin has is that, as he plans to carry no more than 20 litres of water, he needs (or would like) the ability to obtain contents readings from 20 litres downwards - which the present system cannot do. Few motorhome water gauges are accurate In the low-to-empty range, but this does not usually matter as people will be looking to refill the tank well up then, not just back to the 20 litres level. Link to comment Share on other sites More sharing options...
Kevin1946 Posted November 3, 2017 Author Share Posted November 3, 2017 Thanks for all the replies 1)The tank size is about 60 LTR 2)The gauge is the battery gauge it reads water when you press the water switch 3) I empty the tank by opening the water heater tank which seems to work. I THOUGHT of lowering the tube down in the tank so it starts to read at empty.? OR CAN I GET A Retro fit unit? Link to comment Share on other sites More sharing options...
Brian Kirby Posted November 3, 2017 Share Posted November 3, 2017 As others have said, Kevin, the gauges don't work like fuel gauges. They go up/down in steps. Ours has a 100L tank, and the gauge indicates four stages. 25%, 50%, 75%, and 100%. Basically, when it reads 100% it is between 100% and overflowing, when it reads 75% it is between 75% and 100% full, when it reads 50% it is between 50% and 75% full, when it reads 25% it is between 25% and 50% full, and when it flashes red it is between empty and 25% full. In your case, it sounds a bit as though the gauge may respond to air pressure in the tube, so when the water level is below the bottom of the tube it reads nothing and, once the water level gets to the tube (and you have about 20 Litres in the tank) it begins recording. Then, as the water level rises the air trapped in the tube becomes progressively pressurised, and the gauge scale represents pressure as water level. So, if all you want is about 20L, the simplest solution seems to be to fill the tank until the gauge begins to move, and then stop filling. If that proves insufficient in practise, ago on a bit with the fill, and then note the gauge reading that equates to sufficient water for the next time you fill. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 3, 2017 Share Posted November 3, 2017 Kevin My 1996-built Herald motorhome had the type of dual-purpose battery/water gauge you’ve described. It was made by ZIG (as mentioned above by Grumblewagon) and was useful but far from accurate. (ZIG parts will normally carry the “ZIG” name, so you may be able to confirm whether the gauge fitted to your Elddis is ZIG-made.) Some ZIG parts are still avaialbe, but I’m doubtful that the dual-purpose gauge is. Besides which, it seems to be the tank-sensor’s lack of length that’s the stumbling-block not the gauge itself. As long as your gauge will provide some sort of useful readings between 20-litres to 60-litres, I’d favour Alanb’s Option One and llearbn to live with thesystem as it stands. From what you say, when the gauge shows ‘empty’ there is still 20 litres in the tank, which is all you find it necessary to carry. At the ‘empty’ point you know you’ve got 20-litres and you should have a pretty good idea of your rate of water-usage. I’d just carry a 10-litres container of fresh-water and, if it looked like the 20-litres in the tank might run out, I’d top up the tank from the 10-litres container. Link to comment Share on other sites More sharing options...
Kevin1946 Posted November 3, 2017 Author Share Posted November 3, 2017 Thanks It looks like my one works as it is made to do,I will try to lower it down in the tank and I will report back and let you know if it is any better.The tank is easy to get at as it is in the wardrobe under a shelf. Kevin Link to comment Share on other sites More sharing options...
tonyg3nwl Posted November 3, 2017 Share Posted November 3, 2017 If you can access through top of tank, then simple solution is to get a dipstick, simple technology!!! Tonyg3nwl Link to comment Share on other sites More sharing options...
Alanb Posted November 3, 2017 Share Posted November 3, 2017 Brian Kirby - 2017-11-03 5:44 PM In your case, it sounds a bit as though the gauge may respond to air pressure in the tube, so when the water level is below the bottom of the tube it reads nothing and, once the water level gets to the tube (and you have about 20 Litres in the tank) it begins recording. Then, as the water level rises the air trapped in the tube becomes progressively pressurised, and the gauge scale represents pressure as water level. Ideally the system described above would need to sense the pressure at the bottom of the tank due to the height of the water above it. Unfortunately the height of the column in the pipe will contribute its own pressure which could become significant. For the system to be balanced, the pressure of the air trapped in the pipe + the pressure due to the water in the pipe must equal the pressure at the end of the pipe due to the height of the water in the tank. Otherwise water will flow in or out of the pipe until balance is reached. The system suggested above is similar to that used to control the filling of washing machines, but in washing machines there is an air reservoir at the point where the sensing pipe enters the drum housing. When water enters the air reservoir a volume of air much greater than the volune of the small bore pipe to the sensor switch is displaced. The pressure in the pipe is therefore increased considerably for a small change of water level in the reservoir, and is close to the pressure at the sensing point due to the water level in the drum. If my logic is wrong, and Brian is correct, it should be a relatively simple matter to extend the pipe with a suitable piece of food grade plastic tubing. Alan Link to comment Share on other sites More sharing options...
Kevin1946 Posted November 3, 2017 Author Share Posted November 3, 2017 Tony, It is easy to get at (15 mins) but the wardrobe has to be taken apart so a dip stick won't do but you have given me an idea to make one that would go in from the filler cap,a curtain wire is flexable and might do,they work on gearboxes that don't have a dip stick. Alan On reading your reply,I will try to extend the tube instead of moving it down,it may start to read sooner. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 4, 2017 Share Posted November 4, 2017 I‘ve never heard of a motorhome gauge that measures water-level via air pressure in a simple tube that protrudes into the water tank, and I can easily envisage how potentially inaccurate and unreliable that would be. However, I’m not omniscient and it would be helpful if Kevin could provide a photo of the sensor. (As he plans to move/modify it, I assume it’s easy to remove from the tank.) This link is to a 2003 Elddis motorhome handbook http://www.elddis.co.uk/documents/Handbooks/2003/motorhome-handbook.pdf The control-panel fitted to the “Autoquest” range is described on Page 22 and matches Kevin’s information that the analogue ’needle’ gauge can show the contents-level in the fresh water tank as well as the voltage of the motorhome’s starter and leisure batteris. I think the control-panel is not a ZIG product (as these are normally clearly marked with the Zig logo) and there is nothing obvious in the photo to establish its manufacturer. It might have been a Plug In Systems or a BCA panel (or something else) but I can’t find a better image on-line or any comments to identify the maker. As the gauge itself works and it’s the in-tank sensor that’s not providing measurements below 20-litres, it may not matter who the panel’s maker is. Link to comment Share on other sites More sharing options...
Brian Kirby Posted November 4, 2017 Share Posted November 4, 2017 Derek Uzzell - 2017-11-04 8:05 AM I‘ve never heard of a motorhome gauge that measures water-level via air pressure in a simple tube that protrudes into the water tank, and I can easily envisage how potentially inaccurate and unreliable that would be. However, I’m not omniscient and it would be helpful if Kevin could provide a photo of the sensor. (As he plans to move/modify it, I assume it’s easy to remove from the tank.)................... Nor have I Derek, but as the probe was described as a tube, I was left wondering why the maker would select a tube in preference to a simple rod. On the basis that there would be some logical reason for that (to me odd) choice, sensing air pressure to provide a reading was the assumption I came up with! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 4, 2017 Share Posted November 4, 2017 Well, we live and learn... The following link shows the ‘tube’ water tank level sensor used by Bailey https://www.bailey-parts.co.uk/product/1030273 and this Bailey Approach-related blog https://baileyapproach.wordpress.com/2015/05/08/mending-the-water-level-faults/#comments says that “...this tube is full of air to create the pressure differential from the water.” It also mentions extending the tube. I don’t know if this type of sensor is what Kevin has on his 2004 Elddis motorhome, but it’s evident that tube sensors do exist. Link to comment Share on other sites More sharing options...
Brian Kirby Posted November 4, 2017 Share Posted November 4, 2017 Well, if he has, and he follows the advice on modification, I'd suggest that (unlike the author of the cure :-)), he first gets all of the ink out of the biro tube! :-D Link to comment Share on other sites More sharing options...
aandncaravan Posted November 4, 2017 Share Posted November 4, 2017 I rebuilt our Washing machine many moons ago that used air in a pressure tube to work out the height of the water in the drum. Prone to blocking with soap powder and overfilling, but we then switched to liquid soap and never had another issue. Link to comment Share on other sites More sharing options...
Kevin1946 Posted November 4, 2017 Author Share Posted November 4, 2017 Derek the tube type you show for the Baikey is the same as the one in my Elddis,when it is in the tank the tube only goes 1/2 way down the tank so 20 LTR comes up to the start of the tube and it starts to read then. It works perfectly as soon as water reaches it. Is there any way I can extend it to reach the end of the tank Kevin Link to comment Share on other sites More sharing options...
Alanb Posted November 4, 2017 Share Posted November 4, 2017 Sorry Brian, As Derek has stated we live and learn. However it is stated that the tube has to be full of air. Kevin, Have you scrolled down the Bailey parts page linked to by Derek? There is a 380mm sensor listed further down the page? However I would think about it carefully before parting with your cash. Alan Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 5, 2017 Share Posted November 5, 2017 Kevin/1946 - 2017-11-04 5:49 PM ...Is there any way I can extend it to reach the end of the tank Kevin The following link (provided in my last posting) suggests a way to extend the sensor-tube https://baileyapproach.wordpress.com/2015/05/08/mending-the-water-level-faults/#comments The writer has extended the sensor-tube using a biro-pen’s plastic casing (photo attached) but I’m sure a less crude approach would be possible. Apparently it is important to keep the internal diameter of the add-on extension small, but if you use something with a similar internal diameter to that of the original sensor, I suspect that should be OK. Link to comment Share on other sites More sharing options...
Brian Kirby Posted November 5, 2017 Share Posted November 5, 2017 Alanb - 2017-11-04 9:34 PM Sorry Brian, As Derek has stated we live and learn. However it is stated that the tube has to be full of air......................Alan If it is a vertical tube, open at the lower end, and closed at the top, it will be full of air before water is added to the tank. As water is added beyond the level of the bottom of the tube, the column of water in the tube will begin compressing the air in the tube. The higher the water rises in the tank, the greater the compression of the air in the tube. That rising air pressure is what is being recorded, with the readout from the pressure sensor transmitted to a dial/digital gauge where it is presented as a representation of water level. Link to comment Share on other sites More sharing options...
Alanb Posted November 5, 2017 Share Posted November 5, 2017 Brian, The "Sorry Brian" which you quote above was intended as an apology, as you had correctly speculated a pressure operated level measuring device, and I had cast some doubt on this possibility. I have no argument with what you state above. You are absolutely correct in what you state. I was making the point that if the tube is partially full of water, the pressure of the air will be less than that at the bottom of the tank, which is what the gauge is trying to measure. Alan Link to comment Share on other sites More sharing options...
Kevin1946 Posted November 6, 2017 Author Share Posted November 6, 2017 Yes I have looked at the post and I will do it this week.First I will try a new 12 mm tube the full lenght,if it does not work I will put the old 12 mm tube back and extend it with a 10 mm inside the 12 mm tube. I will report back as soon as it is done. THANKS for all your time Kevin Link to comment Share on other sites More sharing options...
Brian Kirby Posted November 6, 2017 Share Posted November 6, 2017 Alanb - 2017-11-05 8:12 PM Brian, The "Sorry Brian" which you quote above was intended as an apology, as you had correctly speculated a pressure operated level measuring device, and I had cast some doubt on this possibility. I have no argument with what you state above. You are absolutely correct in what you state. I was making the point that if the tube is partially full of water, the pressure of the air will be less than that at the bottom of the tank, which is what the gauge is trying to measure. Alan Apologies Alan, I had simply misunderstood your reference to the tube needing to be full of air. Odd system! :-D Link to comment Share on other sites More sharing options...
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