StuartO Posted October 13, 2017 Share Posted October 13, 2017 My B Class, 2006, Hymer has a submersible water pump, dual impeller, which lacks umph, especially for showering. I have replaced it with a new same type and it does perform as well as it's ever done. Can anyone suggest a better type of pump, to deliver a higher flow rate? Link to comment Share on other sites More sharing options...
aandncaravan Posted October 13, 2017 Share Posted October 13, 2017 Stuart, I like the Comet VIP which has a better, on paper, flow rate than the Reich twin submersible. But Derek thinks it won't perform as well in a real situation, and I suspect he might be right. When we have fitted uprated pumps the 'improvement' has always been slight, which I never really understood and didn't follow any further, until : My Shower had poor pressure and I uprated the pump to a Comet VIP and it made little difference at the shower but the Kitchen sink taps flowed a bit better when on both Hot and Cold. I then fitted an additional Inline pump and that made no discernible difference anywhere. I therefore concluded that the 'pressure' was not the real issue, but restrictions in the pipe work to the shower. There were several push fit joints in the pipework between the Water feed and the shower which I removed, all except one. With the pipe not connected to the Bathroom Sink, Water shot out of the changed pipework with really good flow. So I then connected the revised pipework to the Bathroom sink assembly with great expectations. The water flow out of the bathroom sink tap, which the shower fed from, improved slightly but the shower flow was still not great. I removed the shower pipe/head to find the water flow from the Sink section was not as good as expected. Looking at where the Shower Hose/head attached at the sink tap revealed quite a restrictive opening and I kicked myself for not starting there first!! When I removed the whole assembly I could also see that the pipe work 'tails' on the taps had small apertures that would require a huge increase in pressure just to make a small difference in flow rate. So the next stage was to find a better Sink Tap/Shower unit which is still on the 'to do' list. Suggest you start by removing the primary cold feed pipe to the bathroom shower assembly to check the flow there, I suspect it will be quite strong, just gets lost through the taps? Link to comment Share on other sites More sharing options...
keninpalamos Posted October 13, 2017 Share Posted October 13, 2017 I've had a similar problem with a Hymer E700 for months. The flow rate was very poor I descaled The pipework, taps, including the shower, tank and water heater (Truma C6000) Fitted a new Comet pump (1bar) for a short time then a new Reich twin ( 1.4bar) all done with minimal improvement. Then, just in desperation I thought it might be a good idea to check the voltage at the pump, which was 11.1 volts :-S I traced the faults back to the Eletrobloc fuse marked "pumpe" which was replaced plus the fuse holder terminals cleaned with a contact cleaner. Also cleaned up all the multi plugs and sockets with a tiny brush, cleaner and a quick blast with an air line to clear any hidden crap etc. Then re checked the voltage at the pump again comparing it with the auxiliary battery voltage, a voltage drop of 0.05. And the shower has never worked as well as it does now and if the solar panels are getting plenty of directional sun and nothing else is being used then the skies the limit. The down side is the hot water doesn't last long as it pumps it out so quickly. It's never going to be as good as a domestic shower but not bad for what it is. Link to comment Share on other sites More sharing options...
StuartO Posted October 13, 2017 Author Share Posted October 13, 2017 Both very helpful replies, thank you. I have noticed that voltage drop at the pump is a factor, so it obviously something that needs looking into. Our shower head was past its sell by date so I bought a seemingly suitable supermarket replacement; just the right flow pattern but limp delivery, hence the interest in more umph from the pump! Settle for what we've got until we get home then thoroughly investigate. A Trumaman at a Showtold me that to get the max shower heat ( for more than one shower) w.ith no heating on, turn the HW up from 40 to 60 deg about 5 minutes before showering, to get the Truma fired up before you start showering. The Truma is designed primarily as a blown air heater, so selecting HW only gets you an inferior response. This technique does seem to make quite a difference. Link to comment Share on other sites More sharing options...
Keithl Posted October 13, 2017 Share Posted October 13, 2017 Stuart, We had a similar problem at home of poor flow from a gravity fed shower after fitting a new mixer, hose and shower head. As the 'old' mixer, etc. had worked fine I suspected the new hose as the primary culprit and found it to be a very small bore, possibly less than 5 mm diameter internally. I found Screwfix listed shower hoses by internal diameter so bought a replacement with 11 mm internal diameter and was amazed at the difference! https://www.screwfix.com/c/bathrooms-kitchens/hoses/cat820280?cm_sp=managedredirect-_-bathrooms-_-showerhoses Could you try replacing the hose with one of a larger diameter? Keith. Link to comment Share on other sites More sharing options...
aandncaravan Posted October 14, 2017 Share Posted October 14, 2017 Stuart, I just had an email with the title, "Help with shower power" and opened it expecting it to be from you!! But it was from a Jean Baird who's engineer has diagnosed a fault with the water pump 12v supply. From the photos I can see the 5a fuse has at some time been replaced with a 10a possibly burning out the Copper track inside the Schaudt box. Suggesting issues with the pump drawing excessive power in the past OR someone has uprated the pump without consideration for the extra power it might draw? So just thought I would add a warning here (for anyone who might go that route, not necessarily you) that obviously any uprated pump should operate within the limits of the 12v circuit supplying the power. Link to comment Share on other sites More sharing options...
StuartO Posted October 14, 2017 Author Share Posted October 14, 2017 These replies have have all been really helpful and sensible - just what a forum is capable of delivering. Thank you guys, well done. The shower hose is clearly of narrow diameter, so it looks like replacing that would be a good start. Then I'll check the cabling on the pump supply, to make sure it's delivering enough volts at the pump. There are microswitches on the taps, so I'll whether they limit the supply to the pump because are only lightweight devices with thin cable. There will be a solution somehow! Link to comment Share on other sites More sharing options...
Alanb Posted October 14, 2017 Share Posted October 14, 2017 StuartO - 2017-10-14 8:27 PM There are microswitches on the taps, so I'll whether they limit the supply to the pump because are only lightweight devices with thin cable. There will be a solution somehow! Stuart, I would expect the micro switches to operate the pump via a relay. Alan Link to comment Share on other sites More sharing options...
starvin marvin Posted October 14, 2017 Share Posted October 14, 2017 If you are a member of HCI, (Hymer owners club) they have a forum. Also on facebook there is a Hymer Owners Group, for which you will have to register. There is loads of info for all kind of Hymer issues. Good luck. Link to comment Share on other sites More sharing options...
StuartO Posted October 15, 2017 Author Share Posted October 15, 2017 Alanb - 2017-10-15 12:34 PMStuartO - 2017-10-14 8:27 PMThere are microswitches on the taps, so I'll whether they limit the supply to the pump because are only lightweight devices with thin cable. There will be a solution somehow! Stuart,I would expect the micro switches to operate the pump via a relay.Alan Indeed. But where is the relay or its equivalent - inside the EBL? Unfortunately Hymer do not provide a 12v wiring diagram as part of the User Guide but Schaudt do, and I have a copy somewhere which I will dig out when I get back home. Link to comment Share on other sites More sharing options...
Robbo Posted October 15, 2017 Share Posted October 15, 2017 I don't think there is a relay between microswitch and pump. Because, Lenny HB has added a relay on his new Hymer to reduce the current through the microswitch and thereby prevent pitting of the contact surfaces. Link to comment Share on other sites More sharing options...
aandncaravan Posted October 15, 2017 Share Posted October 15, 2017 If you suspect a micro switch is pitted, burnt or poor connection, operate another tap, just enough to hear the click, effectively doubling the 'power path'. If it makes a difference it indicates an issue. I added a relay when I added the Inline pump not because the current increase was significant but because the bigger contacts in the relay would reduce voltage drop and prolong the live of the Pressure sensitive switch which I also converted to. In reality the current is so low it won't make a lot of difference, unless there is an issue in the wiring/switches. However by converting to a pressure sensitive switch located right next to the pump, I removed all the wiring and the micro switches from the equation. The pressure sensitive switch is effectively put in the permanent 12v return/feed at the pump, when the pressure drops the switch activates and powers the pump. However, it is better to use the Water pump return/feed from the Control panel (can be found at the microswitch) so the pump can be isolated. In my experience, it isn't the power supply side to the pump which is the issue, but the lengthy wiring return 'to earth' method often employed, that goes from the pump through the switches (that often get wet at the taps and corrode) then back to the battery via the controlling switch, when this method of wiring is used. Obviously the adoption of a Pressure sensitive switches means you don't need Taps with micro switches, increasing your choice when it's replacement time. Picture attached of the Pressure sensitive switch I used. On Rimor and other vehicles that use the Arsilicii systems, problems with the Water are generally down to the remotely controlled NSA 1.0 Water Pump Node. Link to comment Share on other sites More sharing options...
Guest pelmetman Posted October 15, 2017 Share Posted October 15, 2017 StuartO - 2017-10-13 7:33 AM My B Class, 2006, Hymer has a submersible water pump, dual impeller, which lacks umph, especially for showering. I have replaced it with a new same type and it does perform as well as it's ever done. Can anyone suggest a better type of pump, to deliver a higher flow rate? We have a Shurflow, and have replaced it once in 27 years about 6 years ago. In the Carlight we've bought it has two systems, the traditional tugger water barrel with a submersible pump, and a onboard tank with a Shurflow. The first time we used the van and as we were a long way from the tap I used the tugger barrel.......I thought there was something wrong with the pump the flow rate was so poor .......But according to my Tugger brother it was normal 8-) ........ Managed to fill the onboard tank to try out the Shurflow and it was perfect pressure, plus the Carlight has domestic size taps ;-) ........ Link to comment Share on other sites More sharing options...
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