HymerVan Posted July 29, 2013 Share Posted July 29, 2013 Took the van away for a short trip at the weekend. The water systems had been drained down when van was last out and refilled again on site. On trying to bring water back up to taps/ fill hot water found pump was pumping air and a minute amount of water through the system. It is a diaphram pump. Problem cured by a kind site warden (yes they do exist !!) disconnecting the pump and then pumping out the air allowing water to follow behind it. I now know how to cure the problem should it recur but I am interested in any advice as to what would have caused it. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted July 29, 2013 Share Posted July 29, 2013 When refilling ours after a full "drain down", I usually find that just opening each tap in turn and "bleeding" it through until the water runs "smoothly", is all that it takes to "prime" our system. I may well've been lucky but I've never had to remove any pipes or disconnect the pump...... Although having said that,maybe there's a slight "leak", causing air to get in?..or maybe it's "siphoning" back out through the pump?...maybe..?:-S (..I'm sure a certain someone will be along soon, with links to websites and/or previous discussions ;-) ) Link to comment Share on other sites More sharing options...
Tracker Posted July 29, 2013 Share Posted July 29, 2013 How best to say this - the short answer is poorly designed systems and people? It often occurs when water does not flow evenly uphill. Complex and multi jointed pipes as in a van often run partly downhill as well as uphill as they meander to the taps. That allows the first flow of water to flow by gravity instead of being pushed by the pump which can allow air pockets to form in the high points and it is these air pockets which conspire to cause an airlock. The air pockets can't escape by rising as they are already at a high point and you can't pump air with a water pump so the presence of the air bubble mid pipe prevents the water on either side from joining up and becoming continuous. Once the pipes are full of water air pockets should not reform - unless air is getting into the system somewhere - or you run out of water - because the water in the pipe is held in place by the pump pressure, the vacuum it creates for itself by being a continuous stream and the weight of water from the tap downwards. Not a very scientific answer I know, but then I ain't a very scientific bloke, and I know it sounds daft and it is daft but there it is - daft or not! A good way to prevent it happening is to not switch the pump on until the tank is at least half full and without a hose running into it creating turbulence and aerated water and then open all the taps prior to switching the pump on. Doesn't always work but is well worth a try. Link to comment Share on other sites More sharing options...
HymerVan Posted July 29, 2013 Author Share Posted July 29, 2013 Yes normally the air will come out of the tap with the water following behind after a short time of running the pump by opening the taps (one each in the kitchen and washroom) but this time the pump would not push water through the system (as evidenced by the sight glass having no water in it ) despite there being plenty water in the tank and running the pump for several minutes. Like you I have not had an airlock before in ten years of motor-homing, which is why I am interested in ascertaining if there is a preventable cause. Link to comment Share on other sites More sharing options...
Tracker Posted July 29, 2013 Share Posted July 29, 2013 One quick and easy method of dispersing an airlock is to open the tap and with the pump on suck on the tap spout - or use a hose connected to it - to help the water along - but mind you don't get a face full of water when it releases as it tends to come with a rush! Link to comment Share on other sites More sharing options...
nowtelse2do Posted July 29, 2013 Share Posted July 29, 2013 I use to turn the tap on that was furthest from the pump first then switch on the pump. Keep all the other taps closed, once you get water through the first one work your way back starting with the next furthest tap. Close each tap after bleeding it. Worked for me. If sucking it through as Rich recommends, you will probably end up with Typhoid :-D Dave Link to comment Share on other sites More sharing options...
Tracker Posted July 29, 2013 Share Posted July 29, 2013 nowtelse2do - 2013-07-29 6:11 PM If sucking it through as Rich recommends, you will probably end up with Typhoid :-D Dave Why? It's treated and chlorinated tap water - aka drinking water! You may well prefer Typhoid tea bags but we find that Morrisons own label tea bags are just as good and cost less! Link to comment Share on other sites More sharing options...
nowtelse2do Posted July 29, 2013 Share Posted July 29, 2013 Tracker - 2013-07-29 7:01 PM nowtelse2do - 2013-07-29 6:11 PM If sucking it through as Rich recommends, you will probably end up with Typhoid :-D Dave Why? It's treated and chlorinated tap water - aka drinking water! You may well prefer Typhoid tea bags but we find that Morrisons own label tea bags are just as good and cost less! Its whats in the pipes that would worry me after a lengthy lay up. Morrisons..!!!!! you must be rich Rich. We have one opening here on the 5th August......will go in and get a paper then have a snoop round, see if we can afford any tea bags. Dave Link to comment Share on other sites More sharing options...
Tracker Posted July 29, 2013 Share Posted July 29, 2013 nowtelse2do - 2013-07-29 9:31 PM Morrisons..!!!!! you must be rich Rich. We have one opening here on the 5th August......will go in and get a paper then have a snoop round, see if we can afford any tea bags. Dave Used to be well off - but marriage soon cured that problem - so now I have no money worries - well none to worry about anyway! I have spent so much having fun with fast cars, fast women and slow motorhomes - and the rest of the cash I just frittered away! Link to comment Share on other sites More sharing options...
Iain Strachan Posted July 29, 2013 Share Posted July 29, 2013 Maybe try filling the tank with the tap open and the pump off. But I like Trackers Sucking idea better! Link to comment Share on other sites More sharing options...
Tracker Posted July 30, 2013 Share Posted July 30, 2013 Iain Strachan - 2013-07-29 11:16 PM Maybe try filling the tank with the tap open and the pump off. But I like Trackers Sucking idea better! Thanks Iain - I always was a sucker for a few kind words! As the tank is the lowest part I don't quite follow how filling the tank with the pump off and taps open will help - but I am always happy to bow to your superior knowledge if you do know how/why!! However I suspect that in the OPs case, because he lives in the North of Scotland the van has not yet fully thawed out from last winter! Link to comment Share on other sites More sharing options...
HymerVan Posted July 30, 2013 Author Share Posted July 30, 2013 Van has been in Hungary Croatia Germany France Austria Italy Switzerland Slovenia so far this year (as well as Scotland where it was 25c on Friday ) so actually thawing out is not an issue. Link to comment Share on other sites More sharing options...
docted Posted July 30, 2013 Share Posted July 30, 2013 I am with Tracker here but I would suggest a dash of whisky before the water to ensure all germs killed off. :D Link to comment Share on other sites More sharing options...
Tracker Posted July 30, 2013 Share Posted July 30, 2013 docted - 2013-07-30 3:12 PM I am with Tracker here but I would suggest a dash of whisky before the water to ensure all germs killed off. :D Obviously a Sassenach - only a non believer would pollute whiskey with water of any kind! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 31, 2013 Share Posted July 31, 2013 HymerVan - 2013-07-29 5:20 PM Yes normally the air will come out of the tap with the water following behind after a short time of running the pump by opening the taps (one each in the kitchen and washroom) but this time the pump would not push water through the system (as evidenced by the sight glass having no water in it ) despite there being plenty water in the tank and running the pump for several minutes. Like you I have not had an airlock before in ten years of motor-homing, which is why I am interested in ascertaining if there is a preventable cause. I'm not convinced this is an airlock issue. A diaphragm pump has a lot of 'suck' and, even when the fresh-water tank is beneath the motorhome (as is the case with your East Neuk Fifer) the pump should normally be able to lift the water without much difficulty. It's likely that your Fifer has a non-return valve 'upstream' of the pump (ie. between the pump and the water pick-up in the fresh-water tank) to limit water draining back into the tank. If that valve remained closed after you'd refilled the water tank, the pump would have been unable to suck water from the tank. Even a partially-open valve might offer sufficient resistance to water-flow to prevent the pump lifting the water. Disconnecting the pump from the water system on its 'downstream' side (which I understand is what the site warden did) would maximise the pump's 'sucking' capability allowing it the maximum chance to fully open a closed (or partially-closed) non-return valve. An air-leak (as mentioned by pepe63) in the system upstream of the pump (eg. inside the water tank), or on the input side of the pump itself, could well prevent the pump from lifting water from the tank. However, if there were such an air-leak (and you eventually managed to get water through to the taps), one would expect a lot of spitting and spluttering at the taps as air+water was expelled. If that's not happening, there's no 'upstream' air-leak. If a sticking non-return valve was the cause of your problem, it could be a one-off occurrence. If it happens again, I suggest you try replacing the non-return valve. Of course, if a Fifer does not have a non-return valve, then you can ignore most of what I've said above!! Link to comment Share on other sites More sharing options...
gwyn Posted July 31, 2013 Share Posted July 31, 2013 We usually find jumping up and down in the van does the trick or driving a few miles over bumpy roads....easy in this country of potholes! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 31, 2013 Share Posted July 31, 2013 It would also be worth confirming that the filter-gauze in the water pump's 'sight glass' is clean. A mucky gauze will seriously reduce a pump's ability to suck water. Link to comment Share on other sites More sharing options...
docted Posted July 31, 2013 Share Posted July 31, 2013 Water is what you add to a single malt whisky, note spelling please, to bring out the aromatics. The other stuff with an "e" in the spelling is a pollutant. :-S BTW born in Glasgow sort of makes me Scottish plus I have always stayed here so I reckon that confirms it. Call me a sassenach again and I know where I'll ram my claymore (!) :D Link to comment Share on other sites More sharing options...
HymerVan Posted August 6, 2013 Author Share Posted August 6, 2013 Away last weekend same problem again. Phoned East Neuk who after some diagnosis said that they were pretty sure the diaphragm on the pump had failed. They said that under normal circumstances pump reliably self primes. The pump is a Fiamma 8 which looks well engineered and robust. Agree that ENC would send a new pump which I could fit myself to save a trip to Anstruther. They immediately sent pump out and I have now fitted it and system seems to be working fine. Appears not to have been an airlock at all. Link to comment Share on other sites More sharing options...
Tracker Posted August 6, 2013 Share Posted August 6, 2013 HymerVan - 2013-08-06 11:37 AM Away last weekend same problem again. Phoned East Neuk who after some diagnosis said that they were pretty sure the diaphragm on the pump had failed. They said that under normal circumstances pump reliably self primes. The pump is a Fiamma 8 which looks well engineered and robust. Agree that ENC would send a new pump which I could fit myself to save a trip to Anstruther. They immediately sent pump out and I have now fitted it and system seems to be working fine. Appears not to have been an airlock at all. Great news - so glad you've sorted it. A split diaphragm can cause all sorts of problems! Funnily enough the only pump that I ever had a problem with was a Fiamma many moons ago and the dealer replaced it with a Shurflo with which I have never had any problems with many over many years. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted August 6, 2013 Share Posted August 6, 2013 Good to hear you've sorted it.. ;-) Do they want the faulty pump back?...because I just wonder if it's worth looking at "fixing" it and keeping as a spare, "just in case"...? :-S http://www.marcleleisure.co.uk/store/-c-330_406.html Link to comment Share on other sites More sharing options...
HymerVan Posted August 6, 2013 Author Share Posted August 6, 2013 They have not asked for it but it isn't obvious what is wrong with it !, Link to comment Share on other sites More sharing options...
HymerVan Posted August 6, 2013 Author Share Posted August 6, 2013 They have not asked for it but it isn't obvious what is wrong with it !, Link to comment Share on other sites More sharing options...
Tracker Posted August 6, 2013 Share Posted August 6, 2013 HymerVan - 2013-08-06 1:00 PM They have not asked for it but it isn't obvious what is wrong with it !, It may well be just a tiny pin prick of a hole in the diaphragm which you might never locate as it probably only manifests itself when it is stretched and under pressure? Link to comment Share on other sites More sharing options...
HymerVan Posted August 15, 2013 Author Share Posted August 15, 2013 Away for long weekend and pump and water system worked perfectly. Although there probably never was an airlock thanks for all contributions nonetheless. Link to comment Share on other sites More sharing options...
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