mark hinde Posted August 12, 2011 Share Posted August 12, 2011 I have a 10 year old Swift Kon Tiki, fitted with a Shureflo pump and Truma Heater. As I drain down the system everytime we get home, I refill it every time we go away. My problem seems to be we forever get air in the system and the taps gurgle and splutter (funny when it happens to the wife but I actually got a soaking last time!!) Can't see any sign of a leak and the pump doesn't switch itself on every now and then so I assume the pressure stays in the system, so I can't work out where the air is coming from. Any Ideas? Link to comment Share on other sites More sharing options...
Colin Leake Posted August 12, 2011 Share Posted August 12, 2011 We had this problem and traced it to the fact that the fresh water drain valve was not sealing properly. It held the water in but allowed air to be sucked in when the pump was operated. Fitted new valve for a total cure. Hope his helps. It took me ages to find the cause. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 12, 2011 Share Posted August 12, 2011 Check that you have not got an air-leak well 'upstream' of the water-pump. For example, at the fitting where the water-hose joins to the fresh-water tank. If there's (say) a small split in the fitting on the INSIDE of the tank, there will be no sign of a water leak but air will enter the system. Link to comment Share on other sites More sharing options...
Keith T Posted August 12, 2011 Share Posted August 12, 2011 When you refill your fresh water tank, leave all taps open (H&C), with the pump off, and this should remove any air from the system. We've had quite a few probelms on various motorhomes with this, and generally you only need to do this the first time you refill the tank. However, we have had 'gurgle' problems and following this procedure each time has helped. What I tend to do is to leave the taps open initially, as suggested above, and then whilst still filling the tank (assuming you can leave the hose in the external filler) turn the taps off, then put the 12v pump on, and check each tap is operating OK. Alternatively, depending on your system, the water may be draining back into the tank when you turn the taps off, and therfore each time you turn them on again, some air seem to get in - we had a non-reveral valve (I think thats; what they called it) fitted to overcome this. Hope this is of some help - it's often one of these trial and error situations until you find the cause. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 13, 2011 Share Posted August 13, 2011 Keith T - 2011-08-12 7:54 PM When you refill your fresh water tank, leave all taps open (H&C), with the pump off, and this should remove any air from the system. We've had quite a few probelms on various motorhomes with this, and generally you only need to do this the first time you refill the tank. However, we have had 'gurgle' problems and following this procedure each time has helped. What I tend to do is to leave the taps open initially, as suggested above, and then whilst still filling the tank (assuming you can leave the hose in the external filler) turn the taps off, then put the 12v pump on, and check each tap is operating OK. Alternatively, depending on your system, the water may be draining back into the tank when you turn the taps off, and therfore each time you turn them on again, some air seem to get in - we had a non-reveral valve (I think thats; what they called it) fitted to overcome this. Hope this is of some help - it's often one of these trial and error situations until you find the cause. It's a "non-return valve", but it really should only be necessary when the motorhome has a 'submerged' pump (ie. the pump is immersed in the fresh-water tank). The non-return valve prevents water siphoning back into the fresh-water tank through the submerged pump and, normally, the valve will be attached to (or integrated in) the water-pump. I'm surprised your Burstner's water system (apparently) didn't have a factory-fitted non-return valve as, without one, siphoning is pretty much inevitable. With a water system like Mark's Kon-Tiki's, a non-return valve should not be required as the Shurflo diaphragm-type water-pump should prevent siphoning. The procedure for filling a Truma Ultrastore boiler can be summarised as follows: 1. Close water-system drain valve(s) and taps. Ensure water-pump is switched off. 2. Open a hot tap fully. 3. Switch on water-pump. Leave hot tap open to let air escape while the boiler is filling. The heater is filled when water flows smoothly from the tap. Close tap. (Obviously, once the boiler is filled, there will be a need to bleed air from the rest of the system by opening/closing the other taps successively until water flows smoothly from each.) Lots of motorcaravanners seem to experience problems getting air out of their vehicle's water system, but the only difficulty I've ever had was when the water-hose that fed the pump loosened where it was connected to the water-tank. Until I noticed this (eventually the hose became disconnected and water poured on to the tank's upper surface), the taps spat badly whenever they were turned on. It normally takes me about 10 minutes to fill and 'bleed' my Hobby's water-system and, once this has been done, the taps won't subsequently spit. I believe George Collings once reported in MMM's "Interchange" section that the Shurflo pump in his motorhome began to let air in through the pump-head assembly, so that's another possibility. Repair kits are available for Shurflo pumps, though - for a 10-years-old pump - if there's a significant mechanical fault, replacing the complete pump might make better sense. Although diaphragm-type pumps can produce serious 'pulsing' at the taps (which can be addressed by installing a surge-damper), it should be possible to distinguish between pulsing and air/water being expelled from the tap. If air/water is coming out, then air MUST be getting in somewhere and (if there's no sign of a water leak and the pump isn't switching itself on to maintain pressure within the water system), logically, the air must be getting in before the water-pump's outlet. Link to comment Share on other sites More sharing options...
mark hinde Posted August 15, 2011 Author Share Posted August 15, 2011 Thanks for all the good advice. Air getting in upstream sounds favourite as on inspection of the cold water tank I notice a lot of what can only be described as "gunk" around the tank outlet pipe. Obviously a problem in the past and looks like a tank out job to repair properly. Many thanks once again and to Derek and Keith for the filling procedure as I have to admit I have always filled the tank first, turned the pump on then opened the taps. Mark H Link to comment Share on other sites More sharing options...
Minstrel Posted September 16, 2011 Share Posted September 16, 2011 We recently came back from more than three weeks in France. We had this problem. Each time we wanted to have hot water, I checked that the air was all out of the system by opening hot water taps fully. Not a scrap of use, it always spluttered. the pump runs for a long time when in use and sounds breathy. Chris had a look at the shurflo pump and can see the smallest of cracks in the clear filter on the end. A replacement is about £11.25 inc postage so we'll try that. Link to comment Share on other sites More sharing options...
George Collings Posted September 18, 2011 Share Posted September 18, 2011 Spluttering due to air in the water system can be due to air getting in on the suction side of the pump. Here is another thought on the subject. We have just got back from three weeks in France. Water consumption seemed to suddenly jump and while filling up from a high pressure supply we noticed considerably more than normal water spilling from the overflow at the top of the tank. A trip up the leveling blocks gave room to get my hand over the top of the tank to find the bayonet fitting access hatch cover was missing. Although we carry a separate supply of drinking water the prospect of washing, clothes and ourselves with water contaminated with road filth did not appeal Clive and Jan Mott G were joined us on an aire the same day. Clive and I set to using a suitable kerb and blocks to give clearance we extracted the tank and sacrificed a plastic bread board to make a replacement cover. The tank had never been down so I presume some sort of overflow was incorporated into the cover. The tank had four buttons with approx 1mm dia breather holes let into the top corners so I made no further venting provisions intending to fill the the tank until it overflowed at the filler. Of course nothing ever goes quite according to plan. The supply fitting at the bottom of the tank broke while wrestling the hose off and the wiring to the water gauge had to be cut but I carry crimp on electrical connectors . Clive sped of to the local plumbers merchants to find a replacement while I operated on the bread board. The new brass fitting was designed for ordinary garden hose rather than the thick wall one on the 'van but a hacksaw soon got over that problem although the length of brass to fit the hose over was a tad shorter than ideal. A mornings efforts saw the tank back in place and refilled with no leaks. However here is the punch line. Since then we have had the splutters presumably air is entering the system. Two possiblities spring to mind. (a) Despite there being no apparent water leakage air is getting in via the new brass to hose connection or (b) even elsewhere because the small vent buttons into the tank are inadeguate to keep up with the pump causing a low vacuum increasing the chances of air getting in. It might even be (a) and (b) in combination. Could it be that inadequate tank venting is a contributory factor is some cases of spluttering. Tomorrow I will check if leaving the filler cap off improves matters. Watch this space. Link to comment Share on other sites More sharing options...
George Collings Posted September 18, 2011 Share Posted September 18, 2011 Tried the system with the filler cap off. Short splutter until air purged from system then a nice smooth flow. Too early to be sure but perhaps in my case it is a case of lack of tank venting. Sorry about the punctuation or rather lack of it in last nights posting. I plead lack of eddicaton and time of night your worships. Link to comment Share on other sites More sharing options...
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