david lloyd Posted January 10, 2016 Share Posted January 10, 2016 Hi everyone, Our previous IH panel van water pump often cycled a. Couple of times, particularly at night. We had them check the van for leaks a couple of times and nothing was found. The pump on our new van started to do the same only more frequently on the way down here to Spain. Initially I thought it may just be the same thing but one morning woke to find water running from under the kitchen cupboards. Further inspection showed that some if the jubilee clips joining the newly fitted water filter to the cold supply were not tight and dripping water was the result. These have been tightened and I have been checking daily to ensure there are no further leaks. However, the pump still cycles for just a second or so, especially during the evening or at night. I have traced all the water pipe work and found no other leaks. My only thought is because we tend to leave the hot water on overnight this causes the water in the heater to expand and probably lose some through the overflow. Them during the evening/night when it cools slightly the pump runs to top up the heater when the level falls slightly due to the cooling. I am not sure if this would be the cause or if anyone else finds their pump does the same thing? David Link to comment Share on other sites More sharing options...
Robbo Posted January 10, 2016 Share Posted January 10, 2016 My shurflo pump tends to cycle occasionally, which is probably fairly normal. At one time it used to cycle frequently with water dripping from the underside of the van. My water system uses a lot of plastic T- pieces to divert water off to the sink, bathroom etc. It was found that one of the T-pieces was leaking and issuing a fine spray of water. The plastic T-piece was renewed and solved the problem. However, the cycling started again and this was tracked down to the plastic filter bowl on the inlet to the pump. I unscrewed the bowl and checked the rubber O-ring. Gave it a clean and lubricated with silicone spray. Replaced and everything OK once again. Beware, the plastic bowl can crack if left over winter in freezing temperatures with water still in the bowl. Some remove the filter bowl during winter conditions. Link to comment Share on other sites More sharing options...
rolandrat Posted January 10, 2016 Share Posted January 10, 2016 David, are you sure that it's the pump? Could it be some other electronic circuit breaker that is energising for no apparent reason. I mention this because an IH that I once owned did something similar and I put it down to the electronics that controlled the awning. It could happen at any time and noticeable when parked up. Link to comment Share on other sites More sharing options...
PJay Posted January 10, 2016 Share Posted January 10, 2016 We always switch the pump off when not in use. Never leave it on at night, as the green light that shows it on, is very bright ! PJay Link to comment Share on other sites More sharing options...
laimeduck Posted January 10, 2016 Share Posted January 10, 2016 Ours did this so I wired in a simple 12v switch with a very bright warning bulb near the tap which is only on when we want to use the pump. Problem solved. Link to comment Share on other sites More sharing options...
George Collings Posted January 10, 2016 Share Posted January 10, 2016 After a few years the flexible valves in the pump can begin to leak slightly and the water pressure drops far enough to trigger the pump long enough to restore pressure, Initially the cycle is very long but eventually it becomes very short. Parts to restore the pump are available but are not that much cheaper than a complete unit along with a motor. I ddi mine a bout three years ago and retain the old motor as a spare. Link to comment Share on other sites More sharing options...
Tracker Posted January 10, 2016 Share Posted January 10, 2016 It used to sometimes be caused by the ingress of air in the suction side of the pump, ie the pipework between the pump and the tank and for vans fitted with a shurflo type pump even a slightly loose filter bowl, or a not fully tightened joint could be all that was needed to allow a tiny amount of air into the system without allowing any water out and these can be hard to find. Link to comment Share on other sites More sharing options...
Willy Wonka Posted January 10, 2016 Share Posted January 10, 2016 If it's anything like this water pump it will probably be air getting in the system from the pipe work, the glass cover may not be screwed down tightly enough or the rubber seal may need cleaning or replacing. If all that fails to solve the problem it's almost certainly knackered and needs replacing! Link to comment Share on other sites More sharing options...
Willy Wonka Posted January 10, 2016 Share Posted January 10, 2016 If it's anything like this water pump in the video below it will probably be air getting in the system from the pipe work, the glass cover may not be screwed down tightly enough or the rubber seal may need cleaning or replacing. If all that fails to solve the problem it's almost certainly knackered and needs replacing! Link to comment Share on other sites More sharing options...
George Collings Posted January 10, 2016 Share Posted January 10, 2016 The majority of older vans had Shurflo pumps as do many current models. Air leaks on the suction side of the pump in should not reduce pressure on the delivery side where the pressure sensor is located. Suction side leaks delay or even prevent delivery and can cause air locks and spluttering etc. There are two main forms of caravan domestic plumbing sytems. The type we are talking about where the the pump is triggered by a drop in pressure as water is used and the system is always under pressure unless the electrical supply to the pump is off. The other system switches the pump via a micro switch in the taps so the system is only pressurised when water is being used. Leaks are less of a problem but water and electricity are poor bedfellows and reliability can suffer. Fully immersed pumps sat in the water tank avoid the problems of air leaks but mix of water/sparks issue still applies Link to comment Share on other sites More sharing options...
david lloyd Posted January 11, 2016 Author Share Posted January 11, 2016 George Collings - 2016-01-10 7:26 PM The majority of older vans had Shurflo pumps as do many current models. Air leaks on the suction side of the pump in should not reduce pressure on the delivery side where the pressure sensor is located. Suction side leaks delay or even prevent delivery and can cause air locks and spluttering etc. There are two main forms of caravan domestic plumbing sytems. The type we are talking about where the the pump is triggered by a drop in pressure as water is used and the system is always under pressure unless the electrical supply to the pump is off. The other system switches the pump via a micro switch in the taps so the system is only pressurised when water is being used. Leaks are less of a problem but water and electricity are poor bedfellows and reliability can suffer. Fully immersed pumps sat in the water tank avoid the problems of air leaks but mix of water/sparks issue still applies Thank you to everyone. George, I haven't checked inside the water tank located beneath the forward facing belted seats but thought mine is a submersible pump as I haven't found it anywhere else since looking for leaks in the pipe work. For information, the new van is a Chausson Welcome 717GA and only 6 months old so any seals etc should still be serviceable. I certainly seem to have rectified the leaks around the joints to/from the water filter and have only occasionally heard the pump run momentarily since, usually at night. David Link to comment Share on other sites More sharing options...
david lloyd Posted January 12, 2016 Author Share Posted January 12, 2016 Aha! Seek and he shall find. The shurflo diaphragm pump is located inside a boxed in section at the 'L' shape of the front dinette. I have checked all round this, including the filter bowl, and there is no sign of a leak there. More mysteriously, I turned the hot water off today and it has still cycled momentarily. Reading through the shurflo manual though it does say that such cycling can be caused by various things, amongst them are the fitting of water filters or purifiers which may cause back pressure. So, could this be the cause? There is a part in the installation instructions that indicates the cycling rate can checked and, if it is not within normal parameters, adjusted. But this seems a little out of my depth and if this could solve it I would need to get a professional to do it at service time. David Link to comment Share on other sites More sharing options...
Derek Uzzell Posted January 12, 2016 Share Posted January 12, 2016 david lloyd - 2016-01-10 2:39 PM ...However, the pump still cycles for just a second or so, especially during the evening or at night. I have traced all the water pipe work and found no other leaks. My only thought is because we tend to leave the hot water on overnight this causes the water in the heater to expand and probably lose some through the overflow. Them during the evening/night when it cools slightly the pump runs to top up the heater when the level falls slightly due to the cooling. I am not sure if this would be the cause or if anyone else finds their pump does the same thing? David I believe a Welcome 717GA’s air/water heating system will be based on a Truma “Combi” appliance. A motorhome’s water system downstream of the water pump (ie. the pressurised part of the system between the pump and the water-heater and taps) is ‘closed’ and this will be true irrespective of the type of water pump. A closed pressurised water-system cannot include an overflow. It’s sometimes believed that the elbow fitting on the hot-water outlet of a Truma combination air/water heater is some sort of overflow and/or pressure release valve, but it’s actually a breather ("aeration valve" in current Truma-speak) that lets air into the heater ’s water reservoir when the reservoir is being drained automatically or delliberately. Occasional short-duration operation of the water pump may well occur in the type of situation you’ve described, when hot water within the Truma heater cools down causing a consequential small pressure-reduction within the closed system. Assuming that there are no symptoms of an air-leak ‘upstream’ of the water pump (eg. spitting and spluttering from the taps), a very small water leak downstream of the pump would alsol result in the occasional cycling you’ve mentioned. A poor seal on the system’s drain-valve or a tiny leak from one of the hose connections could do it. The water reservoir in my Herald’s Truma heater developed a minuscule crack in a weld. The crack used to open up when water was heated and close when the water cooled. The Herald’s SHURflo pump used to cycle very briefly now and again as a result and I only identified the reason when the problem worsened enough for the water leakage to become obvious. (I’m sure that’s not the case with your heater - I’ve just mentioned it as an example of how difficult it can be sometimes to pin down the cause of momentary pump cycling.) As Robbo said earlier, if your pump only cycles occasionally and there are no signs of water leakage, it’s probably nothing to be concerned about. Link to comment Share on other sites More sharing options...
david lloyd Posted January 13, 2016 Author Share Posted January 13, 2016 Derek Uzzell - 2016-01-12 2:04 PM david lloyd - 2016-01-10 2:39 PM ...However, the pump still cycles for just a second or so, especially during the evening or at night. I have traced all the water pipe work and found no other leaks. My only thought is because we tend to leave the hot water on overnight this causes the water in the heater to expand and probably lose some through the overflow. Them during the evening/night when it cools slightly the pump runs to top up the heater when the level falls slightly due to the cooling. I am not sure if this would be the cause or if anyone else finds their pump does the same thing? David I believe a Welcome 717GA’s air/water heating system will be based on a Truma “Combi” appliance. A motorhome’s water system downstream of the water pump (ie. the pressurised part of the system between the pump and the water-heater and taps) is ‘closed’ and this will be true irrespective of the type of water pump. A closed pressurised water-system cannot include an overflow. It’s sometimes believed that the elbow fitting on the hot-water outlet of a Truma combination air/water heater is some sort of overflow and/or pressure release valve, but it’s actually a breather ("aeration valve" in current Truma-speak) that lets air into the heater ’s water reservoir when the reservoir is being drained automatically or delliberately. Occasional short-duration operation of the water pump may well occur in the type of situation you’ve described, when hot water within the Truma heater cools down causing a consequential small pressure-reduction within the closed system. Assuming that there are no symptoms of an air-leak ‘upstream’ of the water pump (eg. spitting and spluttering from the taps), a very small water leak downstream of the pump would alsol result in the occasional cycling you’ve mentioned. A poor seal on the system’s drain-valve or a tiny leak from one of the hose connections could do it. The water reservoir in my Herald’s Truma heater developed a minuscule crack in a weld. The crack used to open up when water was heated and close when the water cooled. The Herald’s SHURflo pump used to cycle very briefly now and again as a result and I only identified the reason when the problem worsened enough for the water leakage to become obvious. (I’m sure that’s not the case with your heater - I’ve just mentioned it as an example of how difficult it can be sometimes to pin down the cause of momentary pump cycling.) As Robbo said earlier, if your pump only cycles occasionally and there are no signs of water leakage, it’s probably nothing to be concerned about. Thank you Derek. I am reassured by your answer. I cannot trace any further signs of a water leak now that I have finally found the pump! In fact, I did turn off the water heater yesterday and, although it did cycle once or twice during the day/evening - presumably whilst cooling down - it has not recurred. I have the heater back on now and, curiously, the pump has not cycled again yet. I am also grateful for the explanation of the clear tubing exiting from the heater (it is in fact a Truma D6 - diesel/electric type) as I had wrongly presumed it to be an expansion or relief valve. So, it looks like I can relax now. I will, of course, maintain watch for signs of water leaks but it does seem that the initial cause has been rectified and what remain (any occasional cycling of the pump) is probably normal. Thank you and to everyone else who contributed. David Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.