Air in water system/Pump?

Discussion in 'Motorhome Chat' started by normanandsue, Nov 4, 2014.

  1. normanandsue

    normanandsue Funster

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    To avoid the risk of frost damage I drained down the water system but as I am going away tomorrow I have refilled the system. Despite the pump running there is no water flowing from the taps. Having read the manual it seems this could be due to air in the system/ pump. So after removing the shower head and opening the tap and turning off the pump I blew and sucked until I found water. Despite this the pump continued to run but no water flowed.
    I have had this problem before when we ran out of water and after a couple of days driving the system corrected itself and worked properly until it was drained down. The manual suggests to release air in the pump the pump should be given a good shaking whilst submerged in the tank. A great help when there is no advice as to how to access the freshwater tank!!!!

    My conclusion is air in the pump could one of you clever folk confirm this please?

    Also as it is this much trouble to refill after draining down I am seriously thinking of not draining down the system but leaving it filled with a low wattage heater on to prevent the pipes freezing up. The Truma boiler will automatically dump when temperature reaches 6 degrees and as long as the tank is not completely filled it is unlikely it will freeze solid and cause damage as their will be room for expansion, I also have a "heater" fitted to both tanks as part of a winterisation package. (My mh stands on the drive and is connected to mains)

    I have read all the threads about this and am convinced the right thing to do is to drain down, but as I intend to use the mh at least once a month over the winter period I could do without all this hassle.
     
  2. Bobndebs McKay

    Bobndebs McKay

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    You could try priming the system by removing the shower head, holding the hose high and pouring water down it until the whole line is full, then while still holding the hose up, run the pump and see if that primes it and bleeds the air out. I am given to understand that most pumps are self priming nowadays, but a bleed point in the line would be useful!! Good luck and please let us know for my own future reference how you get on.
     
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  3. Masman

    Masman Funster

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    Don't know how long you are trying to prime pump.but mine takes a good 5 minuites to get the water flowing properly.:whistle:I close all taps .then open one tap closest to pump.then when water runs freely slowly open hot tap to get rid of air in boiler. Then do same with other taps. I personaly would not leave water in tank if it looks like being realy cold.I don't think its the tank you have to worry about but the taps can split on some models.(y)
     
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  4. gozomike

    gozomike Funster Life Member Life Member

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    So driving it whilst switched on might work.
     
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  5. Theonlysue

    Theonlysue Funster Life Member

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    I have had an airlock once, so I drained all the water out and started agsin.
    my handbook says to open hot tap furthest from fresh water tank till water comes through. This may take a while as the hot tank holds approx 10 litres, so that is 10 litres if air that had to come out. You should feel the air coming out of the tap. Then close that and open the hot tap that is next furtherest away and work in that order. Then repeat with cold water tap.
    I empty and refill as required, as any ice damage could be expensive to repair.
    Good luck :)
     
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  6. normanandsue

    normanandsue Funster

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    Thanks Mike I will give it a try. Should I keep the pump running whilst I wait for the air to come through? My handbook warns of the danger of running the pump without water (I presume an air lock in the pump would mean the pump running "dry"?)
     
  7. normanandsue

    normanandsue Funster

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    Have tried running pump for 5 minutes with cold tap open; have tried running pump for 5 minutes with hot tap open. Still no water.
    Ran pump, opened sink tap and opened shower tap took off shower head and blew down pipe and air came out of sink tap, but no water.
    I am concerned that running the pump with no water coming through will ultimately damage the pump.
     
  8. Badknee

    Badknee Funster

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    Stick a hosepipe on the shower hose and see if you can get some water into the tank that way, if it arrives in the tank the pump must be full. (y)
     
  9. MikeD

    MikeD Funster

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    If it takes so long to prime the system then you must be sucking air into the water supply to the pump.

    My Autotrail also took a long time to prime and the dealer found out that the supply pipe into the water tank had a air hole (the centre of a pop rivet) in the feed line.

    I understand that a self tapper into the centre of the pop rivet cured the problem.

    But in my humble opinion if it takes so long to prime you must be sucking some air from somewhere or your pump is not sucking at all. (y)
     
  10. vin0114

    vin0114 Funster

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    I had the same problem earlier this year, I had opened the hot taps pror to filling but made the big mistake of forgetting to turn the pump on. Eventually had to dump the water and refilled properly without problem.
     
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  11. Masman

    Masman Funster

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    I don't know how old your pump is.My pump is a surflow.I had a similar problem,Turned out to be the diaphragm in pump.It cost aprox 18 pounds for parts.Its a easy repair.If you Google it you will find some info.
     
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  12. Wickolad

    Wickolad Funster

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    I know this suggestion may appear totally unrelated but I think in principle should achieve same result.
    Having had my previous domestic central heating system drained down at home, the pump could not get rid of an airlock when trying to refill. The plumber connected the garden hosepipe to the downstairs radiator and used mains pressure water to push out the airlock by opening the bleed screws in the all radiators and it was successful.
    Using this principle, could you not open all taps in hot/cold positions including shower. Then using garden hose on relatively low tap setting so as not applying excessive pressure, and rubber bung of sorts to form a decent seal at the water filling point force water into the tank, (you may have to temp block the overflow pipe) thereby forcing water throughout the hot/cold pipe system including pump and driving out the airlock.
    If you then get water through all taps and still the pump doesn't do what it should, then this may point to the diaphragm as previously mentioned.
    It is almost as was suggested with the shower hose but using mains pressure to expel the airlock. Main thing is to not have garden hose tap set too high, I think.
    Hope this does the trick for you.
    Lance.
     
  13. Wickolad

    Wickolad Funster

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    Just an afterthought as well, only because I've actually done this myself but I'm not in anyway suggesting you may be nearly as daft as what I felt at the time. Did you remember to close the water dump valve for your heater system. When I dump mine to drain the system I always leave it open in case of anteater left in freezing, it allows expansion and no pressure fractures to pipes or fittings. I have forgotten to close this a couple of occasions and wondered why the water wasn't coming through the taps when I came to refill the system. I doubt I'm the only one to have ever done this though.
    Lance
     
  14. gozomike

    gozomike Funster Life Member Life Member

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    Is the pump submerged in the tank or an external one, reading your first post I assume the former.

    If the pump is running dry I would limit the time it is on which you indicate is what you have been doing.
     
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  15. golly

    golly Funster

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    Why do you keep anteaters in the fridge? Do the RSPCA know about this :roflmto:
     
  16. Bobndebs McKay

    Bobndebs McKay

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    If its a vane pump then there will not be a diaphragm to worry about! I would establish the type of pump you have, position etc and then as Wickolad suggests look at dump valve etc. Let us know how it goes! Good Luck
     
  17. Wickolad

    Wickolad Funster

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    Hahaha, well spotted. Pre- emptive text. Isn't it just great. Teach me to check before posting.
    Can't get away with anything on here haha.
     
  18. normanandsue

    normanandsue Funster

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    What I might have done wrong!!!!!!!!!:(
    • I switched the pump on whilst filling the tank
    • I left the taps open having failed to close them after draining the tank
    I have drained the tank and am now refilling it with pump off and taps closed.
    I will let you know what happens.
    If the problem persists then it seems as if sucking on the shower hose with pump on and tap open is the only solution.
    Have never had a Whale system before and never had these problems either
     
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  19. normanandsue

    normanandsue Funster

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    After 15 minutes of sucking and blowing I manage about a couple of mouthfuls of water but none flowing from the taps.
    It does seem as if the air is in the pump which the manual says can be shaken for it to be expelled but as my Freshwater tank is a sealed unit that is not going to be possible. I had this problem once before and after a couple of days it sorted itself, so I am hoping after our outing today that might happen again.

    I will never buy a mh with a whale water system again :devil::devil::devil:
     
  20. GWAYGWAY

    GWAYGWAY Funster

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    Is the dump valve on the trauma open???
     
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