My dump valve(!)

Discussion in 'Motorhome Chat' started by TDH, Jan 24, 2011.

  1. TDH

    TDH Funster

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    Sorry for the rather vulgar thread title. Being new to technicalities like water heaters (warm water in the original Rosabella was delivered via a kettle) I've got a couple of daft questions about my Truma water heater.
    1. Does the dump valve go straight to the outside? There's an extension pipe coming from the little hole in the bottom of the wardrobe (where the heater is situated) but its bent up and over the chassis and I can't see how water is supposed to come out. I've assumed that that is wrong and now the valve emits straight to the outside world - is that OK (actually, as I'm writing this I'm realising that it's a really stupid question!)
    2. The reason I was investigating it was that with the lever of the dump valve in the horizontal position there was water seeping up from beneath the valve. I've come to the conclusion that when the system was under pressure (ie the water was being pumped) the valve was weeping and the water was unable to escape because of the forementioned bent pipe. Is the valve likely to weep with the lever in the horizontal and the taps on? I've noticed that if I push the lever slightly beyond the horizontal it opens.
    Soz if these are obvious!

    T
     
  2. Terry

    Terry Funster

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    Not sure I understand your post right :Rofl1: but the dump valve usually goes straight onto the floor outside :thumb: If your has been extended that could be why it is bent over the chassis - but why ?drop the pipe so the water goes onto the floor - it is a safety devise to dump the water out of the boiler to stop it freezing- it then needs resetting, some clip a peg under it to hold it closed and stop water flooding out.Once reset it should hold it shut on it own.
    terry
     
  3. MikeandCarolyn

    MikeandCarolyn Read Only Funster

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    Is this RED lever ??
    I ask cos there is one just to the left of our 'dump valve' and I'm not sure of it's use myself.
    Yes-the dump valve should stay closed after you reset it-but only until the temperature drops below about 5-8deg.Hence the use of a peg or clamp to keep it shut and avoid waking up to an empty tank :cry:

    Mike
     
  4. TDH

    TDH Funster

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    Thanks for those.

    When you talk about 'resetting', what does that mean?

    And the peg goes where?

    Sorry to be so gormless!
     
  5. TDH

    TDH Funster

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    I've just had a look at some other postings about the dump valve and it seems that they are available with a manual action as well as the automatic. Looking at mine I can't figure out how or wher I would use a peg - how can I distinguish between manual and automatic valves?
     
  6. GJH

    GJH Funster Life Member

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    The manual dump valve is yellow. I've attached a picture from my handbook. It is mounted directly over a hole in the floor so the water just runs out when it is opened.

    I've been trying (unsuccessfully) to find a thread from last year because there is also (on our van) a flexible drain pipe which (if memory serves) is some sort of overflow pipe for the water heater in case it goes wrong. Could that be the extension pipe you mention in the OP?
     

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  7. TDH

    TDH Funster

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    Thanks Graham - mine is yellow so I assume it's the manual version. I can't see that the extension was performing any function - it was kinked and rammed up and over a chassis member, so obviously nothing was coming out of the tank anyway except whatever backed up and into the wardrobe.

    If it's manual, I'm assuming that the reset is irrelevant, and I just need to put the lever in the horizontal position, refill the tank and then get rid of any airlocks in the pipework to the taps. Does that sound about right?
     
  8. GJH

    GJH Funster Life Member

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    I've never known anything come out of the flexible pipe on our van so I think it's just an emergency thing. Wish I could find that old thread but still can't. It was somebody having problems on an Autoquest like ours.

    Yes. Once the cold water tank is full (or full enough) I usually open the cold tap on the sink to prime that and then the hot tap. It coughs and splutters for a while but eventually will fill the hot tank and start to flow properly. Once that happens I turn off the sink tap and then go through the same procedure with the shower and washbasin taps.

    I think some people open all the taps at the same time to speed up the process and/or avoid airlocks.
     
  9. TDH

    TDH Funster

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    Thanks for your help all.

    :thumb:
     
  10. TDH

    TDH Funster

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    Sorry, back again, mystified.

    The dump valve outlet had a pipe attached to it, which disappeared up into the chassis somewhere. I took it off and emptied the hot tank, just as its supposed to happen.

    I refilled the cw tank, put the taps on to prime the system and, lo and behold, all the water in the tank was pumped out of the aforementioned pipe.

    Is there any reason why there should be a pipe delivering fresh water to the outlet of the manual dump valve?

    If I had some hair I'd be tearing it out!
     
  11. alcorn54

    alcorn54 Read Only Funster

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    Ive just had the same problem The dump valve opens at 8 degrees and dumps water in heater unit,so you must heat unit up first to working temperature and a little above to be on safe side . Then push release button in on the valve bottom back .
    If it stays in turn water pump on ,keeps your eyes on it for a few minutes to make sure its stays closed , Bleed your water through to all taps and loo. You must in this weather leave unit switched on to keep it warm. However whilst driving ,switch your water pump off because if the dump valve opens it will continue to pump out all your water if on. When you reach your destination repeat above and you should be ok.:thumb::thumb: A pain I know. Basically if the dump valve is open the water thinks a tap or something similar is asking for water and starts pumping ,it wont stop until pressure is felt ,ie: tap is turned of Alan
     
  12. TDH

    TDH Funster

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    Thanks for that Alan - I saw the title of your earlier post and realised I'm not alone. My problem is a bit different though - the valve is a manual one on mine. Its nt a prob with it draining the water, I just can't figure out why there's a water supply to the outlet of the valve!

    Cheers,

    T
     
  13. GJH

    GJH Funster Life Member

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    I've just been out to our van and taken the two attached photos. The first shows the blue hose from the cold water tank coming from over the rear of the hot tank and attaching to the dump valve, then another blue hose from the dump valve routed round the front of the hot tank.

    The second photo shows the other end of that blue hose as the inlet to the tank and above it the hot water outlet. The red hose is the feed for the taps and the translucent white hose is an overflow which loops upwards and is then routed through the floor of the van.

    The dump valve is mounted on the floor and has no extension hose, so releases the water directly through a hole in the floor underneath it.

    Is it possible that the valve isn't properly closed or a piece of hose has come adrift from a junction? It might be worth filling the cold tank and priming the hot system then change the position of the valve lever to see if it only shuts the valve in a particular position.
     

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  14. TDH

    TDH Funster

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    Thanks Graham. I'll compare when I get home.

    Just had the most ridiculous conversation with the dealer who fitted the heater for the previous owner 18 months ago. The receptionist had never heard of a Tabbert FFB and kept telling me that those terms meant nothing, they wanted to know who the previous owner was and then said they would have to charge me £60 to advise me on how they'd fitted the unit.

    Drives you crackers doesn't it? All I want is for someone to explain to me what they've done and how it works. It's like getting blood from a stone now they've had the £1000 for fitting the new heater.

    Grrrrrrrrrrr!
     
  15. alcorn54

    alcorn54 Read Only Funster

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    Hi Although manual it does the same job,its probably jammed open a little. go to the truma site ,there an e mail for tech help,attach photos and explanation and they will get back to you. Easy way to test is remove pipes from either end join pipes and see if water runs correctly. Heres the technical advice email for truma hope it helps. technical@trumauk.com;
    Alan
     
  16. alcorn54

    alcorn54 Read Only Funster

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    Its probably open ,as its meant to drain your tank when opened,when closed its just a dead end. Alan
     
  17. pappajohn

    pappajohn Funster Life Member

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    havent seen one of these heaters so im only guessing.

    the freshwater feed to the boiler passes through the dump valve when its in normal use....open the valve and the fresh water AND the water in the boiler will divert out the bottom of the van resulting in no water at all in the tank or boiler.
     
  18. pappajohn

    pappajohn Funster Life Member

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    that will probably be an overpressure relief valve incase the boiler stat fails and it just keeps getting hotter and hotter.
    far better to release the pressure in a controlled manner than a bloody big and hot BANG ! :Laughing:
     
  19. TDH

    TDH Funster

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    Thanks John. There's a water supply to the outlet (dump pipe) of the valve!!:cry:
     
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