Guest Tracker Posted October 9, 2009 Share Posted October 9, 2009 It is a very efficient space and water heating system as long as you have diesel and plenty of battery power. However I noticed recently when parked on some gravel that a small amount of water spills out of the hot water drain off via the pressure release valve when the hot water is heating. On enquiring from both Eberspacher and other sources I get back mixed and contradictory views. Obviously when water gets hot it expands and although one might expect the system to absorb such expansionary pressure I am not surprised at some leak off - usually about a mug full. This seems to be a view shared by a couple of Eberspacher agents and caravan service agents who do not seem overly concerned. Eberspacher themselves advise that whilst it is not abnormal I could always replace the present 4 bar pressure relief valve with the latest 3 bar release version - although quite how a lower pressure spill off will help they did not explain? The leak off can be immediately stopped by opening a tap to release the pressure but will start again in a few minutes when pressure builds up again - especially if hot water is being used whilst being heated. Has anybody else experienced this please? Link to comment Share on other sites More sharing options...
libby Posted October 9, 2009 Share Posted October 9, 2009 I would have a guess at you losing more water at a lower bar pressure release. Link to comment Share on other sites More sharing options...
Mike H Posted October 9, 2009 Share Posted October 9, 2009 Hi Rich. Mine is exactly the same. Noticed it whilst away last when parked on hard standing. As you said, pressure relief valve working, and haven't taken any more notice since. Everything is working OK, so will leave alone. Mike. Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 10, 2009 Share Posted October 10, 2009 Thanks Mike - that's my feeling too - but I might just take the valve out and take it apart and clean it when I'm feeling bored and it ain't raining as it appears to be disassembleable (nice word eh!). Link to comment Share on other sites More sharing options...
Mike H Posted October 10, 2009 Share Posted October 10, 2009 Rich. Just, take it apart and clean it, seems to be the easiest option. Mike Link to comment Share on other sites More sharing options...
ALAN G Posted October 11, 2009 Share Posted October 11, 2009 my Autocruise Vista is stored in our garage. After the Eberspacher immersion heater has been switched on for a while a small patch of moisture appears on the garage floor. (Much less than a mugfull though) However, its been doing this for years and hasn't ever affected the supply of hot water. On site, with the immersion on, the pump can be heard repressurising the system from time to time. Its a long time since I drained the system but I seem to remember that the relief valve is also the drain valve. If so you could try operating it to "clear" any rubbish or to reset the spring in the relief valve. Unless its really bothering you I shouldn't worry. Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 11, 2009 Share Posted October 11, 2009 Thanks Alan - I already have opened and shut the drain valve quite a few times with the pump running in the hope that movement might free it up or flush out any crud - but it made no difference. I understand from Eberspacher that the pressure relief valve seats onto rubber and I suppose that it is possible that the rubber has degraded in some way - much as tap washers do? As it is so easy to get at and get out I think that I'll dismantle and check the valve out if only to satisfy my own curiosity and I'll let you know what I find for future reference - but not this week as we are away again! Thanks for your input. Link to comment Share on other sites More sharing options...
colin weston Posted October 11, 2009 Share Posted October 11, 2009 My Autocruise Starburst exhibited the same problem. As it was still under warranty the local Eberspacher agent changed the valve. He said that it wasn't the first valve he had changed on a campervan. Things seemed to improve for a while, but recently I noticed a wet patch below the drain. I deduced that heating water in the system raises the pressure sufficiently to open the relief valve. I, too, have ceased to worry about it. Personally, I don't think it is a dirt problem as I always drain my system at the end of every trip. Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 19, 2009 Share Posted October 19, 2009 I took the non return / drain down valve out today - easily accessible and very simple to get out - on my van at least. It's equally simple to dismantle with no nasty surprises and it was indeed quite gungey around the brass seating onto which the spring loaded rubber pressure valve sits. The rubber valve pad was also a bit messy and the combination might well have caused a poor seal, but both parts cleaned up very easily and reassembled just as easily. On heating the water there was a very small dribble just before the boiler cut out at which time the water was bloody HOT - less than a dessert spoon full dribbled out so it looks as if cleaning does help. Whether it avoids the need for a new valve only time will tell but as all the internal components seem to be in good condition I am optimistic. Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 20, 2009 Share Posted October 20, 2009 It seems that Eberspacher will only supply to one of their own agents and the two that I spoke to had no idea what a pressure reduction valve/ drain down valve was for so rather than faff about with them I began to look elsewhere. This little chappie seems to fit the bill very well so I think that I will order one and keep it in the van just in case - for less than a tenner it seems a worthwhile bit of insurance to carry. http://www.plumbworld.co.uk/12-3-bar-mf-pressure-relief-231-55 Link to comment Share on other sites More sharing options...
Harvey Posted December 13, 2009 Share Posted December 13, 2009 I found this thread quite interesting but I have a question not answered here, but as you guys seem to know what you are talking about ......... I have an Eberspacher 'Compact' Combitronic in my Autocruise Starblazer. This is the one that is completely contained in a 'box' under the 'van. I want to drain down the water. There is a red knob on the front of the 'box' which I was told was a pressure relief valve but is presumably also the drain valve. ( nothing about this in the instruction book, or in the Autocruise manual ). The red knob on mine has actually come off because the retaining grip-clip rusted, but it appears that turning it would cause it to 'cam' outwards and so pull the valve spindle outwards. Is this how one would drain the water out? If so, I can just pull the spindle with a pair of grips to open it ...... but then where does the water drain from / to? as the whole unit is inside it's boxed covers except for the valve spindle poking out! I didn't drain it last year: just kept it on the 'frost' setting but that is a rather costly exercise. Just to clarify for those who have a similar, but not exact same system. the 'compact' does not have a hot water tank *inside* the 'van. I'd appreciate any comment / advice. thanks, Harvey p.s. I'll refit the Red Knob when I get hold of a new clip. Link to comment Share on other sites More sharing options...
Guest Tracker Posted December 13, 2009 Share Posted December 13, 2009 I don't know about your system Harvey but one assumes that if there is a drain knob then it must drain out somewhere beneath the van? Is there some confusion I wonder between the Eberspacher sealed heat exchanger system and the van's hot water tank? I don't drain the Eberspacher heat exchanger itself as it has anti freeze in it - which I recently topped up with some more anti freeze - just in case! I only drain the 'domestic' hot water tank and if you don't have a water tank to drain why drain the system at all - as long as it has anti freeze? Link to comment Share on other sites More sharing options...
Harvey Posted December 13, 2009 Share Posted December 13, 2009 Tracker - 2009-12-13 12:56 PM I don't know about your system Harvey but one assumes that if there is a drain knob then it must drain out somewhere beneath the van? Is there some confusion I wonder between the Eberspacher sealed heat exchanger system and the van's hot water tank? I don't drain the Eberspacher heat exchanger itself as it has anti freeze in it - which I recently topped up with some more anti freeze - just in case! I only drain the 'domestic' hot water tank and if you don't have a water tank to drain why drain the system at all - as long as it has anti freeze? Thanks Tracker; but;----- yes I *do* have a hot water tank, which is what I want to drain as well as any water in the Eber unit itself. It is underneath the 'van in the 'box' with all the other Combitronic stuff. No I'm not trying to drain the antifreezed coolant. OK, so the Eber water heater systems which have an inside water tank: where is the drain valve for that, so that the 'heated' water is drained from the Eber unit? I assume that does happen otherwise residual water in the heater unit ( not the hot storage tank ) could freeze. Does it work as my 'red knob' would: ie. turn it, about a quarter turn, I assume, which cams out the valve spindle? This 'compact' Combitronic is a bit rare and only fitted to the XL versions of the Starblazer as far as I can ascertain. ( although may be in other model Autocruises ) I don't think it is available now. Anyone else with an 'XL' Starblazer? Ta, Harvey Link to comment Share on other sites More sharing options...
Guest Tracker Posted December 13, 2009 Share Posted December 13, 2009 Sorry - my mistook! There does not seem to be a drain tap for the coolant on my Combitronic either (Starburst 2006) so I suppose one just undoes one of the black coolant hoses at the lowest point and drain it down if one needs to, but unless there were a fault or a leak there should be no need as long as the system has enough anti freeze? Yes - the red knob just rides up on a cam to drain down the hot water tank. I am a little confused in that you mention draining the system with an indoor water tank? The heat exchanger which conducts the heat from the anti freezed water - which serves both as coolant and as heat conductant - is inside the insulated hot water tank and as far as I know there is not a third source of water in the system? As far as I know there are only two elements of the system that have water in them? One is the domestic hot water tank itself which we have identified as being drainable via the red knob and the other is the system's heat exchanger with anti freeze in it which has the black rubber hoses and does not need draining unless it has no anti freeze? Or have I misunderstood where you are coming from? Link to comment Share on other sites More sharing options...
Harvey Posted December 13, 2009 Share Posted December 13, 2009 Tracker, yes you did misunderstand me but that was my fault. I do know how this system works but I must have had brain fade, talking about water left in the heater: of course there will be none. It's having the water tank all enclosed under the 'van, in with the Hydronic unit etc. it got me wrong thinking and you have got me right thinking again :-D I'll find out where the water comes out when I open the valve tomorrow :-D Thanks, Harvey Link to comment Share on other sites More sharing options...
Harvey Posted October 8, 2010 Share Posted October 8, 2010 Tracker - 2009-10-20 12:32 PM It seems that Eberspacher will only supply to one of their own agents and the two that I spoke to had no idea what a pressure reduction valve/ drain down valve was for so rather than faff about with them I began to look elsewhere. This little chappie seems to fit the bill very well so I think that I will order one and keep it in the van just in case - for less than a tenner it seems a worthwhile bit of insurance to carry. http://www.plumbworld.co.uk/12-3-bar-mf-pressure-relief-231-55 Re-visiting this thread because now, my relief valve is leaking quite a lot: I haven't measured the water loss but it is more than a small drip. Did you ever buy or fit one of those that you linked to tracker? or was your cleaning job found to be a good long term fix? My valve is rather inaccessible so need to consider options. I don't want to do the job twice ........ Harvey Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 8, 2010 Share Posted October 8, 2010 Having already removed, cleaned and refitted the original valve I went and bought the new valve as linked to and took it with us on about half a dozen trips in case I needed to use it. Having that failsafe seemed to prevent Soddes Law from applying and apart from a few drips it gave no trouble. However seeing as I already had the bit and in a moment of boredom I replaced it earlier this year and it now works fine with no dribbles. Job done - until summat else goes wrong! Link to comment Share on other sites More sharing options...
Rayjsj Posted October 8, 2010 Share Posted October 8, 2010 Tracker, Just read through this thread, very interesting, The new(for me) world of Combitronic heaters. I have yet to investigate mine properly, I have read the manual, but not sure which model i have (2005 Starlet II) ? from the manual it looks like I have to do nothing for the winter except press the * button on the panel, keep it on electric hookup and IT does the (slightly expensive) business of looking after the interior of the van including hot water system and itself. Is it correct ? Using the system for an overnight stay and a warm journey home was a very pleasant change, from freezing in a draughty Talbot cab with it's puny heater. Ray Link to comment Share on other sites More sharing options...
Harvey Posted October 8, 2010 Share Posted October 8, 2010 Tracker - 2010-10-08 10:30 AM However seeing as I already had the bit and in a moment of boredom I replaced it earlier this year and it now works fine with no dribbles. Job done - until summat else goes wrong! Thanks Tracker, I'll take mine out I think, during the winter, have a look at it, then fit a new one :-D Harvey Link to comment Share on other sites More sharing options...
Harvey Posted December 7, 2010 Share Posted December 7, 2010 My leak turned out to be not the drain valve but the immersion heater sealing ring being split. Harvey Link to comment Share on other sites More sharing options...
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