andy mccord Posted May 30, 2013 Share Posted May 30, 2013 My boiler is spitting a short burst of water out of the drain down pipe when the heater is on, which inturn is causing my pump to constantly keep water pressure in the system, any ideas why folks? Andy Link to comment Share on other sites More sharing options...
tonyishuk Posted May 30, 2013 Share Posted May 30, 2013 Best guess, the internal pressure from your pump is little too high, and / or the pressure release valve on the Truma is a shade low. The heating of the water is enough to raise the pressure for the valve to release. How you can tell the difference I do not know. Never seen a discussion on testing the water pressure in a m/home or Caravan. Rgds Link to comment Share on other sites More sharing options...
andy mccord Posted May 30, 2013 Author Share Posted May 30, 2013 Hi Tony thanks for the reply ,I have had this happen before on a previous van but it resolved itself somehow so I never investigated further, I agree pressure is wrong somewhere, but were I don't know, it really spits it out at a fair speed, but As I,ve stated the pump keeps priming every 10 mins but I'm sure I don't have a leak as there's no spluttering from the taps Regards andy Link to comment Share on other sites More sharing options...
flicka Posted May 30, 2013 Share Posted May 30, 2013 Hi Andy Have you checked your Truma's frost / drain tap is fully closed ? There maybe a bit of dirt / scale trapped, if so fully open as if to drain, then close. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 31, 2013 Share Posted May 31, 2013 Andy The 'drain down' valve normally fitted to a Truma "Combi" is the type shown here http://tinyurl.com/ld3ru6s (the asking-price seems very high!!!) Unlike the electrically-operated drain-valve normally fitted to the earlier Truma C-Series ranges, this valve is non-electrical (though a 12V heater can be fitted to it). Besides providing frost protection, the valve protects against excess pressure in the water system. As will be seen from the advert, the pressure will need to exceed 2.8bar for the valve to operate. I don't know what happens should pressure in the system exceed 2.8bar - whether the drain-valve is designed to release just sufficient water to lower the pressure (as appears to be happening in your case) or designed to open fully as it would if protecting against frost. I note that a diaphragm water pump (which you've obviously got) will usually have a shut-off pressure of around 2.0bar, so (as tonyishuk advises), your pump may be shutting off above that pressure and the water-heating process pushes the system pressure above the drain-valve's 2.8bar threshold, or the drain-valve is opening below its 2.8bar design-setting. I suggest you contact Truma(UK) about this Tel: 01283 586020 Email: technical@trumauk.com Link to comment Share on other sites More sharing options...
Brian Kirby Posted May 31, 2013 Share Posted May 31, 2013 I agree, contact Truma. The further possibility that occurs to me is that the thermostat has failed, and the water in the heater is actually boiling. That would obviously raise the pressure on the whole system, and is presumably why the drain valve is designed to act as a safety valve. Should the valve fail to operate as intended the result could be quite nasty, so I think talk to Truma sooner rather than later. Link to comment Share on other sites More sharing options...
ips Posted May 31, 2013 Share Posted May 31, 2013 Agree with Brian. Ours has two heat settings have you tried it on the lower setting (if you have one) see what it does then. Link to comment Share on other sites More sharing options...
andy mccord Posted May 31, 2013 Author Share Posted May 31, 2013 Gents Many thanks for the replies, currently in Stirling at the end of a 2 week tour of Scotland , just sat outside with the boiler on and it has spat out 2 short bursts whilst heating up to 60c on full 1800w, there is certainly pressure behind it, almost like a short sneeze from the outlet Many thanks again I will contact Truma Andy Link to comment Share on other sites More sharing options...
Brian Kirby Posted May 31, 2013 Share Posted May 31, 2013 Does it do the same when heating water on gas, Andy? If so, I suspect the thermostat idea is a non-runner (two different stats involved, I think). If it is only when on mains, it could as easily be that a wire has come loose on the terperature sensor on the water jacket. But, someone has to decide which/what, so I'd still be inclined to talk to Truma technical first. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 1, 2013 Share Posted June 1, 2013 Andy I believe you've owned your Adria since the end of 2011. You've not said whether the 'spitting' behaviour has always been present, but I'd guess it's only begun recently. I would have thought you'd notice if the heater were not shutting down when the water reached its 60°C design maximum as the temperature would be serously hotter than you'd been used to. Similarly, if the water-pump were pressurising the system unusually highly, you'd notice this at the taps. If we assume both the heater and water-pump are acting normally, that leaves the drain-valve as the prime suspect. Link to comment Share on other sites More sharing options...
andy mccord Posted June 3, 2013 Author Share Posted June 3, 2013 Hi Brian, Not tried the van on gas only yet... Derek, this problem has only just started, im also pretty sure that the spitting action acutally occurs before the heater on light indicates it has even reached 60c,but I will double check this soon to confirm. the water it spits out appears not to be steaming so its not to bad :-S but the one thing that appears to be linked is the pump keeps repressurising more than it ever did before. Regards Andy Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 4, 2013 Share Posted June 4, 2013 andy mccord - 2013-06-03 12:19 PM ...the one thing that appears to be linked is the pump keeps repressurising more than it ever did before. Regards Andy The drain-valve will be located in the high-pressure side of your motorhome's water system (ie. 'downstream' of the water-pump). With a pressure-sensitive diaphragm pump, if water is being lost through the drain-valve, the pressure in the water system will be lowered and the pump will run to compensate for that drop in pressure. As a generalisation, unless air enters on the low-pressure side of the water system (ie. there is a leak somewhere 'upstream' of the water-pump) there's no reason to think that spluttering from the taps will result. Having reread your postings I'm not 100% sure if your pump is now repressurising every 10 minutes only when the heater is running and the drain-valve is spitting, or whether the pump keeps repressurising even when the heater is not operating. Certainly, when the spitting occurs, one should expect the pump to operate shortly afterwards but, either way, I still think the problem lies with the drain-valve. Have you tried manually opening and closing the drain-valve a few times (when the water system is pressurised) to check if that does any good? This ploy was suggested earlier by flicka on the basis that the valve's internal seal may have some dirt in it and not be seating properly. I don't think these valve's are designed to be dismantled/serviced (Truma(UK) would know) so, if the valve's genuinely faulty, a replacement would probably be needed. Assuming that your Adria Coral waas brand-new when you obtained it in late 2011, its Truma equipment should still be within Truma's 24-month warranty period. Link to comment Share on other sites More sharing options...
andy mccord Posted June 4, 2013 Author Share Posted June 4, 2013 Good point Derek, going to try whether the pump cycles only when the heating is on or not later this week, I will also try Flickas recommendation ref flicking drain valve on and off a few times and I will report back, It makes me nervous the pump cycling as our very first trip involved the same pump cycling noise along with spluttering taps, looked under the hatch and the inline filter nefore the pump had split and water was spewing out 8-) Regards Andy Link to comment Share on other sites More sharing options...
andy mccord Posted June 7, 2013 Author Share Posted June 7, 2013 Ok I've contacted Truma who were not overly helpful , they are telling me that the pump pressure is to high. I have operated the drain valve on and off but to no avail, the outlet now drips permanently when the boiler is on. To turn the pressure down on the pump means I will have to remove it to get to the screw....great Andy Link to comment Share on other sites More sharing options...
andy mccord Posted June 7, 2013 Author Share Posted June 7, 2013 Just to add, The drips from the outlet are cold :-( In your opinion if I turn the screw on the pump down will it solve it and how much should I turn the screw? Regards Andy Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 7, 2013 Share Posted June 7, 2013 Andy, just to be clear, are you saying the drips are cold with the water heating on, or that they continue all the time the water heater is filled, hot or cold? From what you have said, this started with water being expelled from the drain valve discharge pipe. It had not been noted before. It seems a little unlikely to me that the pump will have spontaneously gained pressure over time (not impossible if the screw to which you refer was not locked in position, but nevertheless not likely, IMO). When the heater is first filled the water is cold. As the water is heated it will expand, so increasing system pressure. There is a non-return valve on the cold feed to the heater to prevent warmed water being expelled back to the cold water tank so, once the pressure rises sufficiently some water will be likely to be expelled via a pressure relief valve. The exception would be if the system has a surge damper or similar installed, which might be expected to absorb the increased pressure without triggering expulsion. You have operated the drain-valve to see if the dripping stops, but this seems instead to have exacerbated it. It seems to me that this points to the drain-valve as probably being the culprit. Can you remove this to examine it more easily? It may simply need back-flushing to clear any particles of limescale or grit that might be obstructing normal closure, or it may be that the seal has split (however, depending on cost, it may just be easier to replace it with a new one, rather than spend time fiddling with the present one). This should be the simplest and most cost-effective step. If it is the pump pressure that is at fault, the problem will persist whatever you do with the drain-valve, but if it is the drain-valve that has become faulty and you reduce pump pressure, the reduced pressure will probably mask the drain valve fault initially, but the underlying fault with the valve will remain, and it will be liable to start dripping again as the fault worsens. So, on balance, I think start with the drain-valve and only adjust the pump once it is clear the fault does not lie in the valve. Link to comment Share on other sites More sharing options...
andy mccord Posted June 7, 2013 Author Share Posted June 7, 2013 Hi Brian the dripping has stopped, the water was cold even with the boiler on full, I have just put the boiler back on then turned the pump off and run some hot off to see what would happen, it still spits out a burst even before 60c is reached, I am unsure whether I can get into the valve or not? I really would hope that the valve is the issue, but I need to convince Truma that it is faulty and I really want to avoid taking my van into the dealership Andy Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 7, 2013 Share Posted June 7, 2013 Afraid I'm a bit lost on this Andy. I understand that the drips are cold, presumably with the water heater at full temperature? (I know you said "on full", but that could mean at its maximum setting while still not fully hot, or at its maximum temperature but no longer actually heating the water). My immediate reaction is that the seepage is relatively slow, so the water is merely cooling as it drips. However, "put the boiler back on, then turned the pump off, and run some hot water off" puzzles me. How did you run off hot water with the pump off? Then "it still spits out a burst even before 60c is reached". Is this while running off the water, just while it is heating up, or when you close the tap after runing off the hot water? I don't think you will convince Truma over the 'phone that the valve is faulty and, even if you do, isn't the Truma kit now out of warranty? Derek referred to your van being a 2011. If correct, isn't the Truma warranty for one year? If you are hoping this can be resolved under warranty, I think you'd need to take the van to the dealership for them to investigate and decide where the fault is, before Truma (or anyone else) would concede on a (possibly late) warranty claim. In other words, I would think you'd need the dealer to support a warranty claim. That apart, the fault is the dealer's liability under Consumer legislation, whether or not the warranty has expired, although his liability to replace or repair diminishes with the passage of time. But, if he is not involved, he cannot be expected to act. I suspect that the location of the valve is the main problem, meaning that it will be time consuming to replace or repair. I doubt the valve is that expensive relative to the cost of labour to replace it. If the dealership is a long way from where you live, and the cost of a return trip (possibly two) is greater than the cost of a new valve, wouldn't your cheapest solution be to buy a new valve and DIY? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 8, 2013 Share Posted June 8, 2013 The duration of a Truma warranty is normally 24 months and I'd expect that to apply to a safety/drain valve as well as to major appliances. The safety/drain valve will be positioned in the motorhome's cold-water pipework after the water-pump and before the pipework divides into feeds to hot- and cold-water outlets. As a pressure-sensitive diaphragm water-pump is involved, that pump will act as a non-return valve preventing water from siphoning back into the fresh-water tank. If the safety/drain valve expells water due to 'over pressure' being detected by the valve, it should be expected that this water will be cold irrespective of whether or not water is being heated. For hot water to travel back down the pipework from the heater to the valve would require a good deal of water to be expelled, not just a 'spit' or two. I don't know what make/model of water-pump Adria fits, but the most commonly used is probably SHURflo's "Trail King". These are available with output pressures from 20psi to 40psi, but it's usual for motorhome manufacturers to choose the 7litres/minute 30psi model. This file http://www.truma.com/downloadcenter/frostcontrol_installation_instruction_de_gb_fr_it_nl_dk_es.pdf describes the current Truma Frost Control valve. This advice is given on Page 10: "Overpressure safety valve At an overpressure of up to max. 4.5 bar (e.g. created when heating up the boiler), the FrostControl opens automatically and releases the overpressure to the outside intermittently via a draining connection." This tallies with what's happening with Andy's Adria, but 30psi = 2.07bar and it's a awful long way from 2.07bar to 4.5bar. Fiddling about with a pump's adjustment screw is normally done to address rapid cycling by the pump and (although it's worth a try) I can't see it curing this problem. Asking prices for these latest Frost Control safety/drain valves seem to be from £50-£100 and (as I said earlier) I believe they are not repairable. There seem to be 3 logical possibilities... 1: The heater is causing a massive pressure increase in the water system (unlikely). 2. The water-pump is massively over-pressurising the water system (unlikely). 3. The safety/drain valve is opening well below 4.5bar (my favourite). Link to comment Share on other sites More sharing options...
ips Posted June 8, 2013 Share Posted June 8, 2013 Derek one assumes that a qualified engineer could carry out a pressure test on the system to confirm ? Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 8, 2013 Share Posted June 8, 2013 Also 4.5 bar is approx 65psi, which appears to be nearly double the maximum delivery pressure for the usually provided water pumps. So, it would appear that the frost protection valve is opening, as Derek suggests, probably well below its design pressure. It is odd that it has only recently started doing this, however, as I assume the release pressure is determined by a spring that holds the valve closed. A sudden weakening of this, also, seems to me somewhat unlikely. The odd spring can snap under pressure, but it is unusual. Dripping from the valve has been mentioned, suggesting that it is not closing as it should. I have no idea how this valve is arranged internally, but I do just wonder if debris might be obstructing the proper closing of the valve, such that it is prone to opening "early". I therefore think it might be worth a little DIY investigation to see if the valve can be removed, to try to check for anything lodged inside it. I assume that if the van is taken to the dealer, and they investigate and find debris, Truma would be likely to reject a warranty claim, as the fault would (probably, depending on what was found) not be of their making. It might be laid at Adria's door, if it were clearly something like a pipe trimming, but would be as likely to be laid at the door of the owner, who would be presumed to have dropped something into the tank, possibly while initially flushing it. The risk, in either event, is the potential labour charge. If the valve can be removed and examined, and no obstruction can be found, it can then be put back into place and the matter taken up via the dealer, on the reasonable assumption that the owner has not inadvertantly caused the problem. But, obviously, I'm guessing! Link to comment Share on other sites More sharing options...
andy mccord Posted June 8, 2013 Author Share Posted June 8, 2013 Once again Brian/Derek many thanks for your replies, after filling the boiler 4 times then releasing the water I have finally managed to get the boiler to heat the water up to full temp, switch off, and no spitting out of the outlet. I am hoping that it was debris in the valve, but I am not confident if Im honest. The valve is really easy to get out so I may remove it if it starts again, there appears to be a clip on one end of it so access may be possible. Brian, what I was trying to tell you was that once I had got the boiler up to full temp, I turned of the pump and opened a hot tap for a few seconds to possibly release a bit of water pressure in the boiler to see if it still spat out, which it did. Hope this makes sense. Regards Andy Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 8, 2013 Share Posted June 8, 2013 Gotcha! :-) Not sure I'd do any more than remove it and look at it, though. Once removed, that clip may release bits that would be very difficult to re-fit! If it is a duff valve, you don't want Truma saying they can see you've been tampering with it! Looking at Derek's .pdf, it seems that the valve itself is probably contained within that T piece at the end, which you should be able to squint through, so may be able to see if there is something caught inside. Possibly a piece/pieces of plastic trimming from the pipes, or even from the fresh water tank. If debris had caught under a soft washer/seal of some sort it may have dimpled it, causing that dripping. If that is all, it should gradually regain its original shape once the debris is cleared, and seal properly again after a while. Looking at the connecting spigots, I'd guess getting the pipes freed might be a bit of a game! Let's just hope it has now flushed out whatever was causing the problem, and will settle down to be trouble free. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 9, 2013 Share Posted June 9, 2013 ips - 2013-06-08 8:28 AM Derek one assumes that a qualified engineer could carry out a pressure test on the system to confirm ? I don't think a "qualified engineer" would be needed to test the pressure at which a Truma safety/drain valve opens. It would just be a matter of sealing off the valve's inlet, pressurising on the outlet side and noting the pressure at which the valve opens. A simple enough DIY task really. Similarly, it ought to be relatively straightforward to cobble together something to permit the pressure in the water system as a whole to be checked. I don't know if Truma carries out this type of pressure-testing. I do remember them leak-testing the water vessel of my Herald's 'combi' heater by submerging the vessel in a sink full of water and then pumping air in (the traditional tyre-puncture test). The air hose detached from the water vessel causing the hapless technician to be soaked by the water thrown out of the sink - how we all laughed! In Andy's case, if the Truma heater were heating the water well beyond its maximum design-temperature (which could cause significant over-pressure) it should be apparent that this was happening eithe by the water becoming unusually hot or the heater operating for an unusually long period. Most people will have a fair idea how long their Truma heater takes to heat water to a chosen temperature and are likely to become aware if it is taking a lot longer than normal and/or the heater is failing to shut down. Realistically, the only ways a pressure-sensitive water-pump is likely to over-pressure a water system is if a 'wrong', too powerful pump has been fitted or the pump fails to shut off. There's no reason to think Andy's pump is 'wrong' and it clearly does shut itself off. Tricky things assumptions - I refer you to the lyrics of "The Assumption Song" by the Arrogant Worms. Link to comment Share on other sites More sharing options...
andy mccord Posted July 26, 2013 Author Share Posted July 26, 2013 Well the problem has reared its head again, I have contacted campbells, they have supplied me with the red one way valve which comes off the boiler, Ive fitted it this morning, and it spat out yet again, I think Im going to go for what you guys are suggesting and purchase a new frost valve, I dont believe the pump is over pressurising, ive never touched it and for the first 16 months all has been well ( Shurflo Trail king 7). The boiler is behaving normally IMO, it takes approx 20 mins on full power to get to 60c which is pretty much what its always taken in time and the water is not overly hot, just right really so here goes £70 gamble time :-| Regards Andy Link to comment Share on other sites More sharing options...
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