hmpoliveira Posted January 30, 2016 Share Posted January 30, 2016 Hi there I've got a Hymer Motorhome from 2012 (new for myself) with a lack of hot water.... After the Truma system is properly heated we have maybe 45 seconds of hot water which decreases until it becomes cold (either in the shower or kitchen). There's no error light popping out of the Truma panel.... Heating is working fine and water is flowing also with no issues. Any tips? Thank you all in advance. Link to comment Share on other sites More sharing options...
bolero boy Posted January 30, 2016 Share Posted January 30, 2016 could be air in the hot water tank, although ypu say the flow is strong.....but quickly cool.... so, assuming the tank is full of water, then their really is only a tiny bit pf water that is hot..... so, does the tank feel hot whenthe heating phase is complete? do you het the same result when heating water using gas...? Link to comment Share on other sites More sharing options...
Brian Kirby Posted January 30, 2016 Share Posted January 30, 2016 Not sure if I'm correctly understanding what you mean, but these are storage heaters, not the type that heat water as it is demanded. They hold about 12 litres of water, which they heat to either 40C of 60C. When the water reaches the pre-set temperature, the heater switches off, and does not switch on again until the water temperature has fallen by a quite substantial margin. If you want hot water it is better, IMO, to select 60C and then begin drawing hot water as soon as possible after the yellow LED extinguishes, indicating that the set temperature has been reached. You should then have the full 12 litres of water at 60C, to which most would wish to add cold thus eking out the available supply. If you leave the heater on, but don't start using the hot water as soon as the heating phase ends, it is possible you'll get water that is little better than luke-warm (i.e just before the heater begins re-heating). Also, if you run the hot continually for 45 seconds (I haven't tried timing this) I think it likely you may have pumped pretty well all your 12 litres out of the heater. If you also commenced drawing the hot some time after the heater finished heating, the inevitable loss of heat over time will increase the probability of it beginning to run cool. Link to comment Share on other sites More sharing options...
Robbo Posted January 30, 2016 Share Posted January 30, 2016 I'd just like to add to Brian's comments. Most pumps deliver between 7 to 10 litres per minute so the hot water in the 12 litre capacity boiler isn't going to last very long if continuously drained. As Brian suggests, best to use the 60C setting and mix with cold water to make the shower time last longer. It is assumed that the OP is using gas to heat the water. If an alternative electric facility is available and used, then I assume this would heat to a lower temperature of say 40C. This is pure conjecture as I am not familiar with the heating of water via 240volt. PS. As an afterthought, just check when running the hot water that there is no water escaping from underneath the van. My Hymer van had a stop cock for both hot and cold water systems for draining down for layup in sub zero temperatures. Link to comment Share on other sites More sharing options...
Tracker Posted January 30, 2016 Share Posted January 30, 2016 This might just be down to showering technique? With limited hot water it is best to get the tank of water as hot as you can then use the wet down, soap up and rinse off method of showering with, for us, limited flow to wet down, water flow off whilst you soap up and wash yourselves and on again either full flow and heat if you need to or a bit less if you can for rinsing off in which case better to wait 15 mins between showers to allow a bit more heat to build up. We then use flannels to get the excess water off before using a towel to dry off. That way the towels don't get so wet. Using this method we can both get a shower and a hair wash out of one tankful of hot water but to be fair it is touch and go if the first one in is a bit too greedy - after all 12 litres - less than 3 gallons in old money ain't a lot and it does take a while to reheat! Link to comment Share on other sites More sharing options...
Basil Posted January 30, 2016 Share Posted January 30, 2016 Have to say this Truma 'thing' is the one area that we are unhappy with in our new van, what a load of rubbish! Having had a Carver Cascade GE and separate Carver blown air in our previous motorhome for 17 years, faultless and completely effective, this Combi 4E is pretty well useless by comparison. It neither heats the water or interior very well and used without gas on mains only is about as much use as a chocolate teapot and it is tempremental to boot. From my point of view it is yet another overhyped piece of German c**p! OP Don't expect too much from your Truma as it seems that our friends who have the same also find them rubbish and most use alternative methods of heating and hot water (free standing fan heaters and don't use on board facilities). Bas Link to comment Share on other sites More sharing options...
ken the kontiki Posted January 30, 2016 Share Posted January 30, 2016 Having worked for a leading shower manufacturer for many years, this bit of info might be useful: For a shower temp of c.43 degC and with hot water at 60 degc and cold at 10 degC, the flow is made up of 2/3 hot and 1/3 cold. So for a 6lt/min shower, that would be 4lt of hot and 2lt of cold. For a 12lt Truma boiler, you can quickly see that you'll be out of hot water in around 3 minutes. These are only approximate figures but give some idea as to how far stored hot water will go. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted January 31, 2016 Share Posted January 31, 2016 Tracker - 2016-01-30 7:25 PM This might just be down to showering technique? With limited hot water it is best to get the tank of water as hot as you can then use the wet down, soap up and rinse off method of showering with, for us, limited flow to wet down, water flow off whilst you soap up and wash yourselves and on again either full flow and heat if you need to or a bit less if you can for rinsing off in which case better to wait 15 mins between showers to allow a bit more heat to build up. We then use flannels to get the excess water off before using a towel to dry off. That way the towels don't get so wet. Using this method we can both get a shower and a hair wash out of one tankful of hot water but to be fair it is touch and go if the first one in is a bit too greedy - after all 12 litres - less than 3 gallons in old money ain't a lot and it does take a while to reheat! That sums up the situation perfectly. A Truma “Combi” combination air/water heater would have been fitted to a 2012 Hymer motorhome. The Combi’s predecessor was the “Trumatic-C” range with a water capacity of 12 litres and motorcaravanners unfamiliar with those heaters used to make exactly the same complaint about limited hot water. The water-capacity of a “Combi” is 10 litres, which potentially makes matters worse. These two 2012 links may be of interest: http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/New-Truma-Combi-4E-Problems/29335/ http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Eco-Camel-Shower/29382/ Truma’s FAQ advice about Combi water-heating is as follows: "How long does it take for water to heat up in the Combi? 1: If only water is being heated up (during summer operation) a temperature of 60 degrees is reached after around 20 minutes. 2: If the living area is being heated and the boiler is being operated (during winter operation) a water temperature of 60 degrees is reached after around 80 minutes. 3: It is possible to heat up the water in electrical operation alone (i.e. entirely without gas). The heating time in electrical operation is around 45 minutes.” Showering in a motorhome equipped with a small-capacity water-heater using the same technique as one might employ with a domestic, hotel or campsite shower invites a rude (and cold) awakening. Besides adopting the type of method Tracker employs, technical modifications may help further. The shower equipment fitted to most modern motorhomes tends to be high on bling and low on water conservation. My Rapido’s shower has a ‘mixer’ shower-control. This makes setting the water-flow from the shower-head to a comfortable temperature difficult and it’s easy to accidentally knock the control out of adjustment. Fiddling about with the mixer-control inevitably wastes hot water. My motorhome also has an “Ecocamel” shower-head (fitted as standard by Rapido). This is fine in principle as it delivers a mix of ‘aerated’ water intended to provide a superior showering experience to water alone being delivered. Experience-wise It works - sort of - but it’s still a water-wasteful free-flow system and, if you want to shut off the water during showering, you still need to do it at the mixer-control. Ecocamel offers a shut-off valve to address this https://www.ecocamel.com/shut-off-valve/product?product_id=814 and it would be worth considering obtaining one of these valves if anyone finds the idea of an Ecocamel shower-head attractive. However, it's probably better to choose a shower-head with a lower flow-rate and an integrated trigger or switch as was commonplace in UK-biuilt motorhomes in the 1990s. These as readily available, marketed for leisure-vehicles or for ’shattaf’ applications. Examples here: http://www.nature4energy.co.uk/Bidet-range.html Link to comment Share on other sites More sharing options...
bolero boy Posted January 31, 2016 Share Posted January 31, 2016 we must be doing something totally wrong..... our combi6E (mainly used in electric only if on sites) gives a full tank of hot water in around 20 mins (despite the truma 'FAQ' above. this allows OH and i to shower successively in the van. i use the Tracker technique, a quick in and out..... by being brief, this allows OH to (by comparison) luxuriate in the shower and generally has at least twice as long as me enjoying plenty (in van shower terms) of hot water.... ensure water is set to 60 deg and use cold to eke out the supply. we also have an Ecocamel shower head, seems to work ok for us..... either 2nd person showers immediately after first, prior to remaining hot water temp being dragged down by refill with cold, or wait until it has reheated.... yes, 1800w of heating can be a bit limp on the 'older' combis, but the new CP plus panel gives the option to 'force' the fan onto a 'high' setting (not possible on our previous model) which makes 1800w 'seem' to go a lot further..... edit.... another quick tip.....i turn on the washroom hot tap for a few seconds prior to shower, to allow hot water to reach the washroom from the combi....so no waiting for hot when in the shower. also, we know roughly where the mixer tap has to be set prior to shower, again helping to negate the faffing about than can frustrate and waste water. all simple stuff that helps usnenjoy our van's shower rather than curse it.... Link to comment Share on other sites More sharing options...
Rayjsj Posted January 31, 2016 Share Posted January 31, 2016 Basil - 2016-01-30 9:08 PM Have to say this Truma 'thing' is the one area that we are unhappy with in our new van, what a load of rubbish! Having had a Carver Cascade GE and separate Carver blown air in our previous motorhome for 17 years, faultless and completely effective, this Combi 4E is pretty well useless by comparison. It neither heats the water or interior very well and used without gas on mains only is about as much use as a chocolate teapot and it is tempremental to boot. From my point of view it is yet another overhyped piece of German c**p! OP Don't expect too much from your Truma as it seems that our friends who have the same also find them rubbish and most use alternative methods of heating and hot water (free standing fan heaters and don't use on board facilities). Bas I agree a100% with you Basil, I think the Truma CombI is like the emperors new clothes, everyone saying how good it is when actually it's very poor. The best system we have had was a Diesel fired, Eberspacher, never let us down, only thing was you needed a very good battery. As you say the Carver products were more reliable than Truma. They may be more modern, with phone apps. To turn them on remotely, but a more reliable heat/hot water source......No. And the electric only option seems more of an afterthought, I also carry a convector heater, because of unreliability in the past. Link to comment Share on other sites More sharing options...
bolero boy Posted January 31, 2016 Share Posted January 31, 2016 im sure there is a degree of 'user understanding' that helps make the combi friendly rether than a pain..... one unit cant/wont heat the room and a tank of hot water if youre only giving it 1800w to play with..... of you only need hot water......1800w will heat to 60 deg in 20 mins or so.....it doesnt matter which alternative system is recommended, the user wont get his water much hotter or quicker than this.... now, heating is a different matter.....combi 4E and 6E both only have max 1800w on electric setting. this is a struggle in a large van....cant really be anything else......however, the new CP plus with 'high' fan setting is a real improvement.....older models can be upgraded with PCB change..... for most situations, mixed mode of gas/ehu will quickly heat the van and then throttle back the gas leaving the 1800w of leccy maintaining heat..... its not a 'bad' unit, per se, just needs a bit of local knowledge to maximise its potential...... expecting too much and relying solely on leccy to heat a cold van will only lead to frustration.... Link to comment Share on other sites More sharing options...
Rayjsj Posted January 31, 2016 Share Posted January 31, 2016 BB, I dont think it is too much to expect a unit, designed to provide warmth and hot water .........reliably, to do just that, without having to make allowances for it's deficiencies. My Eberspacher heater/water boiler had very complicated instructions to make it work effectively, but managed to provide all that was required of it through the learning phase. Something the Combi 4E, did not do. Shame that they Truma have virtually cornered the market, IMO they don't deserve it. My 15 pound convector heater is more effecient at heating our van, and that is only 1800watt as well. Link to comment Share on other sites More sharing options...
bolero boy Posted January 31, 2016 Share Posted January 31, 2016 a cheap fan heater will have a user controlled fan speed....this is an issue for the older combis, they dont have one....the new ones, with the fan speed control work very well.... most who require heating a cold van from standstill would use gas or gas/electric in the way an Ebersbascher would use diesel.....ie better than leccy.... a combi working on gas is a pretty efficient machine.....as you say, leccy inclusion is an later develop,ent and a sop to the uk market.....use it as it was originally designed (gas) and its a good unit.... the thing is, some view gas as a precious commodity and are reluctant to use it.... Link to comment Share on other sites More sharing options...
trail66 Posted January 31, 2016 Share Posted January 31, 2016 I had the same issue with a Truma water heater ie it would start to work and heat up then stop after a short time. A fairly common fault I am afraid, we changed the heating element on advice from Truma technical and all was ok. Albeit I checked the resistance values of the removed element they appeared ok. Element became faulty when heated up. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 1, 2016 Share Posted February 1, 2016 bolero boy - 2016-01-31 5:56 PM ...a combi working on gas is a pretty efficient machine.....as you say, leccy inclusion is an later develop,ent and a sop to the uk market.... 230V air-heating for Truma ‘combination’ air/water heaters became available in December 2003 when the Trumatic C-6002EH appliance was introduced. Although this heater was commonly fitted in UK motorhomes (as are the follow-up Combi “E” models) this had no direct link to the UK market. The rationale behind adding 230V air-heating was because EHUs with reasonably high amperage had become the norm Europe-wide. It also provided the potential for the heater to be fitted to large caravans, not just motorhomes. The Truma heater fitted to the Original Poster’s 2012 Hymer motorhome could not be retro-fitted with Truma’s “CP Plus” control-panel without its printed-circuit-board being replaced and, without the CP Plus’s ‘boost’ capability, water-heating and showering techniques like Brian Kirby and Tracker have described need to be employed to maximise the use of the limited amount of hot water available. It’s worth mentioning perhaps that retro-fitting a CP Plus panel to even a ‘CP Plus-ready’ Combi may prove impracticable. My 2015 Rapido 640’s gas-only Combi 4 COULD have its analogue dial-type control replaced with a digital CP Plus panel, except there’s no room for it where Rapido has chosen to site the dial-control. 2016 Rapido 640s have a CP Plus panel but this has been repositioned over the entrance-door where there’s more room. Link to comment Share on other sites More sharing options...
bolero boy Posted February 1, 2016 Share Posted February 1, 2016 the boost function seems to just cut out space heating (if both this and water heating are on) until the water has come up to temperature and then space heating is resumed.... its no different than the 'manual' control many adopted to make the most of their combis.....ie, gett your water heated first.....and then switch to space heating.... doing it the other way round would result in hot water not being available for 80 mins (or so) as mentioned in a post earlier.... i did say that retro fitting of cp plus would require a pcb swap as well as a control panel change. the boost function doesnt really acheive much but the manual control of fan speed is a significant improvement when running on 240v. Link to comment Share on other sites More sharing options...
hmpoliveira Posted February 1, 2016 Author Share Posted February 1, 2016 Dear all Thank you so much for your replies. I decided to take my van to the garage since they're in touch with Truma about this issue. I understand that many people has the same complain, which is of course very sad. I hope a nice solution pops up... Link to comment Share on other sites More sharing options...
Tracker Posted February 2, 2016 Share Posted February 2, 2016 If you heat up the water to full temperature, turn the heatt off and fill a bucket, or buckets, of known capacity until it runs cold that might give you an idea of the volume of hot water available. The biggest problem is that as the hot water is used so it is replaced with stone cold water which only serves to dilute the remaining hot to the point that it is no longer warm. Good luck with Truma! Link to comment Share on other sites More sharing options...
bolero boy Posted February 2, 2016 Share Posted February 2, 2016 very true, Rich..... which means, for two people, you either have to get both 'done' by eking out the firsts tankful of hot, or the second one has to wait until a second tank is heated....perhaps a twenty min wait..... we tend to employ the first method as i am fairly brisk in the shower, which means (even with a single tank) OH can (relatively speaking) take her time......im generous like that! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 2, 2016 Share Posted February 2, 2016 hmpoliveira - 2016-02-01 10:02 PM Dear all Thank you so much for your replies. I decided to take my van to the garage since they're in touch with Truma about this issue. I understand that many people has the same complain, which is of course very sad. I hope a nice solution pops up... The more recent “Combi” heaters fitted with the CP-Plus control-panel go some way towards improved water heating. But starting off with just a 10 litres-capacity ‘tank’ of hot water, that starts to be cooled down by cold water entering the tank as soon as the hot water begins to be drawn off, has unavoidable limitations when it comes to showering. As long as your heater has no actual fault I’m afraid there’s no miracle solution, but adopting a suitable procedure (as suggested above) should allow a couple of successive and satisfactory showers to be taken. This 2013 caravan-related discussion may be worth ploughing through http://forums.outandaboutlive.co.uk/forums/Caravans/Caravan-Chat/Truma-Combi-4E-Heater-Problems/32616/ Link to comment Share on other sites More sharing options...
lennyhb Posted February 2, 2016 Share Posted February 2, 2016 The Truma C4 & C6 are pants when it comes to hot water compared to the older C6002. The OP's Hymer will have a C 6, if the hot water is set to 40 deg once heated the hysteresis on the thermostat is very with and the heater will not turn back on until the water temp drops to 27 deg, I find this makes the 40 deg setting useless. When the Hot water is set to 60 it will heat up and maintain temperature as expected as the 60 deg thermostat has only a small hysteresis. Also when set to Heating only the hot water will take a couple of hours to get up to temperature, when set to Heating + Hot water the water still takes 1½ hours to get hot. I fitted a CP- Plus controller in my van this allows you to select "Boost" on the water setting, all this does is to turn the heating off until the water is up to temperature. Once you understand how these heaters work it makes them more usable, but having to run the water at 60 does waste gas & water. Link to comment Share on other sites More sharing options...
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