arjxh56 Posted March 3, 2014 Share Posted March 3, 2014 On the back of the truma 6e combi there are 4 hot air ducts. Slotted into these ducts is the aluminium ducting that runs around my van. On the duct hole is a little clip that holds the ducting in place. For some reason these are missing on my unit and as a result the ducting popped off during a cold night, melted a cable and a plastic trim inside my van whilst I was sleeping! I have called many places and scoured exploded view diagrams for 2 days now and nobody has a clue where I can get the parts.. Most don't even know they exist! Does anyone know what they are and where I can get some please? They're about the size of a 5p and almost square. They slot onto the plastic rim of the hot air duct before sliding the ally ducting into place. Many thanks Link to comment Share on other sites More sharing options...
arjxh56 Posted March 3, 2014 Author Share Posted March 3, 2014 A very helpful guy at caravan parts has identified them as 34020-2400 set of 3 clips but they have to be ordered in. Anyone know of a place near WF5 that might carry this stock? Failing that I will order them from caravan parts and just have to wait I guess. Cheers Link to comment Share on other sites More sharing options...
arjxh56 Posted March 3, 2014 Author Share Posted March 3, 2014 Kenmore caravans have come to the rescue.. All sorted. Link to comment Share on other sites More sharing options...
spospe Posted March 4, 2014 Share Posted March 4, 2014 I have a 6E unit in my Warwick Duo and all the hot air ducts are just a push fit into the outlet terminals. Do you mean that this little clip should be at the heater end, or the outlet end? Can you refer me to a diagram, or picture of the clips please? Link to comment Share on other sites More sharing options...
arjxh56 Posted March 4, 2014 Author Share Posted March 4, 2014 Hi, I spoke to truma and the duct clips attach to the hot air outlets and when the ducting is pushed into place it stops the duct coming back out. They have a little lip acting like a shark tooth. I have order some through ken ore caravans so that I don't have any more issues with the pipes popping out and the heat melting trim! I don't have a picture but the part number is 34020-24000 Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 5, 2014 Share Posted March 5, 2014 The Part Number 34020-24000 is described as follows "34020-24000 Clips. 3pcs. for T-pipe TS, T-pipe LT, insulating elbow BGI and Combi for improved se- curing of different air ducts" The part is available from several UK retailers. For example http://www.caravanaccessories4u.co.uk/products/gas/heaters/venting-ducting-and-cowls/truma-spare-34020-24000-clips but there are seemingly no drawings/photos of it anywhere. It's possible from the description (and the fact the clips are marketed in threes and have 'non-Combi' applications) that these clips are not fitted as standard to Combi heaters. There's no doubt that hot-air flexible trunking can detach from Truma combination heaters if the trunking is installed so that it is 'pulling' at the heater outlet, rather than 'pushing' against the outlet. Also, if the trunking has not been well secured externally with suitable clips http://www.homesteadcaravans.co.uk/truma-air-duct-securing-clip-75mm/ it may well come loose from the heater. Link to comment Share on other sites More sharing options...
spospe Posted March 5, 2014 Share Posted March 5, 2014 Thanks to you both for the information. In our new Warwick Duo, none of the ducts are secured with clips and some are definitely 'pulling' on the outlets, so it looks like a purchase is indicated. Yes I know that it should be a warranty claim, but sometimes it is easier (and cheaper) to DIY. Link to comment Share on other sites More sharing options...
arjxh56 Posted March 5, 2014 Author Share Posted March 5, 2014 When I spoke to truma the parts were identified as a standard fit and should have been on from new. As Truma don't instal the units they weren't accepting any responsibility for the items being 'missing'. I have also noticed on the duct outlet that there is a little notch cut into them and these clips attach to that notch stopping them moving. I guess this is just another example of bad/lazy/rushed/lack of attention to detail motorhome builds! As discussed in many threads, the build quality of motorhomes is astonishingly poor... Interestingly, I spoke to a few truma service centres when trying to locate the parts and not a single one of them knew what these were or knew if they should be installed. I spoke to a couple of the engineers and they didn't know about them either.. How often are these parts missed out I wonder! *-) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 5, 2014 Share Posted March 5, 2014 Obviously I'm not in a position to argue with your Truma contact, but the purpose of the 34020-2400 part is "...for improved securing of different air ducts". Truma's Installation Instructions for Combi heaters advise that "The 4 connecting pieces on the unit are designed for the 65 mm diameter ÜR duct (part no. 40230-00). Use only pressure-safe ducts in compliance with Truma quality requirements. Other ducts that do not meet our quality standard (particularly with regard to crown pressure resistance, ducts diameter and number of grooves) must not be used." The hot-air outlets of Combis are internally 'toothed' and should hold Truma's own 65mm diameter ducting reasonably tightly. If non-Truma ducting is used, or the ducting's diameter is slightly less than 65mm (which will happen if it's stretched) there's the potential for the ducting to become detached and the 34020-2400 clip should help to prevent this. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 5, 2014 Share Posted March 5, 2014 I wouldn't mind guessing that these clips, if supplied with the "kit", have probably ended up rattin' around in the top of the fitters toolbox or sat on the bench in a box, with the rest of the "left-over"/"what do they do?" bits.... (lol) Link to comment Share on other sites More sharing options...
spospe Posted March 5, 2014 Share Posted March 5, 2014 Thanks to Arjxh56 and Derek for your help. What is a little disturbing about this matter is that the Combi 6E in my 'van is installed in a compartment sealed with a metal lid which is held shut with 6 screws. One of the ducts had come off its outlet and as a result just about all the 6Kw of the heater's output was being rammed into an enclosed space of only about twice the volume of the heater itself. Things got hot! Thanks again :-) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 5, 2014 Share Posted March 5, 2014 pepe63 - 2014-03-05 2:28 PM I wouldn't mind guessing that these clips, if supplied with the "kit", have probably ended up rattin' around in the top of the fitters toolbox or sat on the bench in a box, with the rest of the "left-over"/"what do they do?" bits.... (lol) I'm doubtful that Truma would supply heater 'kits' to major motorhome converters. It's more likely the converter would order x-number of heaters (+ wiring looms) of a particular model and cut and shut hot-air, flue ducting, etc. as required. Although Truma has told arjxh56 that the 34020-24000 part is a standard fitment on Combis, the fact that your new Auto-Sleepers and arjxh56's motorhome lacks those 'clips' casts doubt on that statement. If the clips are supplied 'loose' and need to be fitted during installation, there's definitely no mention of this requirement (nor any mention of the clips themselves) within Truma's Combi Installation Instructions. (Incidentally, the 34020-24000 part is listed in Truma's 2007 catalogue, so it's not new.) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 6, 2014 Share Posted March 6, 2014 This Russian webpage has a clear exploded-view drawing of a Combi heater http://trumatic.ru/state/AB:navID.261/AK:navID.261/AH:-1.202109669186/ The 34020-24000 clips are Number 46 on the drawing and their position on the heater's hot-air outlets will be evident. Besides being suitable for Combis and hot-air ducting parts, the clips can also be fitted to some Truma fan-units. For example, Number 17 on this drawing http://www.ocs-recreatie.nl/files/teb3.pdf It perhaps needs highlighting that, if a Combi heater is closely enclosed (as with spospe's Auto-Sleepers motorhome) and a hot-air duct becomes detached, there's a real risk of the heater overheating as it will then begin to recirculate very hot air within the compartment where it's housed. While the 34020-24000 clips are quite cheap and DIY fitting should be simple (as long as there's access), in spospe's case I'd certainly be complaining to the vendor of his motorhome about the ducting becoming detached, and I'd insist that the vendor ask Auto-Sleepers why the Combi heater is missing ducting securing-clips that Truma advise should be present. (It would also be useful if forum-members owning motorhomes fitted with a Combi heater could check if the 34020-24000 clips are fitted to it. I don't know how visible these things are from outside, but I would have thought that - as the part clips over the end of the hot-air outlet - it should be fairly easy to detect its presence by feel even if it's difficult to see.) Link to comment Share on other sites More sharing options...
andy mccord Posted March 6, 2014 Share Posted March 6, 2014 Another thanks from me also for this thread, my boiler is buried under the foot of my island bed in a compartment with a small hatch, Im pretty sure that I havent seen these clips so I will check this w/end Regards Andy Link to comment Share on other sites More sharing options...
spospe Posted March 6, 2014 Share Posted March 6, 2014 Derek Uzzell - 2014-03-06 7:51 AM While the 34020-24000 clips are quite cheap and DIY fitting should be simple (as long as there's access), in spospe's case I'd certainly be complaining to the vendor of his motorhome about the ducting becoming detached, and I'd insist that the vendor ask Auto-Sleepers why the Combi heater is missing ducting securing-clips that Truma advise should be present. I will bring this matter up with the seller when the vehicle goes in for other rectification work. I was originally going to obtains some of these clips and fit them myself, but on reflection, the best way forward is to make an issue of it and hopefully prevent further occurrences. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 6, 2014 Share Posted March 6, 2014 This late-2012 MotorHomeFacts thread will be of interest http://www.motorhomefacts.com/ftoptitle-132458-duct-heating-and-truma-combi-duct-keeps-falling-out.html Some of the participants in the MHF discussion seem to be confusing the connections between the hot-air ducting and the Combi heater's 4 outlets and connections between the ducting and habitation-area air-outlet fittings (that often have the capability to accept a self-tapping securing screw). It's noteworthy, I believe, that nobody mentions the presence of, or the availability of, the 34020-24000 clips. This is from the ASOC forum http://www.autosleeper-ownersforum.com/t133-auto-sleeper-warwick-duo-modifications In the posting by nimbus on Sun Jun 12, 2011 2:47 pm, there's a photo of a Combi 6E where an additional duct has been added using a black plastic 90-degree elbow, and it looks like a small screw has been driven through the heater's outlet into the elbow to secure the latter in place. This retention method is OK when an outlet is easily accessible (as in the photo), but may well not be practicable for the heater's lower outlets. Link to comment Share on other sites More sharing options...
rolyk Posted March 7, 2014 Share Posted March 7, 2014 The best way to secure a moulded elbow into the Truma outlet is use superglue. Within seconds it's rock solid. It's advisable to back it up with a tiny self tapper just in case the bond fails. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 8, 2014 Share Posted March 8, 2014 I notice that you refer (in your ASOC posting of Thu Mar 15, 2012 9:56 am) to a "small spring clip". Can you say, please, if this is the type of 34020-24000 clip mentioned above that Truma advises should come as standard with Combi heaters and that would (or should) prevent air-ducting from becoming detached from the heater's outlets? Link to comment Share on other sites More sharing options...
rolyk Posted March 8, 2014 Share Posted March 8, 2014 I can't find a picture on the Internet to confirm that the spring clip corresponds with the part number, but it probably does! If it helps I can post a photo of it tomorrow. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 9, 2014 Share Posted March 9, 2014 A photo would be nice, please. It should help other people with Combis decide whether or not their heater has these mysterious little widgets that Truma say should come as standard and, from the occasional report about air-ducting coming detached, should always be fitted during installation. Link to comment Share on other sites More sharing options...
rolyk Posted March 9, 2014 Share Posted March 9, 2014 Here's a pic of the clip. Having just taken it off the duct to photograph I would say it adds little to preventing the duct from being withdrawn from the outlet as it still allowed the duct to be withdrawn quite easily. The best way of securing the duct to the wall outlets is to stretch the duct so that it being held in the fitting by compression. A small self tapper would provide better security than the clip in my opinion. I don't think that motorhome manufacturers, in particular Autosleepers, take sufficient care in installing the Combi unit. Mine came from the factory with only three outlets connected on a 6kw unit. This is in contravention of the the Truma installation instructions with state that all four outlets must be connected. It also states that the wall outlets should be unobstructed, presumably meaning with the butterfly flaps open, even though they can be closed! In my case the unpopulated Combi outlet was blanked off with a plastic bung. This popped out one day and I had 6Kw of heat blasting into the small locker that housed the unit, along with gas pipes and masses of electrical cables. Fortunately I noticed it before any damage occurred. Link to comment Share on other sites More sharing options...
Robinhood Posted March 9, 2014 Share Posted March 9, 2014 rolyk - 2014-03-09 10:33 AM I don't think that motorhome manufacturers, in particular Autosleepers, take sufficient care in installing the Combi unit. Mine came from the factory with only three outlets connected on a 6kw unit. This is in contravention of the the Truma installation instructions with state that all four outlets must be connected. It also states that the wall outlets should be unobstructed, presumably meaning with the butterfly flaps open, even though they can be closed! In my case the unpopulated Combi outlet was blanked off with a plastic bung. This popped out one day and I had 6Kw of heat blasting into the small locker that housed the unit, along with gas pipes and masses of electrical cables. Fortunately I noticed it before any damage occurred. ...I think you will find that this could (depending on which outlet was blanked), be in accordance with Truma's installation instructions, viz: For optimum warm air distribution, Truma always recommends using the 4 warm air outlets of the heater. If only three warm air outlets are needed, one of the lower warm air outlets must be sealed with a blank cover VD (part no. 34310-01). The blank cover must be firmly pushed into the moulded part of the heater until it audibly engages and is firmly seated. Check for firm seating. there is a further caveat in this case, however: If four warm air outlets are being used, a closable end outlet EN may be installed in one warm air branch. If there are only 3 warm air outlets, it must be ensured that if a closable end outlet is being used (e.g. bathroom) a second non-closable nozzle must be installed in the warm air branch. I note however, an implication in the installation instructions that the Diesel fuelled version of the Combi should have all four outlets in use, but I believe AS fit the gas/electric version. (also, though all four outlets are used on the 6E in my Hobby, ALL the outlets are closable. :-S ) Link to comment Share on other sites More sharing options...
rolyk Posted March 9, 2014 Share Posted March 9, 2014 That caveat applies to the 4e. My Combi is the 6e and the installation manual says - In order to prevent heat accumulation when using the Combi 6 (E), all 4 warm air connecting pieces must be attached. The cross-section of the hot air pipes must not be reduced by pipe connections or the like. If an EN end outlet that can be closed off is installed in one of the Combi 6 (E) warm air ducts (e.g. in the bathroom), a second outlet that cannot be closed off must be installed in the warm air duct. It's only on the 4e that one outlet can be blanked off. And, as I read it, the only time a duct can be closed off with the 6e is when it is a branch off a duct. In other words all the four ducts should be free flowing. Link to comment Share on other sites More sharing options...
Robinhood Posted March 9, 2014 Share Posted March 9, 2014 .....hmmm. In the latest instructions, the caveat only appears to apply to the Combi D6(E). (But re-reading it in context, and with the earlier instructions which I have (and are like yours), since the headline does not seem to include the diesel versions, I suspect this may be an error. :-S Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 10, 2014 Share Posted March 10, 2014 It’s always been the case with Truma’s 6kW-output ‘combination’ heaters that none of the unit’s four outlets should be blocked off. An optimised installation for a Truma combination heater in a motorhome would have the unit near the centre of the vehicle, positioned so it cannot become a missile in the event of a serious motoring accident, accessible for basic trouble-shooting, and (reasonably) easily removable if this became necessary. Hot-air ducts should be roughly the same length. Tight curves and elbows in the ducting layouts should be avoided whenever practicable as these will reduce the system’s overall efficiency. Wherever the heater is housed should be very well vented into the motorhome’s habitation area, as lack of ventilation will restrict the heater’s ability to circulate warmed air. Although using the ‘butterfly’ flaps in the end-outlets may be necessary to control the distribution of hot air, this can also reduce overall efficiency. An optimised system should be designed to operate effectively with all the flaps removed from the end-outlets. Truma’s C-Series combination heaters that preceded the “Combi” range had no clips to retain ducts or elbows in their outlets and using mechanical retention methods (eg. self-tapping screws) was impracticable. The C-Series outlets had grippier interior ridging than Combis, but it was still wise to ensure (as I mentioned earlier) that ducting ‘pushed’ positively against the outlet. ‘Pushing’ is best obtained by first compressing the ducting along its length to maximise its cross-section before inserting it into the heater’s outlet. Once the ducting has been inserted in the outlet, if there’s any possibility of it becoming detached, external clips http://www.caravanparts.co.uk/99011-duct-securing-clip-65mm-p-2578.html should be fitted to prevent this happening and to maintain the ‘push’. Stretching the ducting along its length to produce ‘push’ reduces its cross-section, making detachment from the heater’s outlet more likely when the ducting heats up and tries to contract lengthways. If adding ducts (or modifying a heating system) it’s better to have the ducts over long and in compression at the heater’s outlets, than on the short side and stretched. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.