Dennis IT664 Posted July 16, 2020 Share Posted July 16, 2020 Hi can anyone help please? Took my motorhome out for the first time this week. Just a local site in Woodhall Spa. Connected to electric hookup as usual, put heating on to heat van and water. Within 5 minutes red light flashing on heater controls and I lost electrics. Tried resetting 230v breaker but just kept tripping. Nothing else connected to mains so suspect heating element blown. Fortunately 12v system worked fine and used gas heating to heat the van and hot water so all not lost. How can I disconnect the combi boiler (gas and electric type) unit under the French bed till element changed? I can't find a distribution board to isolate the unit. I traced the mains power lead for the unit to a small junction box but all the connections are crimped together. Is there another way. I thought if I can isolate the boiler and try mains electric it would confirm my thinking that it is in fact the element. Link to comment Share on other sites More sharing options...
arthur49 Posted July 16, 2020 Share Posted July 16, 2020 Dennis Not sure I can answer your query but more information might help those more knowledgeable than me! 1. Make, model, age of van? 2. Make, model of heater unit? Link to comment Share on other sites More sharing options...
Agaric Posted July 16, 2020 Share Posted July 16, 2020 Have you a multimeter, if so do a continuity test on the element. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 16, 2020 Share Posted July 16, 2020 Dennis’s motorhome is likely to be a Burstner Ixeo it 664 https://www.outandaboutlive.co.uk/motorhomes/buyers-guide/motorhomes/details/it-664/9309 and built on a Fiat Ducato X250 base somewhere between 2010 and 2014. Heating will be via a Truma gas/230V combination air/water heater - probably a COMBI 6E. I’ve no hands-on experience of COMBI heaters that have a 230V heating capability, but I would have thought that Dennis should be able to ‘force’ his heater into gas-only mode which should at least prevent it from tripping the 230V supply. (In fact, as Dennis has said "Fortunately 12v system worked fine and used gas heating to heat the van and hot water so all not lost”, this suggests that he knows how to do this.) The problem might well be due to one (or both) of the 230V heating elements having failed, but being able to test that hypothesis with the heater remaining in situ under the motorhome’s bed is likely to be challenging. If the motorhome’s 230V system is OK when the heater is operating on gas, but trips out when the heater is put into 230V (or gas + 230V) mode, then the heater is the culprit. But the heater will probably need to be removed from beneath the bed to confirm exactly where the fault lies. Link to comment Share on other sites More sharing options...
Agaric Posted July 16, 2020 Share Posted July 16, 2020 There should be an inline plug connected to the boiler for 230v, disconnect that then you can do a continuity test on the boiler end as the power only goes to a PCB then to the elements, or you can just power up and see if it trips, if it doesn't then its the Truma. It will be an arm and a leg to fix as Derek has said the boiler has to be removed from under the bed, it's about 4 hours work in all plus parts. Myself I would probably diconnect it and just run it in gas mode. Link to comment Share on other sites More sharing options...
Brian Kirby Posted July 16, 2020 Share Posted July 16, 2020 Truma UK are based at Tutbury, NE of Leicester. They do carry out repair work to their items, but whether that remains the case under Covid I don't know. It is roughly 60 miles from you, but if you contact them you may find their rate to repair the heater lower that the cost of removal and repair by a motorhome dealer. This assumes you are happy to remove the heater to take it to them, or take the van to them with the heater in situ. Most of the cost of such repairs lies in the labour to dismantle and then reassemble the various bits of the motorhome interior to gain access to the item to carry out the repair. There isn't usually anything very complicated to overcome, and usually the furniture that encloses items such as the heater is assembled with screws, so it should come apart fairly easily - albeit you may need to remove quite a few screws and bits of the bed! Personally, I think I'd take that route if possible, as I'd sooner have the job done by someone who knows the heater well, than by someone trying to do it for the first time with the maintenance manual in one hand! :-D Just a suggestion, of course! If you could remove everything that obstructs assess, so that a Truma tech can just walk in and disconnect gas + electrics; remove, repair and test; and then reinstall and re-connect, that should help reduce the cost - albeit at some cost to you in time/fuel. Link to comment Share on other sites More sharing options...
weldted Posted July 16, 2020 Share Posted July 16, 2020 With the 240 power off try setting the Truma control panel to gas only, you should be able to select Elec 1 or Elec 2, Elec and gas or gas only. See If it still trips with gas only set. Link to comment Share on other sites More sharing options...
rayc Posted July 16, 2020 Share Posted July 16, 2020 It appears to me that at the moment it is guess work. It is blowing a fuse /trip of some sort, either a MCB or RCD. The OP says " 230v breaker" so could be either. The boiler will have to be isolated from the remainder of the mains wiring by disconnecting it in the box mentioned by the OP. The crimps can always be remade at a later date. The unit should then initially undergo an insulation test with a megger type tester. This will involve a high voltage insulation test between Earth and Live and Earth and Neutral. It is no use doing a continuity test with a battery multimeter. Once this has been done and depending upon what is found it may need stripping down to get access to the element wiring and subjecting the elements to further testing to determine the resistance between Live and Neutral and Live/Neutral to Earth. If the OP wants to run the remainder of the system on EHU he could disconnect the wires in the 'crimp' box and ensure they are safe by insulating them. Link to comment Share on other sites More sharing options...
Agaric Posted July 16, 2020 Share Posted July 16, 2020 To test for a failure of a element you do indeed use a multimeter. You can either do an Ohms test on the element terminals or just set to continuity and test live to frame if you get a buzz then you have a short. Link to comment Share on other sites More sharing options...
Alanb Posted July 17, 2020 Share Posted July 17, 2020 Agaric - 2020-07-16 11:07 PM To test for a failure of a element you do indeed use a multimeter. You can either do an Ohms test on the element terminals or just set to continuity and test live to frame if you get a buzz then you have a short. As rayc has pointed out the fault could be due either to a short circuit, or an earth fault where a much smaller current leaks to the metal frame of an appliance. A short circuit will trip an MCB with no current flowing to earth, but the MCB will also trip if a large current is shorting to earth. A high resistance earth fault will only trip a RCD or a RCBO. The latter two devices may operate for an earth fault reistance as high as 10K Ohms. A standard multimeter will not sound a continuity buzzer when such a resistance is connected across its terminals. As rayc correctly suggests, an insulation test is required to locate to confirm that such a fault is not present. Alan Link to comment Share on other sites More sharing options...
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