I loved the L5 because it was hot water quick and cheap but quickly realised as you say it was stupid having a gas bottle in the back of a van connected up to a outside heater,yes madness it is not my words but firemans and others a like.I didn`t really look into the risks involved and there are risks with gas,after being warned of the risks i got a proper diesel heater that is designed for the job and is more importantly safe.Some of the work i do i was breaking H&S regs by having that in the van parked on site,sometimes i`m more than a 100mtrs from the van with it running so you could have said i was mad.It showed me hot is the only way as it has to many advantages not to have it,3k is nothing for peace of mind and hassle free hot water.