The question is in the title I suppose. We have one of the last X244 chassised Hobby 600 series (650EC) with a Fiat 2.8 lump. They started making ours in 2005 and it wasn't first Reg until Sept 2007. I was reading the latest edition of MMM last night and in it, there was a readers submission about their Hobby of a similar vintage although it was a different model. It was stated in the article that the model had a waste water heater element in the tank. We have had our 'van for two years and up to now I haven't found such a accessory. Was it a standard fit in 2005-6 or was it an optional extra?