the bonus with duotec2 i recently found out is that you can use it on LPG or NG and it will organise itself without us interfering with it. We have just changed 4 boilers last week in caravans where they came ready for LPG but the site is NG. Charged £200 dayrate to change over and commision, only took 2 hrs as it was duotec out then duotec in. They seemed happy with that so have asked us to connect up all the services to all the new caravans that are arriving, not quite sure what to charge yet but they have been charged £650/caravan by the previous plumbers (in & out in a day), and theres 36 to do on this site aswell as another 12 sites all over the country that they have asked us to price for.