Grippatank we have there two man 9 kw set up can’t fault it , dazmonds is also Grippatank he did initially have a couple of problems with it , having had / tried most makes of boilers I feel Grippatank is the best and there after sales service is good , I know some on hear have had bad experiences with them , I think this has been due to a small family business growing rapidly and not being able to keep up with demand , hopefully they are better now with less issues with there supplies chain .