darren you have the same heater as me and 13kg of gas heats up approx 1800L of water at present for me.how the hell are you getting 6000L per 13kg of gas?is yours always on min temperature?
I've had it a bit longer than you bud, longer to play around with it.
When I first got it I was getting about half what I do now.
I have the heat dial not much above minimum, the water dial fully open.
Control the flow with my analogue flow controller on just under 2/6 (I know that's about a third before anyone tells me but my controller is out of 6)
Heater is on the wall behind the door that stays closed in my Trafic. Unflued.
Heat at the brush I don't actually know but just about steaming and temperatures here have been c. 5• here.
You've used, what, 5 bottles Daz?
Took me a few more than that to get mine what I'm on now.
Keep at it, you'll be happy with your use soon enough.