On Demand water heater.

[WanderingWibble’s]

I’m needing to change my heating and hot water systems, my old Truma is unreliable and inneficient. Rather than a tank water heater I am thinking of an on demand water heater (like a combi boiler but without the heating). Has anyone else gone this route? If so results, recommendations, a friend uses one outside, it works well, I need a flue version.