My ecovectors (one in the living room, one in the back room) are quite happy to run at a flow temperature of 50deg. Not that they'd keep my old house warm at those kind of temperatures, and my hot water tank wouldn't like it. But as I've already got gas I use my boiler
As 4 of the rads will replace storage heaters, the wiring for fan assisted rads will be a lot easier that I first thought so these might be an option. The only downside seems to be the cost. I will need 14 rads.
