I would imagine that a wood chip stove is an expensive way to heat just a couple of rads. Would you consider buying a stand alone Waterford Stanley wood burning stove (there are some other very nice small stoves by other makers too), have it heat the room only, as an alternative to heating rads and then have your main heating/ hot water requirements met by a small combi boiler/ oil boiler. The wood stove is considered eco friendly as the fuel is carbon neutral and burns clean. Such a stove (depending on size of course) could be got, complete with flue for €1500 or less but a wood pellet burning stove with heat exchanger would cost a multiple of that.