I have moved into an old house with a thermal store running off electricity and a multi fuel stove with back boiler. The central heating pump is an vista 40-70(130). The building is single floor with 4 bedrooms and two bathrooms both with showers. we find that some of the radiators at the extremity bedrooms do not get very hot when all radiators are switched on. I think that the pump is not powerful enough to cope. Do I need to get a stronger pump and if so what would be best. Thanks