We're looking to get rid of our Oil Tank & Boiler. We have a heat pump, do we need both?

So you have experienced winter in the property. How has the system performed during the coldest part of the year? Is the system dual or hybrid? ie: what did the oil boiler get used for? Is it heat pump for heating and oil for domestic hot water? The first thing you need to do is accurately calculate the heat loss for the property (see www.heat-engineer.com and pay for the advanced calculation application @£15). Once you have that and hot water requirements, you can then look at a system which will meet the criteria. What insulation improvements are needed, heat pump size, rad sizes, UFH possibilities, hot water storage, pipe sizes and controls. Remember... Whatever you design the system to reach, is all it is ever going to reach, in terms of temperature... You cannot overshoot... The whole point of such systems is to save energy by getting the porridge "just right". Educate yourself by watching and reading the content available at Heat Geek. Heat pump systems work perfectly well if designed and installed correctly. They are not a box swap solution for forgiving, over sized gas or oil boilers.