One of the factors that will determine whether you will spend more on the installation of your Orange heat pump is whether you need a backup for it or not. There are certain pumps that still need to be supported by a backup system. If this is the type that you have or the one that you are looking to purchase, you will also have to think about the cost in terms of the backup, and more importantly, the maintenance and running costs of the backup system. Do not ignore this because it also has to be factored into your costs at some point.