Hi Yes we have installed many heat pumps, we prefer Dimplex because of quality & simplicity to install. Although they are far from the cheapest. The design of the ASHP system is essential to benefit from COP efficiency. your investment must be into a good quality unit otherwise one major breakdown such as pcb or compressor will wipe out any savings on energy cost.
our website is
http://www.heatology.co.ukDepending on where you are in the UK we can call or recommend an installer