The Valliant Heat pump that was installed is state of the art, obviously high quality and supposed to be very efficient. The installation team worked very hard and effectively leading to a neat and well fitted system. I have operated the heat pump for over 6 months now and although I have been warm this winter it is at a price. The projected cost for running the heat pump was £817 p.a. in the last 3 months the cost has been over £500 so beware. I am still pleased I went with the heat pump as luckily I can afford to be green and the house has been kept warm through a cold winter.