So 3 weeks on, Survey done and heat loss from the house is calculated. 8500kwh heat loss annually. We have 10 of the 11 radiators need to be changed so the ASHP running lower temperature gives off enough energy to heat the individual rooms. Thankfully the fixed price install covers any radiators required at a fixed cost.
Our application has gone in for the 5k government grant but we had to get an EPC on the house, luckily we are a high C rated with no loft or wall insulation requirements so should be straight forward application.
Just now waiting for install date.
From the survey if we can run the system below 35degrees rads the we should get 400% efficiency most of the year( except those 3 really cold weeks we get) Then we will likely use about 2700kwh units of electric at current cost 33.5p makes it at about £900 a year for heating/hotwater.
There are gains to be had in our overall system but I won't know exactly what the balance will be until we start using the package. See my previous posts.