We had a Grant Air Source Heat pump (Aerona 13Kw) fitted 11 months ago.

We live in an extended semi now 5 bedrooms 152sqm and replaced an oil boiler with ASHP and had all 13 radiators replaced. We have a Hive thermostat.

The installation was traumatic as they tried to do 3 days work in 2 and after a few niggles we finally got the installer to put things where we expected them to be apart from the controller which is sited in the same small room as the water tank, buffer tank (volumiser) and expansion vessel.

We have been pleased with performance in terms of heat and hot water. We have never run out of hot water (the test will come this week when we have our first overnight guests since the pandemic)

Initially we set the thermostat to 19 in the day and 17 at night and soon realised that it took too long to get back to 19 after dropping at night so we then set it to 19 all the time and we have recently changed it to 20 as our son feels more comfortable at this temperature. The heat pump coped with this very well until the really cold few days in February but since then we have had the volumizer upgraded to one with a thermostat. We have had new windows and the house is mostly well insulated.

We have monitored our electricity use and it varies from 12 Kwh on a hot summers day to 86 Kwh in the really cold snap in February. This is all electricity use not just our heating. This still represents a slight reduction in expenses after comparing it to our oil costs. Our oil consumption was likely to go up as we have now both retired and are at home more so we would have been likely to have had the oil boiler on more.

Having followed some of the discussions on the forum (and if I have understood correctly) it is possible that our weather compensation is not working well as the controller is in a room that measures 5 degrees higher than the rest of the house. And we have a buffer tank although I didn’t understand why this was considered undesirable.

So in essence we are very pleased with our ASHP and its performance so far. It is great not to have oil anymore. Generally we ignore the heating and it ticks along nicely keeping us warm. We are also getting RHI.

It has certainly been a learning curve as we needed to move away from the “twice daily heat your house by boiler” mentality.  Biologically I think we have got used to years of twice daily fluctuations in the house temperature and I think we still expect that. There have been times in the evening when I think I am cold but then checking the thermostat the house is 20 degrees.

I wanted to post this to offer reassurance to other people that ASHPs do work well.