It was a green way to replace a 23 year old oil boiler, I just wished we had chosen our installer more wisely

@witchcraft, did running costs ever enter your decision making equation?

Similar motivations here, albeit we put a lot of effort into making sure we got lucky with the installer. Oil boiler was about 20 years old and we wanted to change it at our time of choosing rather than wait until it failed and have to get a quick replacement.

The ASHP was the right choice for us for our heating and hot water, but it's only one step of our overall plan. We've looked at all sorts of solutions for reducing energy consumption, increasing energy production and generally becoming more ecologically sound and efficient; some solutions are amazing but a poor fit for us (e.g. the HERU) whilst others (such as biomass boilers) would have led us down the wrong path for us and yet others simply wouldn't have been able to live up to their hype.

I remember seeing a TED talk about good policy making for decarbonising energy consumption, and it made a really good case for (slightly simplified) moving everyone's energy-consuming appliances to one energy source so that any improvements made in decarbonising the energy generation will have the maximum knock-on positive benefit. That is one reason why I feel electrically powered heating - such as heat pumps - is worth moving to even in situations where there is no net improvement in amount of energy consumed; that energy can at least be made less carbon intensive both now and steadily more so over time. 

@editor Yes but that was before the mad rise in electricity prices - Our domestic battery's pay back time is getting shorter seemingly everyday

Good opportunity to replace oil boiler with ASHP (part funded by RHI). 
we have been on a carbon footprint reducing journey since 2012 when we had solar PV fitted. Everyone on planet Earth needs to do their bit. I recognise I can do my best sooner than some. 
Even with the April electric price hikes, my overall energy costs (home heating and EVs - previously electric, oil and petrol for cars) is the same as it was in 2018. 
So it’s a no-brainer really

For me the whole install was free - I got £5k from the Green Homes Grant and then my dad gave me £5k in return for the RHI payments as he would get a better return than having the money in the bank, so he offered.

I chose an ASHP as it has more heating flexibility than a gas boiler in terms of power sources and allows me to utilise my battery and solar PV to a greater extent.

i like them, i work in heat pump land and i get free samples so i stuck one in at home. The story of mine is here https://www.linkedin.com/pulse/living-air-source-heat-pump-10-years-graham-hendra/ who said heat pumps dont heat old houses?

I moved to an old house in a rural area that had no central heating. Inefficient, undersized electric wall heaters inherited that were useless and expensive to run. Plus a 5kw log burner (love it) in the lounge. Gas is not an option as we are off grid.  An oil fired AGA was also inherited so the oil infrastructure was in place.  However we didn’t want to go with the oil option.  Had we gone with an oil fired boiler wet CH system the quotes were in the £7 to £9k region. A full ASHP system was £14k but with a return via RHI of £8.5k, albeit over 7 years.

So given a choice between an oil fired system and the ASHP that comes in cheaper eventually with the RHI grant covering in excess of 50% and being so much greener the decision was basically a no brainer really.

In conclusion I have to say that whilst it isn’t cheap to run and not helped by current energy price hikes, overall I’m extremely pleased. When we moved in exactly a year ago this month the house was bloody freezing, costing a fortune to produce a small measure of heat and just generally uncomfortable.  Now we are comfy toasty warm and delighted with the decision we made to go ASHP.

MITSUBISHI 11.2 ECODAN supplying DHW and CH to 10 radiators.