Hi @jonnyd and welcome. I won't try and repeat all the good information on the forum but I did the same as you and went from storage heaters to an ASHP with radiators. It's much, much better at heating the house and also looks it will be a lot cheaper, although it's early days for us. We are also EPC D rated and about 160m2.  If you do the obvious things (loft insulation, draught proofing) you should be fine. 

In terms of costs, I would agree you should get about half back via RHI.  

Do you have a suitable place to put the outside unit?  

Good luck with the move and if you want any details about my quote, costs, electricity usage etc., PM me. 

Kev 

@kev-m - thanks I might be in touch about the details when I get a bit further down the road with quotes etc.

yes I’m pretty sure there is space at the rear of the house for the outdoor unit.
The EPC said there are no gains to be had from more insulation, but will double check when we get in. It’s fully double glazed, and other draughts are as yet unknown but we’ll be jumping on them sharpish. One known draught i suppose is the chimney in the living room. Current owner uses a wood burner (chimney is unlined) but as we won’t use that we’ll need to get it closed up properly.

@jonnyd, looks like you have plenty space there.  We have a wood burner and a solid fuel stove.  A lot of people with ASHPs seem to have them and i think they can be a useful supplement when it's very cold.  The heat loss calculations that need to be done for RHI make allowances for chimneys/flues. 

I’ve heard back from a couple of companies now, and also looking into solar PV, and (finances permitting) a battery as well.
I’m not sure if we’ll be able to afford it all, but along with our Nissan LEAF which we’ve had for years, a setup like this would be very satisfying, and help us to use as little grid electric as possible. it might be that we go for solar and a zappi charger to charge the car rather than the additional home battery, but let’s see!

A slight aside this. The extent of the questions everyone considering a heat pump has to ask is indicative of how far the industry has to go to make them a successful mass market product.

I doubt whether any of us would feel the need to get so involved over a decision about a gas central heating system. We would just assume (probably correctly) that it would work as expected.

We are used to a world where complex consumer products that we don't understand just work. It's unsettling where we have to familiarise ourselves much more with a product because of the real risk that it won't perform as advertised. When I say "the product" I  mean the overall installation. Most failures are because of poor design, specification or installation. Heat pumps themselves generally function correctly.

Mike

Hi Mike,

As you correctly point out, the problem in the vast majority of cases is not with the equipment.

Over my career spanning 50+ years, I have worked on many highly complex systems and equipment, but always managed to leave behind a happy client by utilising my knowledge and experience to achieve the desired results. Over the past 20 years or so I have been concerned about the quality of many of the young Engineers with whom I have worked. In some cases I was having to teach them the basics, things that I learned when I was an apprentice all those years ago.

It is no use just training people on pieces of equipment, they also need to be trained on how systems operate and how to apply the basic laws of physics to identify problems and arrive at solutions. Engineers need to be shown how to pay attention to detail, because as the saying goes 'the devil is in the detail'. 

Another area of concern is the number of 'cowboys' who jump on the wagon when there is government subsidies to be milked for all it is worth.

Eventually the training may improve and the 'cowboys' become identified, though I am not holding my breath.