I'm not surprised. I purchased a brand new house and they didn't even offer the option for a heat pump. The government needs to make it mandatory to have one in new builds.

I'm still of the stance that heat pumps work well, if the house heating system is designed/adjusted to accomodate.
Modern insulation, large radiators/underfloor heating? Ideal candidate, you'll hit decent efficiency most of the time.
1930s house with little insulation, and un-calculated radiators thrown in and run at 70'C?
You might as well be using bare electric heating at a lower install cost.

So the push for ASHP/GSHPs needs to be a two pronged attack: Get places ready to receive them, then install them.

The problems are huge upfront costs and lack of heat engineering knowledge of the installers resulting in rubbish installations.

These systems are subsidised via grants to the consumer such as the Boiler Upgrade Scheme paying up to £7,500 towards the cost. A typical air source heat pump, the most popular, can cost from around £7k to £13k. So you have to ask yourself why are they so expensive given they've been around for decades in Europe? It's a nice money earner for the installers and manufacturers.

As a result we're now seeing all sorts of companies suddenly popping up offering air source heat pumps. An example is a local company that fits roofing facia upgrades who now offer heat pumps. Yes they might have bought in the "expertise" but that is where the second problem is; lack of skilled heat engineers.

There are a lot of plumbers that pose as heat engineers. No doubt there are good plumbers but there are, I think, a bigger number that don't know a two port valve from a bag of candy floss.

Many of the installers have been on a one week course by a manufacturer that sells off the shelf packages based on a one size fits all. But that's where it goes pear shaped. For example, installing an ASHP in a poorly insulated Victorian house, telling the customer they're going to save thousands on their gas bill only for their electricity bill to double, triple, quadruple.

These heat pumps can work so long as they are installed by a suitably skilled qualified heating engineer, in a suitable property.

I looked into heat pumps about 15 years ago. I wasn't convinced then and I'm not convinced now because of the stupid costs and lack of skilled installers. In fact having looked into it recently again I'm less convinced now.

Buyer beware.

This You Tube explains why. There's a few follow up videos worth watching but they are a bit drawn out.

Technology Connections has been trying to educate installers about these, especially around appropriate sizing and when to use backup heat (from a US perspective).