Heat pumps are obviously great in many ways. But fitting one is a big deal - they are quite expensive, they take a lot of work to fit, really require extensive additional insulation, and there are all sorts of caveats to them that mean they aren't a straightforward replacement for a boiler.
So i'm slightly mystified that we basically don't hear anything about fitting drainwater heat recovery [1], in which the lukewarm drain water from your shower is used to pre-warm the incoming cold water. It's extremely simple, pretty cheap, simple to fit, and can recover ~50% of the waste heat, of something which is tens of percent of the energy consumption of a household.
By all means, get a heat pump. But get a heat exchanger on your shower first!
So i'm slightly mystified that we basically don't hear anything about fitting drainwater heat recovery [1], in which the lukewarm drain water from your shower is used to pre-warm the incoming cold water. It's extremely simple, pretty cheap, simple to fit, and can recover ~50% of the waste heat, of something which is tens of percent of the energy consumption of a household.
By all means, get a heat pump. But get a heat exchanger on your shower first!
[1] https://www.energy.gov/energysaver/drain-water-heat-recovery