Microgeneration Certification Scheme (MCS)
I've come to the conclusion that the MCS scheme sets a fairly low minimum standard for installers.
What is clear from other comments here is that the experience of every heat pump installation is different. Far more so than with a traditional gas or oil fired heating system.
During our building works I got the impression that the installer was finding his way throgh the installation manual very carefully. In fact they confirmed that although MCS certified they did very few such installations. There have been a number of false dawns in government policy. Installers who got all primed (at some cost) to do more of this work then found it was not forthcoming. They were not building experince on top of the training.
When the MCS inspector visited to sign off the installation he decided that the heat pump we had was too large for the property. It was a 16KW one instead of a 9kW one (physically twice the size). This was duly swapped out (at no cost to us) but how did they get that wrong?
I've been in touch with scores of installers and heat engineers over the past 12 months discussing a lot of renewable heating things, and one of the biggest industry problems is that companies and installers oversize heat pumps for properties because they don't fully understand how they work or they can't be bothered to do accurate heat loss calculations. An oversized heat pump, from what I understand, would be a complete waste of energy and electricity (as well as money).
I'm glad you got downsized at no additional cost for the work (and hopefully you were charged less for the smaller pump). What heat pump do you have?
The general consensus amongst heat engineers is the same as your summation, in that MCS are not hugely beneficial to ensuring that heat pumps are installed correctly.
Mine's the Grant Aerona 9.1kW. COP of 2.66 with air at 7 deg and water at 55deg.
During the period between initial commissioning and the MCS inspection (about 3 months and while other building work was being completed) our first electricty bill was £1k. So I was glad the too big pump was swapped out.
@mike-patrick, that's a hefty electricity bill. Yikes! What's it dropped to now? Have you considered dropping your hot water into the 40s?
@editor Electricty uage settled down to a sensible level. But I have a whole post to do on electricity consumption, mostly arising out of my winter of 2021 experience.
@mike-patrick, I look forward to the post on your winter consumption - ours was insanely heavy.
As an aside, would you consider wiring a review of your 9kW Aerona to appear in the reviews section of the site: https://renewableheatinghub.co.uk/category/reviews