Industrial electricians have to work on units like shown on the PDF link all the time, but Part P has resulted in electricians having to go either industrial or domestic because of the fees which need to be paid by domestic electricians to their scheme providers. So yes domestic electricians are not normally faced with systems like you have.
Even with an industrial electrician yes likely he could fix it, but at what cost? If I was asked to repair it by my boss I would get in and do it, but if asked if I would take on the job I would back heal it. Just not worth the hassle. With any complex system the method is to get a maintenance contract, that way the firm has to fix it, does not matter if they have to sub contract and get in a Tekmar expert or if they can do it in house, they have to do it.
We have maintenance contracts on the washing machine and TV, originally they were on the fridge freezer and TV but the fridge freezer died and they paid out and we did not need the maintenance contract on a freezer with a 10 year warranty.
It's not that electricians can't fix it, but it's the time it would take. If it takes 2 days to fix then the bill will be likely £600 and electricians know people don't like spending that sort of money, they would likely need to absorb some of the costs, so simple way is just not to take on the job.
If you use
Canadian products which do not offer UK support then expect problems getting it repaired. It's hard enough to get British heating installers to even set the lock shield valve correctly, what chance do you really expect to get one to repair a Canadian product?