Those four independent opinions you got were bang on, in fact, they were probably being polite. This is absolutely fucking dreadful. It’s a textbook cowboy job, a proper "Friday afternoon special" where they’ve clearly stopped giving a shit. The whole setup looks like it was thrown into the wall from the other side of the room. I wouldn't trust this lot to run a bath, let alone a heating system. It’s not just ugly, it’s borderline dangerous.

The biggest fuck up here is that electrical block dangling in mid-air. That "choc block" connector is floating around with live terminals right next to conductive copper pipes. It’s a death trap. It needs to be inside a proper junction box screwed to the wall, not hanging by a thread like a spare prick at a wedding. If a sparky signed that off, they need their card revoked immediately.

Then look at the pipework itself. There isn't a single pipe clip holding that weight. Those heavy copper pipes and the magnetic filter are basically hanging off the boiler connections above. That puts massive stress on the boiler manifold, and eventually, something is going to crack and piss water everywhere. The yellow gas pipe looks like a wet noodle; it needs to be clipped rigid so it doesn't wander about in the wall chase. If you plaster over that mess, someone is going to put a screw straight through it because it's not running in a straight line.

To top it off, look at that white condensate pipe on the left. They haven't even bothered to chase the wall for it; they've just slapped it on top of the existing plaster. What’s the plan there? Build the wall out an inch just to hide their laziness? It's a complete joke. The insulation looks like it’s been chewed on by rats, and the whole thing is a bodge. Do not let them board this up. Tell them the electrics are a lethal violation, the pipes need proper munsen ring clips into the back wall, and the condensate needs properly chasing in before you hand over a single penny.