How did you install your heat pumps?

This is the same Grawitschko installation that can unfortunately be found many times in the new development areas.

Better make sure that the part was properly decoupled.

@nordanney why do you need two heat pumps?

Two-family house - one apartment (mine) with underfloor heating and one apartment with radiators. Two heat pumps make more sense (and are not that much more expensive than one large heat pump, which would then have to operate a complex hydraulic system).

what is supposed to be sound-decoupled on an outdoor unit? Logical for wall mounting but for its own base?

That looks pretty strange. The screws on the edge of the concrete will definitely not hold in the long run. And you only really need to decouple the air-water heat pump if it is connected to the house (wall mount or house foundation). We also have our air-water heat pump on a concrete foundation. That was a requirement from the manufacturer. However, in the hole in the foundation, the drainage is connected. The district heating pipe comes from the back into the air-water heat pump. Since that hardly fits properly when setting the air-water heat pump and the pipe is extremely rigid, there are such angled pipes.
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what exactly should be sound-decoupled on an outdoor unit? Makes sense when mounted on a wall but what about a separate base?

You hear it, what should be decoupled ;) . Works well with many units, but some are noisy.

We had ours installed on a concrete foundation with decoupling on the garage (directly at the utility room)... we were bothered by the unit in front of the house... no idea if it makes sense, but it runs quietly and perfectly like this...