@newhouse87 They would sit on the raised pad or base and the heat pump will be bolted with C clamps as @transparent indicated to the rails. The weight of the pump is sufficient to keep the whole assembly from shifting. Regards, Toodles.

Yes. If 400-450mm is adequate for the distance between the feet positions on your ASHP, then those are fine.

Most people don't bolt them down...
.... whilst a few put a bolt straight through the steel channel and the rubber mass, then into the concrete pad below
which somewhat defeats the whole point of its vibration absorbing properties! 🤨 

If you look closely, there's a recess along each side of the foot.
That's the location where it can be held.

Either drill a hole and insert a long bolt at an angle (as shown in purple),
or else use a steel angle (orange) and a vertical bolt (blue).

Think it should be bolted down as it will be on raised pad though. V strong winds here at times particularly today.

Good to know it can be done without needed ex pensive plumber and spark back to extend wiring and lines. Could not sleep in bedroom it's currently attached to when running in winter.

If I was going to make my own galvanised steel clamps to hold the feet in place,
then I'd start with some roofing straps.

There are two gauges.
The thicker one is about 5mm, which means I have to use a vice and lump-hammer to re-form the angles.

Alternatively, in these far-western realms of England, we still have blacksmiths who will create whatever you wish for 😀 

This is the bracket supporting our 7kW Vaillant. It looks more substantial and is designed for an higher upper weight limit and has no noise we’ve heard so far, not even on the legionnaires cycle.

Interesting photo of that bracket @judith  😀 

That looks to be the version of the Vaillant bracket for walls with external insulation.
It uses 68mm discs to pass the bolt through the outer insulation layer.

The bolt itself is 'glued' to the solid wall beyond the insulation layer using the Hilti HIT-HY-170 chemical anchor.
It's a resin and hardener compound which gets mixed by the flutes on the inside of the nozzle as it gets injected into a pre-drilled hole.

The downside of your installation seems to be the gap left around the 20mm corrugated-plastic conduit which supplies the electricity.
That will need sealing with a low-modulus mastic to prevent ingress of rain.

@transparent it has a virtually clear seal that can barely be seen by eye never mind on a photo. I’ve not proded it (calibrated biro test!) so I’m not sure of the modulus

We’ve got external insulation so it’s the right version of the bracket for us.

Similar bracket to mine but i have no external insulation. Would the external insulation be the reason you have no vibration noise?