Conversion of gas boiler to heat pump

Through a switching valve controlled by the heat pump.
With underfloor heating in the garage, this is an absolute efficiency killer for the heat pump.
To what extent is the garage insulated?

The garage has a 24 cm Poroton T14. Frost protection was previously managed via a second heating circuit through the gas boiler. The garage heating circuit only turned on a few times in winter. Actually, except for the gas boiler, I should be able to reuse everything else? Can you connect 2 heating circuits to any air-to-water heat pump?

To be able to respond to this, I lack an overview of the devices and their associated controls. Intuitively, I would say yes, but practically I still advise against operating it that way.

If you care about the ecological aspect, then have an energy consultant/installer or similar come to look at your situation. If it’s about the economy, I would stay away from it. Getting a heat pump is currently a difficult issue. As a manufacturer, we are backlogged with over 7,000 orders.

To be able to respond to that, I lack an overview of the devices and the associated controls. Off the top of my head, I would say yes, but practically I still advise against operating it that way.

What would be your recommendation based on my circumstances?

If so, then in my opinion like this

How am I supposed to keep several rooms (110m²) frost-free with a split air conditioning system? Why can't I use the existing system (existing radiators and the district heating pipe)? To achieve frost protection, wouldn't a flow temperature of 35 degrees for the radiators in the garage also be sufficient?

Does anyone have experience with the air-to-water heat pump Panasonic Geisha? This one is relatively inexpensive. How is the hot water preparation implemented? Are there [square hot water tanks]? The round ones do not look particularly elegant.