Why does some sensors show -48.30 degrees

If a sensor is not connected it will show up as -48.30c. 
This is common for 0002 (Radiator Forward), 000A (Warm water GT3x external tank), 0008 (Indoor sensor)
You can install those sensors to your pump to get out more info. If you for example add a sensor for 000A it doesent have to be used for Warm water, you can use for Pool temp or other temp you like to get into H60 and your solution. In that case it is important NOT to accept the new sensor in Rego600 service menus, so it will be part of regulations.

Which versions of Rego are supported

Rego 600, 637, 638 is supported. Rego 612 (Dutch model) is unsupported.
For Rego 600 Version 2.26 and later are supported. For Rego 637, 638 all versions are supported. You can check version by holding the mid button for 5 sec. If nothing is displayed, the version is too old.
You cannot update the Rego to later version as it it is also a hardware differences blocking it to communicate. The whole unit has to be replaced to enable communication.

The compressor/add heat hour counters shows wrong

The registers 6C55 to 6C59 of the H60 holds the hours runtime counters of compressor and electrical heater. Rego 600 has a limit where if the sum of Warming + Hot water hours exced 32768 it will show negative negative values in the display. However in H66 it will still shows correctly.
If you like you can reset the hour counter in Rego 600 the following way.
Example for “6C55 Compressor heating hours”. 
For H60
In the web interface of H60, Support menu, run console command execute “XW6C550000”. This will set the hour counter of compressor hours in Rego 600 to 0. You can set it to other hours if you want. For example “XW6C550358” wil set it to 1000 hours. This same principal can be used for all 6C registers you like to reset.

For H66
In the web interface of H66, Support menu, run console command execute “SET 6C55=0”. This will set the hour counter of compressor hours in Rego 600 to 0. You can set it to other hours if you want. For example “SET 6C55=1000” will set it to 1000 hours. This same principal can be used for all 6C registers you like to reset.