Heat pump temperature data lags slightly behind the manufacturer controller/app
The maximum delay should be 5 minutes for most brands. For some (e.g. Samsung , it is 2 minutes. This doesn't affect Havenwise operation, as it is not an on/off controller.
For room temperatures provided by a Shelly device, latency is about a minute when powered by cable. When powered by batteries, it updates whenever the Shelly changes by more than 0.5C.
Vaillant onboarding: Gateway serial number not recognised, when it is correct.
Usually this is due to having had a PCB replacement at some point. These heat pumps have an invalid serial number which is mostly 0s. This can be fixed by emailing Vaillant directly - they are quite responsive to this issue.