Timbrook99 wrote:
It appears that the Relay Box, the HC60NG, of this combo has failed in
my house.

No link with the transmitter, no response on the "push-button" and no
life in the LEDs.

The units are only 7 months old.

Has anyone else any experience of this?

I had one of these fail in exactly the same way after only 48hours of
service.
If you cannot override it with the pushbutton on the receiver unit then it
is scrap.
This was confirmed in a email with Honeywell support person.
I got mine from www.discountheating.com for £82 and they replaced it by
return.
That was last Sept and the new one has been fine since then.