The control panel does indeed have a holiday mode, but I don't want it going off all together and the slab cooling down too much, I want to try and keep it warm so as not to have to heat it up from scratch again
Chris,
I am operating the heat pump at my place fairly frequently in Vacation (horrible American phrase) Mode and there is no evidence of mass cooling going on. The biggest saver I see is that the hot water tank (integral to the heat pump) cools right down. The default setting with CTC is the same as the Night Temperature Reduction feature which amounts to only -2
oC on normal temperatures.
It is the possibly the simplest option for you?
Regards
Richard