OK so jumped in the RR this morning to do a few tests.

FBH fired upon ignition and ran full cycle = good

Went for drive to warm up engine = good

On return sat on drive and turned ignition off & put radio/screen on = good

Selected "Timed Climate" and as expected "Manual Heat" and "Manual Vent" buttons has lit up (not greyed out)

tried pressing Manual Heat (Park Heat) but no response other than an orange surround while touching button - it would not turn orange/on = bad

Went for a further drive, parked, turn off ignition and tried again and same again - annoying

Anybody else regularly use this function to keep warm/cool when waiting for the other half popping into get milk - for an hour! And have any cluesies?

Sorted VIA the WIKI:

Parked Heating
When the ignition switch is in position I, parked heating can be selected on and off using the MID or MFD. When the ignition is off, parked heating can be set to come on at a programmed time or selected on and off using the remote handset. The programmed time is a start time for parked heating to begin within the next 24 hours and is entered into the instrument pack using the MID/MFD.

Once parked heating is on, if it is not selected off it will automatically time-out after 30 minutes. If the engine is started while parked heating is on:

If the engine coolant temperature is equal to or more than the heater coolant temperature, parked heating is switched off

If the engine coolant temperature is less than the heater coolant temperature, parked heating remains on until the engine coolant temperature reaches the heater coolant temperature.

Basically useless as a keep warm heater if the engine already or still warm. OK if you get back from a long walk and want to sit the car and watch the sea but few other uses...

Note: Or get kicked out by the wife and have to take refuge in the cold car...