I’m driving a 63 plate T Range but having some problems with the night heater…
It works…mostly.
But I am currently waiting to load somewhere, switched it on, it worked for about 15 mins and has switched off…why won’t it stay on?
It runs fine if I set the timer to come on each morning, will run for 2 hours…but won’t run for more than 15-20 mins when I’m waiting to load etc
Never driven a Renault, is it thermostatically controlled?? I know mine (Scania) only kicks in when need be, ie when it’s cold (an mines permanently on 2) or when I turn the temp on the controller up.
I drove one for a few weeks as a punishment 
If I remember correctly the night heater doesn’t work manually without the ignition being in position 1, you can program it on the dash for length of duration while it’s set timed, but manually it needs the ignition
Never had a problem with them, spent many a night in them. Always controlled via the interface with the aircon, or by remote on the bunk. Never through the dash.
They turn of when they get up to temp, then kick in when it drops.
Looks like it might be something to do with thinking it’s up to temperature…had it set for 26 degrees, the maximum, but it was 4 degrees outside, and no way was it anywhere near 26 degrees in the cab…
But then it came on and ran fine when I set it on the timer…
Very odd.
This won’t help but I could not figure it out either, but I was lucky, it was summer so I didn’t put to much effort into it.