Truma heater offset

my truma heater control  has an offset of minus 5 to plus 5 , what dose that mean  .? Please

Molly, its to help calibrate the actual room temperature with regard to the location of the thermostat.
if the thermosta was placed in a warm prt of the van, say above a vent, then the heater might click off before the whole van had reached the required (set) temperature.
you could place a thermometer close to the thermostat to get the temp at that location and another (say) in the centre of the lounge.
the difference would be the offset required...

Hi I like molly wasnt sure what this was. Where is the thermostat located

ours is above the centrally sited habitation door, close to the van's control panel...
its a small black round plastic thing...
truma combi thermostat

Thanks I get it now

Thanks for the link Chris.  The photo solves a puzzle that has been bugging me for a couple of months.  I found the cap piece on the floor of the MOHO. Didn't have a clue what it was or where it came from.  Can anyone help with the location of the sensor in a Warwick Duo ?
Keith

Just to clarify, if my Truma is set to 20 degrees but stops heating the van when my thermometer reads 18 degrees, should i adjust the offset to +2 or -2? Thank you