Can anyone tell me the height to have the probe on a CO room safety check the appliance is an EFEL oil stove (vaporising appliance). Im using a Anton sprint V2 analyser. I have the analyser set to CO room safety check and then i selected appliance to boiler (open flue) but how long do i have to have the stove on before i do the CO test and what hight does the probe have to be at while test is taking place can anyone tell me please.