I have a pressured heating system fueled by oil. When the boiler is on the burner never pauses or hibernates for 5-10 minute intervals; it just burns the oil for the full duration the boiler is on for. I have a thermostat in sitting room which is working and is set 25 but this does not seem to kick in. I had the burner replaced last year and wonder if this has anything to do with it. It really is like a boiling kettle that does not switch off when the water is boiled. Can anyone advise problem and solution?