I moved into a house during the summer with a 3 year old Glow worm ultimate 35c combi boiler fitted. We had it serviced at the time. Now it's winter I'm wondering if it is working correctly. What temperature range so they normally cycle over when running the heating. I have notice initially the boiler reaches 60C before burner shuts off but it then let's temp on boiler drop to 35C before reigniting the burner often then cutting out again around mid 50C letting system pump till it drops to 35 again. Is this the normal running of this boiler or is it letting system cool too low before firing back up. It seems to mean the rads just start to get hot then cool right off again before boiler fires back in again this is while system is still calling for heat and room hasn't reached temperature.