Hi. I have an Ideal ICOS boiler in my house for HW and CH. It has been working fine but I have noticed that upstarts in my immersion heater cupboard that it has been a little noisy and hear water running, haven't really noticed it before. Anyway, last few days I have noticed some bangs coming from my boiler. I can't pin point WHEN it happens. I have just been playing with it and cant seem to recreate it. During my testing (with no really knowledge of boilers) I found the following. I turned OFF the HW and CH via the Hive control. - Boiler status turned to '0' I then turned both HW and CH to ON - Boiler turned to 'C' and flashing 'lit light' for about 10 minutes. - Fan then started, I heard the boiler ignite and light went solid. - Within 10 seconds the fan started to slow down, there was a click and the flame went out (well sounded like it) the fan slowed down further until it stopped and the light went back to flashing. It has done the same cycle every 10 minutes 3 times now, but on this last one after it turned off the light is no longer flashing. there are no error codes showing on the front, just 'C' Any ideas on what this is? If it makes any difference upstairs in the immersion road the tank feels hot along with the pipes that are going to it and the circulation pump is running. I am still getting hot water to the taps somehow but cold radiators. Would I be right in thinking that the boiler is not heating the water and the immersion has automatically come on but only heating the HW? I obviously cant tell you how long the CH has or hasn't been working as its been so warm it hasn't been on. Any advice welcome. Thanks, Steve UPDATE: Ok, so I went upstairs to the immersion cupboard and turned the HW and CH OFF from the Hive and the circulation pump stopped. Is that normal or could that be an indicator for something?