We have a Biasi M90F 28S combi boiler (about 4-5 years old now). Over the Summer it was set to DHW only and we put the CH back on in October. It has been behaving strangely for the last month or so. The basic problem is that the ignition flame fires up for 30 seconds, dies down and then fires up again a minute or so later; this can go on for about half an hour (usually just after the auto timer switches to off). This can happen when the room thermostat isn't even calling for heat and/or when the boiler Auto/Timer setting is Off. The only way to break this cycle (usually) is to turn the dial to DHW only. We did a reset which seemed to help for a while. We have also tried various settings (1-7) on the CH dial, but it still seems to think it needs to heat the CH water supply. I am no expert on these matters but it seems like our boiler is doing a lot of unnecessary work and, as it's in our bedroom, it can be quite disturbing. Any advice would be gratefully received as we don't really want to be without a boiler at Christmas and/or footing an expensive repair bill. Thank you.