As the title says. I have a conventional set up with a hot water cylinder.. For the last couple of weeks have noticed that radiators are getting hot when the hot water is on. Had the heating on today and it heated the hot water as well. Having googled it sounds like it's the diverter valve in the boiler. But, is there any reason why I can't leave it as it is until summer? It's quite useful like this and may save me money. I would normally put the water on for an hour about now and I don't need to as it heated up earlier when the heating was on. I'm sure there must be a downside to this... So if anyone knows one please let me know. Thank you!