Ideal icos condensing boiler. We got home yesterday post Christmas to discover a very cold house. Pre holiday I set heating to come on overnight only. We switched heating from timed to continuous but it didn't come on. Screen said 0 and boiler light was off. However, when I switched hot water to continuous the ignition light lit up and screen said C and both came on. The heating now only comes on if hot water is. Any ideas? I've tried reset and switching off and on! Just wondered if there's anything I can do or if we need to call someone out! We don't have gas appliances so can't be sure if working ok! Thank you