Central Heating

Hot water using Greenstar Heatslave oil fired 25/32 condensing combination boiler

Rob Wood 05/05/2026 - 8.05 AM

Hi, we've moved into a house that has a Greenstar Heatslave oil fired 25/32 condensing combination boiler and has a Hive heating and hot water controller. I've read that oil boilers don't instantly heat hot water the same way gas combi boilers do and some pre-heating is required if I've understood this correctly. Question is, if the heating is set to come on anyway, do I need to also set the hot water to come on to get hot water or will the required pre-heat happen when the heating comes on? Presumably in summer when the heating is not set to come on, I would need to set the hot water to come on? Any advice gratefully received. Thank you.