I recently had a Worcester 4000 boiler installed to replace an older Combi boiler that was causing problems. While I’m happy with the boiler, I’ve found that the radiators don’t seem to be getting as hot as they did with the old boiler and rooms don’t seem as warm. It’s a big old house and I have a disabled Bed bound daughter so need the heat on most of the day. The radiators were bled and they said they performed a flush as well. The boiler says the heating temperature is 78. Any ideas please?