Not so much a DIY question, but... is there a 'standard' time for a system boiler to heat an unvented cylinder? i.e. Kw per Litre? I want to be sure my boiler is working properly. (My boiler is 30Kw and I have a 250 l cylinder.) I should add my cylinder is not insulated, although I am considering buying a jacket if it will help.
Thanks
Thanks