hi there, have searched this topic and found some replies which have given me some food for thought. basically have a combi boiler, shower upstairs is only barely reasonable temp to take a shower, however I do notice it at this time of year,each year. my question is does the outside temp affect how long it would take to heat the water up seeing as its colder coming in than say in the summer, or is it down to performance of boiler and system etc. thanks for any replies