I was asked on my last power flush job last week if most customers leave the flushing until winter time, well to be honest they do was my reply
but that really is not the ideal time to flush the system, the last two winters have been terrible with many heating systems going down if I’m going to give any good advice on this subject I would say sooner than later, apart from anything else when the weather is warmer generally the system will be free and moving,
I personally would not wait until it gets cold! As that’s when the majority of people do then you could be waiting days to get someone to look at it. So avoid the rush hour in life where ever possible.
Also, start your system and run it up during summer, think of it like a car, if you dont start it up now and then it just won’t want to start at all eventually and that will be when you need it!