Question (Northern Ireland ?)

Golden_Anemone

Ticked wrote: »

This is something I hadn't considered, so I took time to think it over. I don't consider there was any risk of Legionella, the water only dropped to 30C when the boiler wasn't running at its usual 65C, ie., from 10pm till 6am and 9am till 4pm. Doubt if anything could develop in those times, and if it did, would probably be killed off at 65C. Considering that ( in our case) the boiler isn't run all summer and the domestic water sits at ambient for several months, we're probably at more risk then. Electric shower and instant water heater provide hot water in summer. Anyway, thank you for your input, it did make me think!

I was referring to the OP's initial question in which she was talking about running her heating constantly at 30°C which is within the temperature range at which Legionella can occur. When heating isn't run all summer the water temperature is too low for Legionella - the bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C.