Warm water on tap post soft

[Binnie]

If the water is kept cool its a lot less of an issue, it'd just be your radiator that is the risk. also leigonella is anaerobic, so shutting the valves can actually make the problem worse.

I don't know if you could use a clear peice of hose/glass tubing and UV sterilise the water as it's being fed round the loop? i think it would work, but i've never seen it in the flesh.

Unfortunately i'm responsible for legionella control at my work (among my many other duties) and i'm sorry if i'm boring you, it's quite a boring subject tbh.

Raising the water above 50c would eliminate any leigonella present btw.