Heating water to kill any bacteria etc

[Harry Bloomfield]

I normally heat it for an hour (i just press the one hour button once no timer settings so i use as and when) but could click for another hour which should make it reach 70 degrees which I think it's set at. A lot of electricity though. I haven't heated the water for four months, over the summer.

Not much cost, when spread out over that many months. In your present circumstances - I would let the water heat to maximum, then run it all off through each outlet in turn, to flush all of your pipework clear of any Legionella. I would also check to make sure there are no dead legs in the system.

 

[Madrab]

I believe the understanding is that once heated to 60Deg then it can be maintained at above 50deg, that will stop any further multiplication and slowly kill any bacteria that's left. That would become tedious though as ever time it is used then the temp would need to be raised again. It's also key as to what element, if there's more than one, is being heated, therefore how much of the cylinder is being brought up to temp.

I would suggest that if a hot water cylinder isn't being used at all for extended periods of time, that it could be drained and then flushed prior to re-using.