Timely topic for me…
I’ve been washing mine with soapy water once a week but yesterday noticed a film of ‘slime’ for want of a better word, covering the inside of the tank and hose. It also had a weird smell. Not unpleasant mould like, just odd.
So now I’m thinking I should do it more often.
I use Volvic and tend to top up as much as I might need in a day.
I’m guessing the lack of chlorine in bottled water and the ambient temperature behind the boilers creates a pretty comforting environment for the aforementioned slime to build up.
I’m fascinated at how @MediumRoastSteam can go two months with no issues, what’s the secret?!