Descaling (as often as you need to)

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Checking, cleaning and replacing the shower screen and group gasket…from the perspective of the inexperienced user, but it does show how easy it is for anyone to do! (my comments in italics)

Now i realise that alot of this is just experience So, how to fix this? I figure experience experience experience. First step - perform the tasks i've been afraid to perform before. Namely Descale and cleaning the shower screen - both of which i've never done before.

After a previous post on another forum about how often i should descale, the answers varied but i got the impression of around 8 months to a year. However, seeing some issues users have had and talking to everyone at the second meet, i've decided to do it. I followed the instructions which were quite simple and although it took maybe 2-3 hours, its now done. The citric acid that i eventually flushed out from the boiler was a little greenish but no flakes / chunks. I ended up flushing the boiler out with fresh water about 5-6 times afterwards just to be sure. Brilliant job done and now i'm not worried about it so much.

Also, I've heard that HX machine owners like ourselves that don't use the boiler much for hot water, need to descale the heat exchanger more importantly (and regularly) rather than the boiler. Easier and quicker. I'm sure I may be corrected on this though

Absolutely right

I tend never to use the boiler of an HX for hot water. 2 reasons.

  1. Again as you don't need to descale it and as long as the autofill doesn't kick in, can just get away with descaling the brew path. It can however be a good idea to drain down and refill the hot water boiler after a brew path descale, just in-case any descaler has got in there….many machines cycle the autofill when they are turned on!
  2. I can taste the copper in water boiled in an espresso machines HW/steam boiler for hours and hours and I find this taint of the water unpleasant. The stuff from a kettle tastes far superior. For machines with stainless steel boilers, like the Isomac Millennium, this is not so much of a problem….but it's still more stale than water from a kettle.

It's difficult to know how often to descale, but for London every 3-4 months would be an idea for the brew pathway. If you don't use the boiler for water, then once per year or even 18 months!

just reading through the difference between brew path and boiler descale… so doing a boiler descale as you wrote on the manual mean that you've done a brew path descale as well?

Yes. Doing the Heat Exchanger pathway is a different matter and may need to be done more often, every 4-6 weeks in a hard water area, less in a soft water area. Simply mix up a smaller amount of descaler in a jug (300 ml and 25gm citric acid), place the feed tubes in the jug and draw brew water through the group (step 6), backflush a few times, wait around 15-20 minutes, and then flush thoroughly with fresh water and backflush a few times." For heat exchanger pathway, read brew pathway. It's possibly that if the autofil to the main steam/hotwaterboiler goes on, then you may have to drain it down and refill it.

I will just add one thing at this point…I often read of people recommend disabling (temporarily), or otherwise tampering with the boiler autofill control, to effectively get the boiler to overfill for descaling. I don't much like the idea of this, I think it's potentially risky and unnecessary (if there is any scale above the water line, it will have no significant effect) see If you are are thinking of trying this, be very careful and ensure you know exactly what you are doing