Running hot water tap and steam - help or hurt in re: Scale

[WR]

I remember seeing a post a while back and I can't find it... We pull pretty much exclusively straight espressos from our Vetrano and very rarely open the steam or hot water tap. Will this increase the amount of scale (and the frequency with which I should descale) or keep scale low as the fairly fixed volume of water in the boiler can only give up so much solid? In other words should I run off hot water every week to refresh the boiler or just look at the boiler as an HX heating device and forget about it (and maybe empty and reheat for the occasional cappa)? Thanks -W

[another_jim]

Steaming can create limescale in boilers even when using the softened water -- the pure water steam goes out, the minerals stay in and gather. Running water or espresso will increase scaling in proportion to the amount of water used and it's mineral content.

Google on the "insanely long water FAQ," to get (insanely) more detail.

[HB]

If I were rarely using the boiler water for steam, rinsing, etc., I would be tempted to fill it with distilled water and be done with it. A quick tee on the input line and a two stopcocks is all it takes. Top it off every once in awhile and never worry about scale.

PS: The Resources page has a link to Jim's insanely water FAQ under Reference.

[cannonfodder]

I dump a couple of cups out the water tap two or three times a week just to keep the mineral concentration down. Just for fun, get yourself some water hardness test strips of kit from a swimming pool supply store. Check your water hardness. A month later draw some water out of your boiler and check it to see how the hardness has increased.

[WR]

Filling the boiler with distilled is a really interesting idea and the payoff of never having to descale would be great. Short of that, I suppose running a few cups out the hot water spout on the rare occasions when I steam will help keep the scale down.

I'll check out the water FAQ. Thanks guys.

[miKe mcKoffee]

If I were rarely using the boiler water for steam, rinsing, etc., I would be tempted to fill it with distilled water and be done with it. A quick tee on the input line and a two stopcocks is all it takes. Top it off every once in awhile and never worry about scale.

Wouldn't filling the boiler with straight distilled water defeat the auto-fill sensor causing it to think the boiler was low and continue auto-filling to over filled state until there was some mineral content in the water?

Or do you mean partially fill with distilled water mxing with existing water with minerals for an overall lower mineral content?

Or did you in fact mean straight distilled water and disable the auto-fill?

FWIW though the thought of descaling a direct connect HX machine boiler was intimidating with the help of the descaling thread it was in fact a piece of cake.

[HB]

Wouldn't filling the boiler with straight distilled water defeat the auto-fill sensor causing it to think the boiler was low and continue auto-filling to over filled state until there was some mineral content in the water?

You're right, pure distilled water would fool the auto-fill, though it wouldn't take much regular tap water to make it conductive. Disabling the auto-fill would be unwise without a sight glass.