Use of Citric Acid to Descale

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
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#1: Post by dougmg »

My Alex Duetto manual discourages descaling. I imagine this recommendation is not unique to the Duetto.

The manual cites the damage that can be caused by descaling.

I was going to use Citric Acid in my Duetto.

Thoughts? Do you use Citric Acid? Have you had any problems.
Thank you for any input

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#2: Post by Nunas »

If they say not to use it, I wouldn't. We have very hard water here. Before we put in the whole house softener, the washing machine and the dish washer were covered with scale. We tried vinegar, the traditional method...nothing. We tried CLR...ditto. We used citric acid and it was like magic. It's very powerful stuff. The two machines are mostly stainless inside, so no corrosion issues. Alas, the discharge pump on the washing machine did not like the citric acid and promptly gave up the ghost. That's my experience, yrmv!

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#3: Post by OldNuc »

You will be much happier running the machine on pure water and skip the periodic acid rinse.

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#4: Post by another_jim »

The danger is that flushing the brew boiler of descaling solution can be tricky. They are typically .75 to 1.5 liters in size, and will take a very long time to flush if you are using the pump. The alternative is to remove a fitting from the top and use a siphon to fill and empty the boilers. This is easy for the steam boiler, since you can remove the vacuum breaker. On the brew boiler, you're dealing with 12 bar pressure fittings, and they are harder to remove and reattach.

In other words, if you are not comfortable with opening the machine up and dealing with pipe fittings, you probably should use non-scaling water. On the other hand, most people who post here are have done basic maintenance on their machines; if that is where you are, descaling is no harder than swapping out a vibe pump or pressurestat.

Using citric acid to descale has dangers based on concentration. If you go with usual two tablespoons per liter, you should be OK; if you go higher, you'll get an awesome descale, but aging seals or heaters can get damaged.
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#5: Post by BaristaBoy E61 »

I have successfully descaled our Alex Duetto III with Citric Acid and afterwards the machine has worked as well as it did when it was new - without any problems.

As Jim has said, watch the concentration when mixing and flush till water is completely clear!

This was done without any disassembly that I was sure that I'd have to do.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

dougmg (original poster)
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#6: Post by dougmg (original poster) »

Thank you everyone. I appreciate it.

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#7: Post by Ciaran »

I would add that you could neutralize the residual acid with baking soda after descaling.