I finally got around to descaling my HX for the first time after about 10 months of ownership ... things went well (I think!), but I'm left with a few questions I hope someone can answer. I mostly followed the advice in this excellent thread: Water, Scaling and Descaling with HX machines?

1) Should or should I not backflush with the descaling agent? There was some warning in the thread above about that.

2) Despite holding the vacuum valve up with pliers when overfilling the boiler, I got quite a bit of water spraying from that valve. (At one point, I got water from the over-pressure valve--the large one--as well, but that was likely because I turned the steam wand off a bit too soon). Is that normal, due to the high pressure supplied by the auto-refill pumping, or should I be able to hold the vacuum valve so there's no water at all spraying out?

3) After descaling, I overfilled one more time with fresh water to get whatever descaling agent was above the regular water line. Should I overfill it more than once with fresh water, or is it even necessary to do so (steam has some moisture in it and would eventually flush out the above-the-water-line detergent, or would it?)

4) After descaling, I noticed that my pressure band moved from 0.9/1.1 bars to 1.1/1.4 bars. Normal?

And lastly, 5) is overfilling still recommended, or would it be enough to just regularly fill the boiler, maybe move the machine around a little to slosh the water just a bit above the water line?

Sorry for the basic questions, but this being my first serious machine, I'd rather make sure I do these maintenance tasks properly from the get-go.

If the descaling agent sprayed inside the machine it would be a good idea to be sure none of it got on any of the electrical connections. Since the machine cabinet is stainless that will be fine, but the acid can corrode electrical connections, brass, copper, etc.

If it did, a good plan of attack would be to unplug the machine, disconnect any suspect connections, and use distilled water to clean them, dry them with compressed air, and apply a bit of dielectric silicone grease to them before assembling.

Thanks for the quick reply. Other than the electrical connections (which are fairly well encased in plastic, but I'll clean the ones that may need it), I'm seeing some discoloration on the base the pump is mounted on, and on the boiler ... both may have been there before, but if it's due to the descaling solution, is it something I should worry about/can do something about?

I used the Ascaso solution for home machines, and I'm hoping it wasn't strong enough to do much damage. Either way, the spraying was very quick, and what I couldn't clean up right there dried up pretty quickly.

Nothing to worry about on the motor mount. The release valve opened because you closed the steam wand while the pump was running. When the boiler gets topped off the vacuum breaker will snap shut. If you close the wand you boiler will pressurise under brew conditions (ie 9 bar). Those emergency release valves open at around 3 bar. Always shut off the pump before you close the steam wand. You may want to look at your steam pressure gauge as well. You probably pegged it since most only go to 4 or 5 bar. You can actually damage it if it runs to high. The needle will read pressure even when the machine is off.

The gauge seems fine, I think (reads 0 with machine off). So then the only ("only") thing I should worry about are the electrical connections? Though some of those are pretty hard to get to in this machine; with those, I just hope they either didn't get sprayed on, or that the little solution they were exposed to won't corrode them too much.

Randy G. wrote:apply a bit of dielectric silicone grease to them before assembling.

NO !!

The indicated use of dielectric grease calls for it to be used only on the non-metal parts of a connection. It has been shown to be effective at preventing corrosion when applied directly to the metal connectors as well. Care should be taken when using it in this way, because this application can, in some instances, cause the connection to stop working. A common reason for such a failure is that the grease has not been pushed entirely out of the way between the two points of contact.

Dielectric silicone grease can only be safely used on connectors explicitly designed for it.