Does my espresso machine have air in the lines?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by NickR »

Tried steaming milk on Classika. When I switched to steam, I opened the steam valve, purged for 5 secs, closed, and heard a hissing noise near the top of the machine. Waited a minute, and when it kept going on-and-off, I decided to restart purging, waiting, purging, etc. Steamed milk (went well). Hissing went away after steaming.

Then, I turned the steam off and, following Clive's instructions, opened the steam wand and brew lever until water starting coming out of both. That went as expected.

Then, a few mins later, I activated the brew lever. Water came out pretty normally, but I heard just a hint of what I think was bubbling for about 20 seconds, which subsided thereafter. I backflushed, and engaged the brew again, and same thing.

A bit nervous that I damaged the machine. Which would be upsetting considering I followed instructions.

(1) Is that a sign of air in the lines?

(2) If so, how do I fix?

Supporter ♡

#2: Post by Nunas »

I don't have a Classika, but my best guess is that yours is normal. The Classika is a well-built, dirt-simple, single-boiler dual-use espresso machine. If you don't have water dripping from underneath, then chances are all is well. As for what you're hearing, the Classika has a PID-controlled boiler. A PID typically switches on and off according to a complex algorithm to reach/maintain boiler temp (and therefore pressure). I think you're likely hearing the water boiling around the heater as the PID turns it on and off. My Synchronika makes a similar noise. As for air getting into the system, this would be unlikely. The vibe pump draws water from the reservoir and pumps it into the boiler. The boiler, of course, has air in it near the top, to enable steaming, but since the brew water is drawn from near the bottom, I can think of no possibility of air entering the brew water path. Hopefully another Classika owner will add a post on your thread.

NickR (original poster)

#3: Post by NickR (original poster) »

This was extremely digestible information and I sincerely appreciate it. This answered my question and educated me a bit on the machine. Thanks very much!