Sometimes air gets into the water lines on an espresso machine, either because it is a brand new machine that has not yet had water drawn through it or because it has been to a service centre where the system was drained or because it has been sitting for a while and dried out or because you were just steaming a lot of milk.
When you then try to make a drink or rinse the machine, it is unable to pull water through. If you have a digital display, it will likely say "Ventilate" at this point. If you don't, you might see a flashing red light somewhere on your front panel. There may not be an indicator at all but you know there's a problem because there's no water (or coffee) coming through when you try to run it.
Ventilating a machine is also known as priming. Often, this is a very easy fix. Sometimes the machine will even do it for you automatically.
• The first thing you should do is remove the water tank and confirm that it is full of water. You can also confirm that the water tank is functional by pressing on the seal at the outlet (where water leaves the tank to enter the machine). If water comes out of the tank when you press it, then it should be fine. Do this over the sink!
• Replace the water tank.
• Turn on the hot water tap. On some machines, you have to push a water button and then turn on the steam knob. Other machines might just have a single button and no knob. Check your user manual if you are unsure how to dispense hot water from your machine.
• You will hear the pump engage and soon you should see water starting to spurt from the tap. Wait until it is a steady stream and then turn it off and your machine is now primed. If this doesn't happen within about 30 seconds, stop the tap so you don't risk damaging the pump.
Older machines would often have a tool like a turkey baster that you would use to force water into the lines. You may still have a machine that came with one. If you don't have the original tool anymore, by all means use a turkey baster. This procedure can also be used on newer machines if needed.
• Fill the water tank and turn on the machine and then turn on the steam tap.
• Don't allow the machine to heat up.
• Take the water tank out of the machine and set it aside.
• Fill the tool with water and squeeze it into the water intake.
• Note: If it isn't a perfect seal, water may spill so have a towel ready.
• Warning: You may have to refill the tool and do this again but never let the pump run for more than about 30 seconds.
• You will hear when the pump is grabbing water instead of air as the noise will change.
• Turn off the steam tap.
• Replace the water tank.
• Try to dispense hot water from the steam wand. It might sputter but should quickly start turning into a steady stream, in which case you are good to go. If your machine is still not working, you will probably have to take it in to your local service centre. As always, for any service needs, call a technician first so you know where to bring it and how long it might take to fix and what the cost might be. Perhaps the technician is even able to help you fix it over the phone.