Miele CM5200 coffee machine vapor escaping

Anytime I use the hot or froth milk, there is vapor coming out of the drainage valve. I replaced the drainage valve but the problem is the same. Coffee always worked perfectly without vapor or water dripping from the drainage valve.

Also, the machine have a hard time sucking milk when milk container is past half empty. I also made sure there was no blockage in the pipes. I believe the lost vapor less pressure is what making the machine struggle to suck in milk.

Is there another valve that I don't know of that can be the problem ?

You can open the outlet valve and stretch the spring a little. The problem also exists with other manufacturers/machines with this system.

If the lines are free, the ceramic valve may not be completely open. Maybe also decalcify thoroughly with a good decalcifier based on amidosulfonic acid.

Ok thanks it works now after cleaning and streching the spring in the outlet valve.

At first, I was mixing the drain valve and outlet valve. So I streched the spring in the drain valve but did not work.

Stretching the spring in the outlet valve solved the problem of vapor escaping through the drain valve while usin hot or froth milk.

Thank you very much!