Learn how to clean or replace the vacuum relief valve in a Profitec Pro 700 espresso machine. Symptom indicating need for service is continuous discharge of water/steam from fitting at back center of drip tray. Be aware it's normal to hear some hissing and have some moisture discharge as the machine is heating up to full temp. If discharge continues when boiler temp is above 212F/100C, the vacuum relief valve likely needs service.
Profitec Pro 700 How to Clean or Replace the Vacuum Relief Valve