Learn how to diagnose and solve potential issues resulting in the E61 group head not heating up on your espresso machine.
Your machine's E61 group is not connected to the boiler. It gets its heat from what we call a Thermosyphon system. Hot water from the boiler rises and enters the top-back of the brew group and heats it. As it cools, the water exists at the bottom of the group and is directed to the bottom of the boiler where it is heated and starts the cycle all over again. If anything interrupts the cycle, the group will cool.
There are two things that can cause the thermosyphon to fail:
The first is an air bubble that builds up in the top of the tube leading to the group. This is rare but if it happens, raise the brew lever up and purge 8 ounces of water through the group. This should take care of the problem.
Over time, scale can build up in the boilers, tubing and any fittings on the boiler or group. The scale can build up enough to slow down the Thermosyphon or even block it completely. At this point, it is recommended that you send in your machine for a professional descale.
If you try to descale at home, chunks of scale can come loose and will clog up other parts of the machine. If you DO want to work on it from home, start by removing the the tube on top of the brew boiler and checking inside the top fitting on the boiler. That is a normal place for scale to build up.
Espresso Machines: E61 Group Head Not Hot Enough