The Breville Barista Express(BES870XL) was unable to build
pressure. It pushed water fine without the portafilter.
With the portafilter inserted, it formed a puddle on the
counter. Buying a new espresso machine because of my poor
technique didn't sit right.
Here's a shot being pulled under pressure. The leak from the solenoid valve on the right
is not by design.
Here's under the hood. Water enters the solenoid valve
assembly from the bottom left. Some
combination of the (steam | hot water) switch and the shot pulling
button control the valves (What happens if I try to pull a shot while using the
steam wand? :o ). Water destined for the group head will only reach the end of the valve
assembly under pressure if both steam and water valves are closed.
(If anyone knows better please email me or something, I'm just guessing
here). It looks like all three of these circuits (steam, hot water,
and group head) route through the valve assembly and into the
thermoblock at the top of the photo. Anyways, because the valve
assembly was cracked below the solenoid valve on the right, the
circuit couldn't hold pressure and the water leaked.
The culprit. This crack looks like it was caused by overpressurization.
I must have tamped too hard, or ground too fine (maybe both!). I would have expected
the valve assembly to be able to withstand the maximum pressure output
from the pump in the machine, so maybe overpressurization isn't the cause.
