If your machine powers on and gets hot, but doesn't build pressure, the most likely cause is that the U-cup piston seals inside your group are leaking. These seals have two functions: they seal and force hot water under high pressure through your coffee "puck" to produce espresso, and they seal above and below the boiler inlet into the group cylinder bore. When you operate your lever to raise the piston, the seals are lifted above the inlet port which allows the heated water to fill the cylinder in the group. As these seals age and wear, they get harder and start to allow some leakage. Eventually they can start leaking to the point that water escapes past the piston rather than being pushed through the coffee, and even allow enough water to escape the boiler that pressure cannot be built. This escaping water may come out the relief hole on the top end of the group, or it may come out through the shower head on the bottom of the group as the machine is heating up. Replacing the U-cup seals typically fixes this problem, and periodic lubrication of the seals will ensure that the issue does not re-occur for many years.

The short answer is: it depends. I have on numerous occassion been surprised at what will hold a seal provided a little massaging is done to the pits and divots in the piston surface. The U-cup seals become quite pliable at higher temps and with the help of a little food safe lubricant, they will seal over some pretty bad looking surfaces. Pitting divots should be sanded to smooth them out a bit, and in extreme cases, could even be filled with a high quality high temp epoxy such as Lord 310A/B (which is slightly resiliant when cured rather than hard and brittle). In the end, it's worth a shot to get by with the piston you have. You will need new seals even with a new piston, so you have nothing to lose by getting the seals first and seeing if your old piston will work.

Espresso machines require a very fine ground coffee to produce espresso. The fine grind allows for the coffee to be packed tight into the portafilter basket and enables good extraction despite the speed at which espresso extraction takes place at in comparison to a drip coffee pot for instance. The tight compaction is also what allows the espresso machine to build the high pressure at which the water is forced through the coffee "puck". You will not be able to find appropriately ground coffee at the store. You will have to buy unground beans and you will need a decent burr type grinder. Blade type grinders will not work. You will need to plan on spending $200+ to get a grinder of sufficient quality. With appropriately fine grind and packing of the basket, espresso should come out at a trickle-just slightly faster than rapid dripping but not really a steady stream.

The Enrico machines have electronic temperature control which actually works quite well. The setting that has the picture of the cup will correspond to the appropriate boiler temperature for pulling your shot of espresso. After the shot is pulled, move the lever or knob to the setting that has the small picture of the steam wand and the heating element will kick back on and pressure will build in the boiler to reach an appropriate level for frothing milk. At each step in your process, allow the indicator light to kick off before proceeding. This will ensure that the machine has reached the desired temperature before you either pull your shot or froth your milk.

With use, particularly steam production, calcium deposits are left behind in the boiler. Occasionally a piece of calcium bicarbonate can break off and become lodged in the pickup tube which leads to the port in the cylinder of the group. This may sometimes be fixed by removing the group and pushing a wire back through the pickup tube to clear the obstruction. In more extreme cases, the tube may have to be removed completely to provide access to the end that is inside the boiler. During a machine restoration it is a good idea to fill the boiler with a strong vinegar/water solution and allow it to soak to help remove the buildup before a more serious issue is created.

It could be that you have a damaged portafilter seal, but the more likely culprit is a casting defect. A high percentage of the CE-14 machines have a casting defect (divot in the sealing face) underneath the rear side of the portafilter seal that allows leakage around the portafilter when a shot is pulled. This defect can be easily and effectively repaired by filling the divot with epoxy and sanding it smooth. Remove the group from the machine to make the job easier, and use sandpaper or a small barrel grinder to clean up the surface oxidation of the divot so that you have nice shiny brass. Don't make it too smooth as you will need some roughness to help your epoxy hold. I recommend use of Lord 310 A/B epoxy for this purpose. Fill the divot to level with the surrounding sealing surface and then sand it smooth after it cures. Alternatively you can braze repair the defect if you have the equipment and skill to do so confidently.