Try this troubleshooting guide:
If your Silvia won't heat up, here are some simple steps you can take to help isolate the problem.
Steps For Amateurs and Smart, Cautious People
1. If the big orange light (BOL) next to the main power switch is steady-ON, but the boiler is not heating up, then the safety thermostat has probably tripped and needs to be reset. After you understand what caused it to overheat, then press the red button to reset the thermostat and the heater should work again. If you can't figure out what caused it to overheat, then you are running a risk of damaging yourself or your machine when you turn it back on.
2. BOL steady-ON, but resetting the thermostat didn't fix it? Likely to be a burnt out heating element. Skip to the "experts" section below.
3. If the BOL stays off when the machine is turned on cold, then the problem is the brew thermostat or the steam thermostat.
4. To eliminate the brew thermostat as the cause, flip the steam switch ON. BOL comes on and boiler starts to heat? Then you can be nearly certain that your brew thermostat is defective. Spend $10 and replace it.
5. Still no heat? Then it is probably the steam thermostat. Replace the stat and try again, or continue below.
Additional Steps for Experts and DaredevilsFurther testing requires a multimeter and some understanding of electricity, thermostats, and appliance wiring. Stop now and get somebody to help you if you don't have all of these.
1. Make sure the machine is completely cool and UNPLUG it. Leave it UNPLUGGED til you are done with all of the following steps.
2. Disconnect the wire leads from the steam thermostat (this is the thermostat on the top of the boiler, on the right side, nearest the pressure valve).
3. Use your multimeter to determine if the steam thermostat is closed, i.e. conducting. Use either the continuity tester, or the ohm-meter. If the machine is cold and you have anything less than full continuity, or any measurable resistance (more than a couple of ohms) across the bare thermostat terminals, then the steam thermostat is bad.
4. If the steam thermostat is OK, then disconnect the wire leads from the two heater terminals in the central, top area of the boiler. Use your meter to measure the resistance (ohms) across the two bare terminals. For a 110V Silvia, you should get a reading of around 16 ohms. For a 220V Silvia, you should get a reading of around 64 ohms.
5. If your actual readings are much higher (or if you get an indication of OL), then your heating coil is probably broken internally. Off to the shop with your Silvia
Take $100 or more with you.
6. If your actual resistance readings are much lower, yet you are getting no heat, then there is something else going on that can't be diagnosed by these simple steps.
Finally, because a failing Silvia heating element can short to the boiler shell, I think it is a very good idea to plug your machine into an outlet protected by a ground fault detector (in the US, this is usually called a GFCI outlet). If the GFCI trips, then stop using the machine right away and take it to the repair shop for a new heating element/boiler top. Don't forget to take your $100+ with you.
Many other single boiler espresso machines are wired similarly. So this procedure will probably work on some other machines, too, but then again, it might not.
(This guide was first posted
here on CoffeeGeek and is cross-posted on HB with Dan's blessing).
Jim