How do you reset the thermostats on the rancilio?

Remove top panel and reset the thermostat on the boiler one of them tripped.

If you have reset the thermostats and still no heat then check for resistance on the elements they might be bad.

Remove the top panel, and check the thermostats on the boiler there are 3 of them. One needs to be reset.

Once you get the top off, there are 2 thermostats on the top of the boiler. Your looking for the thermostat that is on the front of the boiler with the red button . Push the red button. If that didn't work check the ohms reading on the element. It should read 12 - 16 ohms. If it doesn't replace the element. Also did you try to turn on the steam button? Sometimes the thermostat with the red dot on it goes bad. If it will steam just replace the brew thermostat.

If there is not a red pin on the top of the thermostats, then the easiest way to tell which one is bad is with an ohms meter or just replace both.

Remove the top panel one of the thermostats on the tank tripped, reset thermostat, and turn machine on.

Look for parts here
Rancilio Silvia Parts

If there is steam in the machine, the only other problem would be if the portafilter was cold and you are brewing into metal or glass demitasse that has not been heated.

I had the same problem, caused when I left it on all day and night. Just need to reset the safety thermostat switch. Check out the thread http://www.home-barista.com/espresso-machines/rancilio-silvia-powered-on-but-no-heat-t3630.html

Youve probably run your boiler dry and blown your thermostat/s. You'll need to have them replaced. You may get away with only having to replace one. It will cost about $80(AUS) to have done or less if you source the parts and do it yourself (not recommended).