|HOME||How to Order||
Why I use this particular PID unit (temperature controller)
Size: small size allows it to fit in small space.
Performance: the performance for this PID unit is excellent for espresso machines since you can achieve accuracy to ± 1 degree Fahrenheit ( 0.566 Celsius ). Overshoot or undershoot, if any, at any given time during a normal process, is minimal and also excellent for a small espresso machine like Silvia. More sophisticated PID units (like those made by OMRON or Watlow) can be programmed with computer software and will maintain an even more consistent temperature, but they are really more suitable for a food processing plant.
Simple: this PID unit is very simple to set up and to operate. You will not have to wade through 20 pages or more of instructions.
Cost: the cost is very low, which allows you to use your budget for system upgrades (using another of these PID units) such as: an additional digital thermometer for the brew head or for milk steaming. You can get all 3 PID units to control or monitor boiler, brew head and steam for the price of one OMRON unit.
Although I have never had one of these PID units fail, if you ever needed to replace a failed PID, it would be cheaper to replace this unit than the other more expensive units--like OMROM. All look-alike “Made in China” controllers such as the unit I use come from the same place, so you will always have a source for simple replacement in the unlikely event of a failure.
Remember, we are only working with a small espresso machine that is normally used to produce only 2 double shots of coffee in a session. Read this page.
What setup should I use?
A basic, low-cost setup includes one PID unit, one SSR (solid state relay) and a Thermocouple assembly.
A good first upgrade to the basic PID setup is a steam limit control which will replace the original mechanical steam thermostat. It is more accurate (narrow band) than the original mechanical thermostat and allows us to set lower limits than what Rancilio made on the steam thermostat.
Small on/off switch to disable the PID from controlling the boiler. It is useful for maintenance and every time when you don't want the boiler to heat up any more, like when you are done steaming and you just want to refill the boiler with fresh water.
A more robust setup adds a second PID controller to act as a thermometer to monitor the Grouphead temperature. It will give you a better indication than just guessing at when the boiler and Grouphead have reached proper temperatures for brewing (at cold start without this we normally just wait 45 minutes to allow the Grouphead to warm-up) You will also be able to monitor and see the variation in water temperature passing through the Grouphead just before the water gets to the puck. With this second PID unit (controller working as thermometer) you can add safety cut-off protection for the boiler and other features.
Manual Pre-infusion can be easily added to any setup.
Internal (pros and cons):
Internally installed units could be less expensive and are simpler to install (except for the cutting of the front cover of Silvia).
Internally installed PID destroys the original look of Silvia, but it can be reversed for less than$100 (the cost of a new stainless cover).
Internally installed PID is very beautiful and elegant, which you can see here the internal install, but there is a space installation issue and a big "However".
With an internal installation, you will have to plan PID location carefully because space is limited on the front panel. The extreme heat from the boiler could shorten the life of the controller, although they are relatively inexpensive to replace.
This is the “However”: The space inside Silvia for the various instruments is very limited and filled not only with wires and water lines, but also the Silvia brass boiler. When the machine is used to brew and then to steam—and then is used to brew again (even though you should not do this with Silvia), the high temperature fluctuation affects the accuracy of the PIDs which are within the machine and they may stop functioning. But yes, after cooling down, the controller will become accurate again.
The effect can be reduced by insulating the boiler and other parts of the machine and by insulating the PIDs. There may still be some small inaccuracy, which can be annoying to a Silvia user who has customized the machine to assure zero accuracy.
Therefore, I do not recommend an internal installation without insulation.
If you still want to try the internal install, then insulate the boiler and if you are a heavy user or just want to give a better life to the controller, plan on insulating the controllers too. You can find more information here on the internal install,
External (pros and cons):
In an external install, the PID unit is away from the extreme heat environment; therefore it will not become dysfunctional at any time and it is more suitable for high usage of the machine, without facing the internal technical challenge. (not like internal kits, external kits can be purchased as plug and play kits).
The PID Units are angled and so are easier to read.
An external PID provides an external on/off switch (which would have to be a separately installed option on an internal PID) that allows you to bypass the PID when cooling the boiler after steaming or when cleaning the machine.
External install may not be as exquisite and beautiful to some, but it preserves the original look of Silvia, is practical, is more accurate in operation and is more durable.
How PID control works with Silvia. & Full Set-up.