I searched for this topic and didn't find what I needed:

Looking to buy my first HX machine. PID controlled is more $$ than non-PID HX machine.

Here's my question, asked different ways: Does the Eric E61 thermometer make the PID unnecessary? Is the PID better? Does it make more sense to pay the extra $ and buy the PID over installing the eric thermo?

PID is not that important on an HX, since it manages the temperature in the steam boiler, and precise temperature control in the steam boiler has little advantage in controlling final brew temp. A good pstat will effectively do the same job.

The final brew temperature is a result of the steam boiler temp, the group head temp, and your flush routine. Having Eric's thermometer will be a much more useful tool for managing your brew temperature.

+1 what Dan said. boilers follow the STP (standard temperature pressure) rule. One is directly related to the other. If pressure goes up, temperature goes up commensurately. Or, if you increase temperature, the pressure will rise. That is in a closed system, which is what we have until we open a valve, the OPV (over pressure valve) opens, etcetera. Pressure stats are mechanical contrivances and have a broad neutral band. PIDs are electronic and their neutral band is adjustable. None of this matters much in an HX, because you are not using the boiler water to make coffee. Inside the boiler, there is a heat exchanger (simple copper tube) through which the water from the reservoir passes on its way to the group head. As it passes (or just sits there), it heats. If it just sits there, it goes beyond boiling, which is why we give the HX a little flush before pulling the shot. We need to get the temperature of the water down to just below boiling (most people shoot for about 90-degrees C). As the price of PIDs has dropped, the difference between fitting a PID and a pressurestat has become smaller. I suppose that one day pressurestats will go the way of the dodo bird and all the machines will have PIDs, just like is happening with electric kettles. However, it won't make one iota of difference in the cup. Unless you have a really top end machine that does blended hot/source water, you'll still have to do the 'water dance' flush.

The only thing the PID does on a HX is be more quiet and make it easier to adjust *steam* boiler temperature.
It will not make it better at controller brew temperature.

So, will a pid allow for quick and easy adjustment say for allowing boiler to achieve higher temp for steaming milk after a shot is pulled?
I've found my shots taste best at a temp less than ideal for fast steaming of milk. If there were a way to adjust this without having to turn the p-stat screw, that could be handy.

That's a bit of clunky way to use a HX machine and sort of defeats the purpose. Better to set for adequate steam and then tweak your brew temp via flush routine.

johneverett wrote:So, will a pid allow for quick and easy adjustment say for allowing boiler to achieve higher temp for steaming milk after a shot is pulled?
I've found my shots taste best at a temp less than ideal for fast steaming of milk. If there were a way to adjust this without having to turn the p-stat screw, that could be handy.

See what h3 wrote.
What is easier is adjusting the temperature the few times you do it. You wouldn't really do it after a shot.

To adjust the brew temperature, you use a longer or shorter flush before pulling your shot.

Thanks for your help with this.

If you had to choose between a PID *OR* a Eric Thermo, which would be more helpful at making better espresso?

TheHainster wrote:If you had to choose between a PID *OR* a Eric Thermo, which would be more helpful at making better espresso?

In short, Eric's thermometer.

Whether you use a pressurestat or a PID on an HX machine, you are going to arrive at the desired brew temperature by flushing, and if you want to know the brew temperature precisely, you need Eric's thermometer.

Rocky

RockyIII wrote:In short, Eric's thermometer.

...and if you want to know the brew temperature precisely, you need Eric's thermometer.

Great summary. Understood. Thanks