La Marzocco 3 group vs 4 group - different steaming power?

[phaelon56]

Okay.... a Linea or FB70 three group has a 12.5 liter steam boiler and a four group has a 17 liter steam boiler. Does this allow the four group to steam faster or does it just allow quicker recovery time? We have two Linea three groups, one vintage 1995 and one from 1999. The owner is convinced that the 1999 machine steams a bit faster the the 1995 unit (probably because little if any proactive maintenance was ever done for gaskets, O-rings etc on these machines). The 19995 unit definitely needs a steam arm rebuild on one side but all on the staff seem to agree that the overall quality of the foamed milk is identical.

Enter the FB70. This is a four group that is brand new. Several people have commented that it produces better microfoam than the other machines.

Is this possible or is it subjective because they just enjoy the new machine and the ambiance of the new cafe so much? I never really did any steaming on the old machines and don't have the perspective to offer insight. Obviously a larger boiler has a larger volume of steam at the user's disposal but both the 12.5 and the 17 liter boilers are pressurized to 1.2 bars. So why the apparent difference? Could it be scaling inside of the old wands or is it really the larger boiler?

 

[CCafe]

Check the wattage on your elements. The 95 may have a lower wattage then the 99. If there both the same wattage, the other thing to do is use a multimeter and Ohm your elements.

To find what the wattage is, remember Ohm's Law Watts=(Volt*Volts)/Ohms. I don't know how big your elements are, but a 220volt 3000watt should come in around 16.1 Ohms. The higher resistance = lower wattage. Lower wattage increases recovery time.

Also try descaling the whole machine, inner boilers and all.

 

[CCafe]

One other thing. When checking for resistance make sure you disconnect the wires to the element. Other wise you'll get false readings. Remember to unplug the machine before you do any work! :shock:

 

[barefoot]

the four groups LM have THREE boilers not just two. We have afour group LM and there is one big boiler for the steam and TWO boilers for the group heads. You can set the temp differently for each pair of group heads. So two groups share one boiler. The result is better heat stability, faster recovery and better steaming results in my opinion.

 

[edna713]

What doe the nameplate say??

Does the 4 group need more power? 25 % more?? if not then the 3 group would have more steaming power -- Kilowatts divided by number of groups!

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