John, the cold line runs to the bottom of the HX where the thermosyphon tube coming from the bottom of the Group enters the HX lower rear of boiler.

The main water feed for the boiler enters the end of the boiler and only lets water in when the water level sensor demands it. The first water point in the machine is the Tee where manual fill valve is located and the cold water out to the HX goes. The other leg of the Tee goes to the solenoid fill valve and into the end of the boiler where the manual fill valve dumps water.







When the Lever / Thermosyphon HX is demanding water it happens directly from the water main line in.

Got it. Took a look at the hydraulic schematic for the Mirage Idrocompresso as it's a cold fed HX lever also. Works the same except Kees installed either fixed jets or an adjustable valve to control flow/shot water temp.

From the Idro Owner's Manual:
"The entire system allows for very stable water temperature at the coffee bed with low and high brewing volumes in combination with high steam pressure. The water at the coffee bed can be adjusted to as low as 88 °C by altering the flow restrictor (either by changing the fixed-opening restrictors or by regulating the adjustable restrictors)."

I would think that you will need to install a valve to regulate the flow if you want to accurately control your shot water temp range.

John, so you think the water needs to sit in the HX longer to lower the temps?

Great info and great pics and videos - Thanks!

FotonDrv wrote:John, so you think the water needs to sit in the HX longer to lower the temps?

No, my thought was that by adding an adjustable valve you would be able to regulate the flow through your thermosyphon. If you reduced the flow through the group it would run cooler & pull more heat from your shot water resulting in a lower shot temp at a normal p'stat setting.

I see now, you are trying to lower the overall temperature of the Group at idle by restricting the flow through it.

I ran across this in another Thread about Lever machines and their temps.

FotonDrv wrote:I see now, you are trying to lower the overall temperature of the Group at idle by restricting the flow through it.

I ran across this in another Thread about Lever machines and their temps.


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Yeah, that's the one I mentioned earlier in this thread that Vlad shared the link to. It's also the same one where he found that, for the Lambro at least it's beatty to leave it running slightly got and then lock in a cold portafilter during shot prep to drop the temp a few degrees of desired. I follow pretty much that same advice until I decided to modify the termosiphon on one of my groups to run a bit cooler. The problem now is that it runs a little too cool during the winter, so I may wind up removing the restricter or installing an adjustable one.

Thanks for the input Dominick.

Could someone Post the specs/dimensions of that rotating rod that sits in the plug behind the Group?? Do you think it would just screw into the Group used on the Londinium machine?

JohnB. wrote:Can't you guys play with the thermosyphon flow to cool down the group? You shouldn't have to drop the boiler pressure to .8bar on a modern spring lever to achieve normal shot temps. If there is no flow adjustment I'd add an adjustable needle valve so you could regulate the flow through the thermosyphon.

Here is a photo of a needle valve in the hot leg of the thermosyphon on my Salvatore Compact Lever. I can run hotter boiler temps for good steaming and reduce the flow in the thermosyphon to keep the group from over heating.



After a shot, recovery times are slowed a bit, but I am not generally pulling back-to-back shots.

Did that needle valve come on the Salvatore? If not, what/where can I find that part?

Is that insulation OEM Salvatore?