This topic is split from the Profitec Pro 800 Lever w/PID which started to veer from the Profitec Pro 800 into dipper levers in general. To preserve continuity in the original thread I am going to copy the original messages to start the split here:
BartG wrote:Thanks for the link! This is an interesting overview.
I wonder how temp stable the grouphead is, and how long it would take to warm up.
A comparison with the Strega and Londinium would also be nice
JohnB. wrote:Since it's a dipper & uses the same basic group I'd imagine that it's pretty similar to my Bosco Sorrento. The group isn't fully up to temp until the upper end of the lever handle is pretty much too hot to hold. This takes between 1-1.5 hours. Boiler is up to temp much sooner but your shot water will be much cooler then when the group is fully heated.
The group will lose some heat while idle. If it behaves the same as my Sorrento once fully up to temp a shot with no flush would get you a peak brew temp of 198°F, a 2 second flush before that shot would get you a peak brew temp of 201°F. This assumes a p'stat setting in the 1.2-1.25 bar range & a room temp in the mid 70'sF.
samuellaw178 wrote:From looking at the video, I'm quite sure there's no special reservoir like a Bosco. The boiler neck looks similar to my Brugnetti Aurora - which is just a brass/copper neck brazed onto the copper boiler. I imagine there's a tube that draws water from the boiler, and that tube connects directly to the group head (most dipper config group head already has an existing threaded hole at the back for attaching tube, it doesn't make sense not to use it).
The heat up time is almost certainly around 45 min -1 hour, not 1.5 hour because the group is connected directly to the boiler (and maybe the neck area is steam saturated too to help warm up, but that's just a wild guess), with just a gasket sandwiched in between. This gasket design (material & thickness) will be the key to determine if the machine overheats - it doesn't appear so.
This is how Brugnetti Aurora's boiler looks like (credit to Andyone posted in https://www.kaffee-netz.de/threads/rest ... tti.20634/)
It even has the casted port on the neck, but not tapped/drilled:
This is my guess how it looks like :
samuellaw178 wrote:The heat up time is almost certainly around 45 min -1 hour, not 1.5 hour because the group is connected directly to the boiler (and maybe the neck area is steam saturated too to help warm up, but that's just a wild guess), with just a gasket sandwiched in between. This gasket design (material & thickness) will be the key to determine if the machine overheats - it doesn't appear so.
Obviously the Bosco group is connected directly to the boiler also & temp testing with a Scace device has shown that the 1-1.5 hour figure for the group to reach max idle temp I quoted is accurate for the Sorrento. I'm sure that boiler size plays into this so the 800 may heat up faster with its smaller boiler. No idea & remember I'm talking about max idle temp. The group will certainly be hot before this time but you won't get the same brew/shot water temps without flushing more water through the group if you pull shots prior to the group reaching max idle temp.