Linea 1 group brew boiler recovery

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NickA
Posts: 184
Joined: 16 years ago

#1: Post by NickA »

I'm just starting to do tests on my Lineastein 1EE. It seems that if I draw say about a cup of water from the brew boiler, the temperature starts dropping from say 94 degrees C to 92 degrees. If I keep on drawing water, it will keep on dropping; I noticed when I was wanting to purge water from the boiler and was just pouring into the drip tray; with several cups worth it had gone down to 88 degrees. It will then take maybe 25-40 seconds to get back up to temperature. Is this just the result of having a 1000 watt heater? I'm used the the 2AV were I didn't even notice a temperature drop; it may well have been there but it certainly wasn't obvious.

Anyone else with a 1 group Linea that could comment?

Paolo
Posts: 550
Joined: 17 years ago

#2: Post by Paolo »

Hi Nick,
When I drop a cup from the brew boiler as you have done, the boiler temp. drops from the pre-set by less than 1 degree C. If I drop more water out than a cup, the temp. will indeed go down accordingly as room temp. water is drawn into the boiler to replace the hot water being delivered at the group.

IMO 25-40 seconds is nothing in the scheme of things. Keep in mind that a normal shot is around 25ml....nowhere near the 200ml in a cup.

(The PID readout on my EE during a shot fluctuates by around 0.2C.)

The measure of the heating potential to me is the heat-up time from ambient temp. In my EE it is less than 10 minutes, which is slighly more than what my 2 litre kettle takes to boil a full load.

P.S. Love what you did with your Lineastein!

NickA (original poster)
Posts: 184
Joined: 16 years ago

#3: Post by NickA (original poster) »

Hi Paolo, thanks for that, that sets my mind at ease. I've just pulled some pretty drinkable shots, so I'm happy with how the machine is shaping up. I'll put up some more pictures soon of the (almost) finished result.

gscace
Posts: 752
Joined: 19 years ago

#4: Post by gscace »

NickA wrote:I'm just starting to do tests on my Lineastein 1EE. It seems that if I draw say about a cup of water from the brew boiler, the temperature starts dropping from say 94 degrees C to 92 degrees. If I keep on drawing water, it will keep on dropping; I noticed when I was wanting to purge water from the boiler and was just pouring into the drip tray; with several cups worth it had gone down to 88 degrees. It will then take maybe 25-40 seconds to get back up to temperature. Is this just the result of having a 1000 watt heater? I'm used the the 2AV were I didn't even notice a temperature drop; it may well have been there but it certainly wasn't obvious.

Anyone else with a 1 group Linea that could comment?
Hey there:

Dunno if that's normal for the 1-group or not as I have a 2-group, which has a much bigger heater in it. the fact that you experience temperature drop is the motivation for installing feedwater preheat systems. such systems usually preheat the water entering the brew boiler by passing it through a "heat exchanger" in the steam boiler that is big enough to raise the water temp somewhere near that of the brew boiler. As I recall, Paul Pratt developed a preheat scheme that could be retrofitted into Linea steam boilers without too much trouble. Dunno if he has them for sale, but he might. Also, Bill Crossland told me a clever way to add feedwater preheat is to install a small point of use water heater (set to around 200F) between the rotary pump and the water distribution block at the machine's water inlet. the water heater apparently fixes the condition that you describe to a very large degree and doesn't require alternative internal plumbing schemes.

For two-groups, I tune the PID controllers so that they are very fast responding. It's ok for the PID controller to be over-reactive and overshoot a bit as the water in the group neck attenuates overshoot. You can't see the overshoot with a Scace device, so tune for aggressive response to temperature drops.

-Greg