Hot water in reservoir for better thermal stability?

#1: Post by **Emoto** » June 8th, 2009, 1:33 pm

Ok, here's a whacky idea. Feel free to tell me I'm nuts.

Has anyone ever experimented with putting hot water in their machine's reservoir? On a machine such as a Silvia, wouldn't this help maintain thermal stability a little bit when pulling shots? Just wondering...

#2: Post by **another_jim** » June 8th, 2009, 1:59 pm

When Mark Prince reviewed espresso machines, he used to ding the ones that overheated their reservoirs. The justification is that espresso pumps are typically spec'ed up to 105F (40C).

However, the pumps don't seem to be worse for wear sitting inside 140F (60C) espresso machines; and the hotter the water coming into the boilers or heat exchangers, the easier it is to create a temperature stable design, and the more energy efficient the machine.

#3: Post by HB » June 8th, 2009, 9:37 pm

Emoto wrote:On a machine such as a Silvia, wouldn't this help maintain thermal stability...

I wouldn't want to heat the reservoir water since it will get slimy faster. A coil of copper tubing wrapped around the boiler to preheat the incoming water would be easier. Google a bit, you'll find other threads suggesting the same idea.