Hello fellow Home Barista's,

I've recently made the upgrade from a CC1 to a used Rocket Cellini V1. After receiving the machine I replaced the pump as it seemed to shut off when brew pressure ramped up.

With the new pump in, I fired it up yesterday and let it warm up for about an hour and began to prep my first shot with a cooling flush. During the cooling flush the green indicator light would flash once and the pump would turn off as seen in the video below.
The problem persisted so I proceeded to shut the machine off for a couple hours. The water I had been using was at 65 ppm, and after researching this issue a little, I figured maybe the water was too pure for the sensor at the bottom of the reservoir and replaced it with 145 ppm water.

I have not had the same issue since and was wondering if anyone can confirm the water was indeed too pure and caused that problem? Or if there might be another underlying cause?

Thank you!

WAG - Does this machine have a water level sensor in the reservoir? I do not think that the water in the boiler is the problem- I think it is the reservoir water level sensor having the problem. It loses it trigger (whatever that might be), and shuts down the machine for safety. The nature of the sensor will dictate the solution.

There is a pin looking part where the water reservoir sits on. I believe this is a sensor that detects whether there is water in the reservoir in which case there needs to be a certain amount of minerals in the water. I'm not sure if this is the case or not, but if it is, it appears 65 ppm water did not suffice and triggered the pump to turn off.

I was wondering if anyone else has had this issue with their Rocket when using water with that low of a ppm?

Valner wrote:I was wondering if anyone else has had this issue with their Rocket when using water with that low of a ppm?

Can't speak for the Rocket but as an FYI for proper operation and taste balance La Marzocco recommends between 90ppm and 150ppm.