Rocket Giotto not filling from reservoir

#1: Post by Hc » June 5th, 2021, 5:32 am

Hi,

I've had my Rocket Giotto plumbed in for the last year; I've not had the reservoir in place in that time. I am trying to descale it now by flipping the water source switch from the water line to the reservoir, replacing the reservoir and filling it with descaling solution. But I've run into the problem where the machine is not taking up water/solution from the reservoir. I've tried flipping the switch a few times, turning off the water supply, and removing and replacing the reservoir a few times.

Any suggestions are most welcome.

#2: Post by **BaristaBoy E61** » June 5th, 2021, 9:09 am

Is there an additional switch for a Reservoir 'Low Water' Alarm as well?

June 5th, 2021, 10:34 am

Thanks for that suggestion, but I have a likely candidate. I took the cover off the machine, and checked the solenoid voltages. Depending in the water source switch, either of the two solenoids was getting 230 V. Then I disconnected the pump and listed more closely, and I noticed that when the brew lever is engaged, the water intake solenoid for the water line is clicking quite loudly. The one for the reservoir does not click, so I think that's what's broken in some way. I've made sure it's connected properly.

Is it viable to try and clean it or should it be replaced?

#4: Post by **BaristaBoy E61** » June 5th, 2021, 11:51 am

You can try to take apart and clean the defective solenoid but first you can also pull 1-wire from each solenoid and with the power 'OFF' and unplugged, measure the resistance of the solenoid 'Coil' if you own a meter and feel competent to perform this test. That is if the solenoids are the same part number. They should measure the same resistance within a few Ohms.

The Coil Resistance might even be printed on the Coil Specs on the electronic part of the solenoid's coil.

June 5th, 2021, 12:17 pm

Thanks, I had already gone ahead and taken apart the valve assembly. One solenoid valve was in fact stuck closed while the other moved freely. There were mineral deposits in the valves, so I'm cleaning them now and will report back when it's back together.

#6: Post by Hc (original poster) » June 5th, 2021, 2:25 pm

The repair was successful. So in short (in addition to the resistance/voltage check above):

0. Remove the top, back, and then side covers. If necessary also remove water reservoir and reservoir, or loosen any components that are in the way.

1a. To verify the problem is one of the solenoids, disconnect pump and put the brew lever in the brew position. The solenoid corresponding to the water source selected should now audibly 'click', without the pump running. If the water line is selected, water should also leave the group head at line pressure. Do not confuse the relay 'click' (from the relay next to the valve assembly) with the solenoid 'click'.

1b. Now switch water sources using the switch, and check the other solenoid valve. If one clicks but the other one doesn't, you'll need to take it out and take it apart.

2. To do this, remove the brass tubing connections and the 'chassis bolt'. Also remove the plastic tube coming from the water reservoir. Then loosen the bolt on top of the solenoid and remove solenoid coil housings. These should not be too tight. Then unscrew the metal tube from the valve. This is on there pretty tight (15-25 Nm?). I put the whole thing in a bench vise.

3. In my case, I could see and feel that the spring and 'actuator' were stuck inside the metal tube, and I loosened it with a screw driver. It just comes out. There were also a few small bits of scale in there.

4. Clean everything, put back together in reverse order, and happy brewing. Oh, and be sure to check for leaks before you put the cover back on.

Other resources:
https://brooks-parts.com/en/blog/espres ... -valves-n5
http://www.espresso-restorations.com/solenoids.html