Rocket Appartamento not building steam pressure

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
caddyquack

#1: Post by caddyquack »

One morning I arrived at my machine and it was warm but had no steam pressure (I have it on a wifi outlet on a schedule). Water flows through the portafilter at what seems like regular temperature but the steam gauge shows 0 and nothing comes out of the steam wand or hot water dispenser. I turned the machine off, let it cool down, and started it again while watching its behavior. Here is what I observed.
  1. Early startup seemed normal, it made familiar noises and began heating up to the point where you could feel a little heat coming out the top.
  2. The machine started releasing steam out of the top. I could hear and feel the steam. This also seems normal to me.
  3. After about 5-10 seconds, a valve closed and it seemed like the steam was beginning to be trapped in the system. This also seems normal to me.
  4. However, after about 10s, before the pressure gauge moved at all, I hear a little puff like the steam is being released. This does not seem normal.
  5. The machine never starts making steam again unless I turn it off, let it cool, and restart the cycle. Then the process repeats.

After this, the machine stays warm, it just doesn't build any steam pressure.

I surveyed other similar posts here but couldn't find one matching my exact symptoms. There were many similar threads and from those I've gotten the idea that there is something wrong with my pstat or controller. However, given my lack of knowledge in this area, I'm not sure how to proceed with identifying which one is broken or if it's something entirely different. I'll document what I've checked so far.

I opened up the machine and identified the pstat and controller. Nothing is visibly wrong. Everything looks clean and nothing looks burnt. With a multimeter, I tested the resistance at both ends of the wires going from the pstat to the controller. They both read 0.3 ohms. I'm not super familiar with electrical currents so not sure if this is helpful or what it is supposed to read but at least this should mean the circuit is not broken I think.

Appreciate any help in further troubleshooting. My machine is about 5 years old and this is the first issue it has had. I do tend to leave the machine on and idle more often than necessary as I get distracted waiting to make my coffee so maybe being on a lot has something to do with it. Thanks in advance!

JRising
Team HB

#2: Post by JRising »

So you've read the threads about the 2 different types of pressostats and the 2 different ways a North American Appartamento might be wired. Can you confirm which yours is? This does narrow down the odds of it being the pressostat, element or powerboard.

Rocket Appartamento not maintaining steam pressure

This thread goes through the symptoms of determining that the powerboard is at fault in one of the appartamentos that came from factory wired to protect its pressostat but use the powerboard's own relay for switching the load. If your pressostat is like that with the skinny wired only to the powerboard this is most likely your issue.
The thread concludes, I believe, with the rewiring for a better future but replacing the expensive powerboard.

caddyquack (original poster)

#3: Post by caddyquack (original poster) »

Thanks for the response! Not sure I've read about the two different types of pressostats but have read the article linked below here it disucsses the types of wiring. Mine is the same as the one in that thread where both the black and white wire go from the pressostat to the powerboard directly.

I just wasn't sure my issues was necessarily the same since the behavior of their machine was different. It would pressurize initially but then fail to re-pressurize. Do you think there is any chance it is the pressostat over the powerboard? Any test you know I could do to rule one out over the other?

caddyquack (original poster)

#4: Post by caddyquack (original poster) »

I've been digging through the threads more and trying to understand how these components work together so I can understand why and what isn't working. My machine has also been working less lately to the point where now it barely turns on or stops heating quite early, after maybe 10s. I found the thread below which had a great writeup from JRising about how to test the machine while on with a multimeter.

Rocket Appartamento not heating

I tested the voltage from P to N and could see 120V. I also hear the click when the machine turns on and tested from Resist. to N. Here I see that when the machine is heating up, I see 120V, then it tends to drop to 0 or near 0 and that is when I hear it stop heating up. Seems fairly certain from this that it is the control board. Only thing I don't understand is that I also see 120 V from P to Resist (positive on P, ground on Resist). I'm not very knowledgeable about electricity but am curious as to why this would be the case.

Anyways, going to order a new control board as it seems fairly certain at this point that is the cause. Will update once it arrives and is installed.

JRising
Team HB

#5: Post by JRising »

caddyquack wrote:I found the thread below which had a great writeup from JRising about how to test the machine while on with a multimeter.

I tested the voltage from P to N and could see 120V. I also hear the click when the machine turns on and tested from Resist. to N. Here I see that when the machine is heating up, I see 120V, then it tends to drop to 0 or near 0 and that is when I hear it stop heating up. Seems fairly certain from this that it is the control board. Only thing I don't understand is that I also see 120 V from P to Resist (positive on P, ground on Resist). I'm not very knowledgeable about electricity but am curious as to why this would be the case.

Anyways, going to order a new control board as it seems fairly certain at this point that is the cause. Will update once it arrives and is installed.
I concur that the Resistenza relay on your board is failing when warm from what you've said.


This may explain the voltage test... The blue side of the element is ALWAYS connected to neutral. Only when the Resistenza Relay is closed (on) is the black side of the element connected to phase... So you'll always get 120VAC from phase to the blue side of everything, but from the black side of a component to any blue is live only when that component should be on.

caddyquack (original poster)

#6: Post by caddyquack (original poster) »

Thanks for the confirmation JRising. I want to take the opportunity to improve upon the wiring as discussed in the other linked thread so that the pressostat goes in the future instead of the new control board. I am pretty sure my pressostat is only rated for 0.1 A so I will need to replace. Can you confirm I am reading this correctly? Also, instead of cutting the wire, do you know what kind of wire the thicker one is? I would prefer adding a new wire so I can re-wire back to factory configuration later on if needed. Thanks!


JRising
Team HB

#7: Post by JRising »

You are correct. You'll want to put in a 16A Ma-Ter pressostat along with high temperature 14 gauge wires. (I imagine Rocket is using 16 gauge, but 14 will conduct more heat away from the terminals, so I suggest it. The price difference is more than worth it. You could go so far as to begin replacing all wiring in the element circuit with 14 gauge.

caddyquack (original poster)

#8: Post by caddyquack (original poster) »

As expected, replacing the control board fixed the machine. I then replaced the pressostat and the wiring and everything is working great. Hopefully I don't have to replace the control board again now. Thanks for the help JRising!