Rocket Appartamento very slow heat up

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#1: Post by AHaddock »

I have a very weird problem with my Rocket Appartamento. I've searched previous topics but didn't find an answer. I hope somebody can give me some tips.
The machine is 4 years old, not plumbed in, and it has always worked perfectly. It takes about 15-20 min. to heat up. Two days ago this changed, after 30 min. the group head was still warm-ish, enough to touch it with your hand (which I definitely could not do before). Now it takes about 1 hour to heat up enough. Even so, the quality of the shots is not as before. Thre pressure, however, was fine: the needle was right in the middle of the green zone. I've seen some videos about resetting the high limit switch. Would that help?
I'm frateful for any suggestions.

UPDATE: A solution was found. Check the end of the thread.


#2: Post by NicoNYC »

Doesn't sound like a limit switch if the pressure gauge reads fine. It reads off pressure much like your boiler gauge so it would only be an issue if the pressure was wrong. People adjust the switch to fine tune the boiler temp but it sounds like you're beyond fine tuning.

My first guess would be an issue with the thermosyphon.

Water forms a convection loop in the heat exchanger and E-61 head; as water is heated in the HX, it rises, flows through the head heating it, and returns to the bottom of the HX to be heated again. Scale in the pipes, grouphead, or at the restrictor plate could slow or stop this, though you'd probably notice a reduced flow when pulling shots. Also read this about air trapped in the thermosyphon:

Alternatively, perhaps your vacuum breaker is clogged. Next time you start it up, leave the steam wand valve open for 10 min then close - purging the air from the boiler like the vacuum breaker would. You can also start the machine up with the cover off and watch the vacuum breaker (looks like this: ... ker-valve/). It should let out air, then a sputter of light steam, then the pin should raise and it won't let out anything. Usually they stick open and leak, but it could stick shut. Some can be disassembled, descaled, and rebuilt, or you can replace it, it's a $20 part.

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#3: Post by erik82 »

First idea would be a thermosyphon stall. When you flush water through the group after 20min does water come out right away or steam first? If it's the latter then it's definitely a thermosyphon stall. If it heats up normal after a short flush then the conclusion would be the same. This is the easiest test you can do.

AHaddock (original poster)

#4: Post by AHaddock (original poster) »

Thanks to erik82 and NikoNYC!
I'll try your suggestions with the wand and the short flush. Tomorrow, though... too late for coffee now :)

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#5: Post by Bluenoser » replying to AHaddock »

A 15 second flush should be able to clear out air in a stall. After 4 years cold be scale. I'd remove the mushroom to look for scale and I'd remove the TS pipe with the restrictor. That could be partially plugged.

AHaddock (original poster)

#6: Post by AHaddock (original poster) »

Thanks for the suggestion Bluenoser.

Update. I tried the suggestions of erik82 and NikoNYC.
Leaving the wand open 10 min during warming up didn't seem to have any effect. After 30 min. the group was warm, but still touchable.
A short flush at that moment produced water right away, no steam first.
After 30 min. the top part of the machine, sides and cup rest, were very hot, as they used to be, but the group wasn only very warm. I flushed some water through the water wand and, after that, the group did got properly hot.
Clearly the boiler is getting the right temperature, but the heat is not reaching the group head. I suppose it means clogging, like Blunoser suggests. I didn't want to open the thing but it seems I'm going to have to.
I'll keep you posted, in case anyone is interested.


#7: Post by erik82 »

This might help Great site from a fellow HB-er.

Did you do a descale of the machine ( That might also solve the issue without opening the machine up if you're not comfortable with that.

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#8: Post by Bluenoser »

A machine descale might remove scale bits but they can flow and block other places. Some vendors dont recommend descaling for that reason. It is safer to see if u can remove the mushroom and TS pipe first and descale those individually. There are good vids on that and if you are going to own an E61 machine you are going to have to learn these tasks at some point. I was reluctant to disassemble at first. Im comfortable with it now.

AHaddock (original poster)

#9: Post by AHaddock (original poster) »

Thanks again to you all for your continued interest.
To answer previous suggestions: I've never descaled the machine, because the manufacturer does not recommend it. Apparently the chemicals could be harmful to internal components and also difficult to remove completely afterwards.
I took out the mushroom, see attached some images of it, the spring, the valve and the interior of the chamber. It's the first time I've done it so I can't say how much scale is that. The gaskets seemed in good condition.
Anyway, I cleaned everything as best I could, put all back together, switched on the machine and... the problem is still there. After some 30 min. the sides and top of the machine are very hot but the group is not. If I do a short flush, either through the group or the water band, then the group starts to heat up and gets properly hot after some more minutes. It seems the hot water is not entering the group unless I do a flush. Before all this started I didn't need to do that.


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#10: Post by Bluenoser »

I'd say its pretty clean.. it doesn't look like you have copper corrosion.. You've got some particles in there and I have no idea what they'd be. People with more experience might chime in.. Looks like a ceramic coating on the mushroom.. I've never seen pictures of a white one before.. But if you are getting those particles.. there is a good chance that some of that cruft might have gotten stuck in the 3mm hole (restrictor) in the top thermosiphon tube.. (I assume it is in the top pipe.. that is where mine is in my Profitec).. So that pipe on mine is pretty easy to remove. I used a small drill bit to ream and clean out mine. Check that there are no leaks in the thermosiphon section that air is getting in.. Pretty simple system in theory.. water circulates and heats the group by convection.. so maybe the restrictor has closed off a bit.. or somehow you are getting air in there and it is locking the thermosiphon so it can't flow.

I got some descale solution and soaked my mushroom and the top tube for about 20 minutes.. Since you have some particle buildup, look for that at the ends of the pipes.. If you remove both pipes, just check around the openings to look for buildup.

I use Dow Corning molykote around all the O-Rings when I reassemble.

I'm not a very experienced or knowledgeable troubleshooter of espresso machines.. but I do have an HX.. so there could be flaws in my reasoning.