Rocket Appartamento - sudden excessive overheating

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HedonisticBeans

#1: Post by HedonisticBeans »

I noticed since yesterday that the coffee temperature felt hot.

Today it began streaming and spurting.

I haven't changed anything. The machine is almost 2.5 years old. I make about an espresso a day.


JRising

#2: Post by JRising »

But that's after the machine has idled for a while and allowed the heat exchanger to heat up to boiler temperature, right? If you run a flush like that to let the super-heated water and steam out, it does return to running liquid water through the head and you can brew an espresso or several back to back after the flush, right?

HedonisticBeans (original poster)

#3: Post by HedonisticBeans (original poster) »

JRising wrote:But that's after the machine has idled for a while and allowed the heat exchanger to heat up to boiler temperature, right? If you run a flush like that to let the super-heated water and steam out, it does return to running liquid water through the head and you can brew an espresso or several back to back after the flush, right?
Not really after a while. About 3 hours.
Regardless.
It's never happened before.
It's never ever gotten this hot before.

HedonisticBeans (original poster)

#4: Post by HedonisticBeans (original poster) »

I removed the flow control device pressure gauge and installed the thermometer.

After 55m minutes from turning it on after it completely cooled down:

The machine was at 96 Celsius (205 f) and reached 102 Celsius(215 f).

My machine usually idles around 88 Celsius (199).

Farfetched, but could a flow control device cause over heating?

JRising

#5: Post by JRising »

"HedonisticBeans"
Farfetched, but could a flow control device cause over heating?
Not really, no. The flow control valve is completely out of the thermo-siphoning path.
I don't think your machine was overheating. It had just fully heated, properly. The boiler was fully heated and the heat exchanger was super-heated from being idle in the boiler as the machine sat un-used. It sounds perfectly normal, and if the cooling flush brought it out of idle and the machine returned to proper brewing temperatures, it seems fine.

HedonisticBeans (original poster)

#6: Post by HedonisticBeans (original poster) » replying to JRising »

I've owned the machine two years and 9 months.
It's always idled at 88-89 Celsius in summery and 89-91 in winter.

The temperature was 96 and reached 102 when running.

That's never happened before.
And I mentioned that it got that hot in 50 minutes from cold.

Nunas
Supporter ♡

#7: Post by Nunas »

Have you noticed any change in boiler pressure since this started happening?

HedonisticBeans (original poster)

#8: Post by HedonisticBeans (original poster) » replying to Nunas »

Yes

Boiler pressure is usually 1.1

It's now 1.3 to 1.4

Nunas
Supporter ♡

#9: Post by Nunas » replying to HedonisticBeans »

It could be that your pressurestat is failing, or become out of adjustment. The higher pressure results in higher boiler temperature, which would then transfer more heat to the HX. If it's an adjustable pressurestat (very likely), then you might be able to tweak it back into spec. Otherwise, it might need replacing. There are two ways they wire these. One is with heavy wire from the mains to the pressure stat then to the heater. If your machine is wired like this, then the only thing in that loop that might be loopy <grin> is the pressurestat. However, some are wired with lighter wire to the "controller box" inside which there's likely a relay, but sometimes there can be an external relay, usually solid state. If it's wired like this, then the pressurestat is still the most likely culprit, but not the only possibility.
Edit: I just looked it up online, Check this out https://support.clivecoffee.com/rocket- ... ssure-stat

HedonisticBeans (original poster)

#10: Post by HedonisticBeans (original poster) » replying to Nunas »

Thanks

Any experience on how a pressure Stat could come out of spec.?