Weird pressure cycling on Rocket R58

axpetts

Hello all.

Have been having some weird pressure cycling on my plumbed-in Rocket R58 today. Seems to come and go and I was wondering if anyone else has seen similar and knows if either a cause or fix.

After a shot is pulled or pump is activated, the brew boiler pressure seems to go up to 15 bar and then settle back down to line pressure (3 bar). During the shot the brew boiler pressure stays at 9 bar. This is in the first video. Then the brew boiler pressure seems to cycle between 11 bar and line pressure. This looks like it might be in coincidence with when the brew boiler drops 1 degree below target temp (and possibly when the heater kicks in). This is shown in video 2.

There’s no obvious leaks and it doesn’t seem to be impacting shots so I’m not overly concerned. Would like to understand what’s going on though.

Cheers, Andrew

Video 1 - pressure cycle after pump activation

Video 2 - pressure cycling at rest

DavecUK

axpetts

A few questions:

Age of machine
Have you had it from new, if not how long have you had it
When was it plumbed in and is there a pressure regulator
Did this ever happen before, or did it just start today
did this change in behaviour occur after any significant event, descaling, plumbing in etc..?

then I can give you a proper answer.

axpetts

I’ve had it from new and it’s around 12 years old. It’s been plumbed in for probably 10 years or more and there’s a pressure regulator on it in line with a softener/filter system. The plumb line all looks good - no fluctuations in pressure there. It’s happened a few times before and gone away. Nothing significant happened today that would have triggered it. Pulled my morning shot as normal and it started. Yesterday no such issue. In the past it has gone away on its own - I expect it will do the same again. Just curious as to what could cause it.

I think the OPV safety valve in the Rocket lifts around 14 bar so I suspect it has something to do with that. Possibly some trapped fluid which is heating/expanding in the line causing that to lift, maybe.

axpetts

Just observed that the fluctuations stopped after I did a back flush. They started again after I lifted the lever and activated the pump. Odd

giampiero

I don’t know the hydraulic system of the R58, but if you can eventually touch the inlet pipe in the closest point with the machine and feel if is at sensible higher room temp.

I says that because if the brew boiler check valve is leaking back, it could be the cause of the increasing pressure you read in the gauge.

axpetts

giampiero I don’t know the hydraulic system of the R58, but if you can eventually touch the inlet pipe in the closest point with the machine and feel if is at sensible higher room temp.

I says that because if the brew boiler check valve is leaking back, it could be the cause of the increasing pressure you read in the gauge.

Do you mean the inlet to the brew boiler? If the check valve was leaking or passing I would have thought that would present as the brew pressure struggling to reach target, not overpressure. Because the check valve vents to drain there is no back pressure to speak of and therefore no additional pressure to put into the boiler.

giampiero

axpetts English is not my native language, so i always called “check valve” a valve that does allow the water flow only in one direction, if i say “non return” valve probably is more clear.

Anyway, i’m sure that some guy with direct experience with this specific model will chime in to offer you better advices.