Help Please: Servicing an HX Rocket espresso machine. How can I include a video ??

[rogher]

I think something's blocked in my Rocket espresso machine.
It screeches and dumps water when brewing, so shots are taking longer.
The screech is the same as I get when back-flushing.
De-scaling does not seem to help.
My machine is plumbed-in using filtered water.
No-one in the UK seems interested in servicing, so a home repair is required unless I use it as an excuse to upgrade (but even that is difficult in a lock-down).
So where should I start?
Any help most gratefully accepted.

 

[Musicphan]

Post a video first... hard to diagnose without hearing/seeing it...

 

[rogher]

Thanks.
I'll do my best - that's something I've not done before...
please be patient!

 

[rogher]

how do I attach a .mov file from my computer?

 

[Musicphan]

You may not have enough posts to be able to do that.. upload it to youtube or vimeo and then post the link

 

[rogher]

how's that?

With a blanking dish inserted in the portafilter for backflush, the group head pressure rises from around 9 bar to 13 bar (in case that's significant).

 

[Musicphan]

I spoke to a friend who is the local espresso machine tech... feedback:

"That is a relief valve screaming, I would start by checking the pump pressure, it sounds like it is WAY too high blowing water out of the relief valve that is set to release at 12 bar. 9 bar is pump max. If not that, the relief valve needs to be tightened down".

 

[rogher]

I'd agree with that logic.
So how do I adjust the pump pressure?
There is an adjustment for the relief valve under the machine, but I'm not aware of any means to change pump pressure...

 

[Musicphan]

You don't mention themodel you are using - does it have a pressure gauge on it? What is it reading before and when pulling shot?

 

[rogher]

Group head pressure goes to 12.5 bar.
I've tried reducing the pump pressure by releasing the nut on the bottom of my Rocket machine by six turns, but there was no change.

 

[CafeLast]

Where are you located? Here is a list of espresso installers/technicians if you can't figure it out yourself. You might need a professional.

 

[rogher]

Where are you located? Here is a list of espresso installers/technicians if you can't figure it out yourself. You might need a professional.

I'm in the West Midlands, UK.