I am restoring a Pavoni Pub S. Actually, it only needed some minor cleaning to get it running. But this morning I noticed that when the machine is fully heated, the pump periodically kicks on with a bit more noise than normal. Its very quick on and off again. Is that normal with this machine?

Also, while pulling a shot, the was a sudden loud screech (like when the fan belt on your car is loose). I am not sure what the noise was, but was able to make it go away then pull the shot.

Does anyone have input for me on these two issues?

My Pub doesn't do that. Have you checked the auto-fill probe? Make sure it's clean and connected properly. Mine has a blue wire for that task. And is your machine plumbed in directly? If so what does your line pressure read? The pump should be nice and quiet; it may be screeching from lack of water supply. I'm running my Pub off a bottle and it draws nicely without the help of a flojet, but when it was at my house and connected if the line pressure was too low it would squeal a bit. Oh, and what size tubing is feeding the pump inlet?

I think it's a 3/8 ID tube on the water line. The pressure gauge usually reads about 5 bar. But I am not so confident on that. Is it possible that the pressure way too high? The sound seemed to come from the group.

Also, can you fill me in on the auto fill valve? Does this fill the boiler? I thought I manually fill the boiler.

Again. This machine is new to me. Thanks for your help.

Oh, if the screech is in the grouphead then there must be an obstruction. Have you run any descaler through the heat exchanger?
If your line pressure is 5 bar while idle, where does it go while brewing? It is possible that the pressure can drop dramatically while running the pump.
Where is your autofill PROBE? Is it in the sightglass or in the boiler? I moved mine around until I decided that the probe worked best in the sightglass. Post some pics if you can so I can get a clear idea of your setup.
How old is the machine? Mine is a mid-80's but given its age it makes some really fine drinks. So don't give up yet, it just may take a bit of trial and error to get things in order.

OK. That makes sense that there must have been an obstruction. Because the noise has not happened again since that one time. I have not run any descaler through the HX. How do I do that?

As far as the pressure, it reads about 5 bar while idle. Most of the time it does not move when while brewing. When it make the noise, it was registering around 10 suddenly. Do you think that means I need to replace the gauge?

Sounds like my machine is of the same vintage. I assumed it was from the 80s. I will try to get some pics tonight and post them.

BTW. I have made some nice drinks on this so far. So I am very please with it considering it was not working at all when I got it. I think at this point its one part fine tuning the machine, and two parts learning how its works.

Please do post some pictures of your machine. I'm just starting to bring back to life a model identified as a PUBSU, and am interested in your experiences.

Been busy this week...glad it's over.

I wouldn't replace your pressure gauge just yet. Sometimes the line pressure along with pump pressure may spike the overall reading. This is where a line pressure regulator can be used, to guarantee a constant feed pressure.

The way I descaled my boiler and exchanger without disassembly was I simply took off the vacuum valve from where it now sits on top of the boiler and poured in my solution throgh that hole. I filled the boiler almost completely and let it partially heat up, then let it sit for less than an hour, as I knew it was already relatively clean. This was just to clean out whatever may have been lurking in there from sitting for a year. I then put the pump inlet line into a jug of solution and ran the pump and flushed the heat exchanger thoroughly and let that sit for a while as well. Then I flushed well with clean water. It's been 8 weeks since I put my Pub into service so I think I'll be doing this procedure in another 4 weeks, as I have no softener system on the machine.

PICTURES??