Problem with old Bezzera

Greg41

I have an old 2 group commercial Bezzera that i am using as a backup for my mobile coffee business.It has sat in my shed for nearly a year now with no use.I decided to give it a run today.first problem: the left group does'nt work at all. 2nd problem.the right group works but the coffee is coming out pale with no crema. I tried 2 different blends of coffee one stale one fresh and still no crema.
Tried the same coffee on my domestic machine and great crema. Any light on this anyone.

mininova

Hi Greg, Could be a few things. Regarding the left group issue I suspect it is a sticking solenoid due to storage. Each group has individual solenoids to control water flow and think water deposits have "gummed-up" the one on the left group. This can be either replaced or serviced depending on your abilities or it might even come good again with time (part no. 700253_22 from Coffeeparts.com.au) The pale crema issue can be caused by inadequate pump pressure, low temperature or a combination of the 2. Firstly, make sure the machine is has been on for more than 30mins and leave idle for another 20 or so. Check correct boiler pressure (should read >0.8) on the machine and run water through the group to see whether the water is hot. Being idle it should initially spit and splutter with quite a bit of steam due to the super heated water left in the HX lines. If not then you have a temperature issue which could be caused by sticky pressure stat contacts, perished pressure stat diaphragm or scale in the coper line feeding the pressure stat. Best bet would be to just replace the pressure stat with a new one (part no. 616597 from Coffeeparts.com.au) checking for scale in the copper line while your at it. Low temperature might even be caused by scale build-up/corrosion on the heater element especially if the boiler was not properly drained before storage. Again this may or may not come good again with use/time. Pump pressure can be checked from either the gauge on the machine if it has one or a porta-filter gauge. Both should read higher than 8.5 bar. Please remember that if you attempt any self repair to use extreme caution as machines have nasties such as lethal voltage, high pressure and boiling temperatures. Hope you get it sorted. DJ

Greg41

Thanks for that info DJ. All sound feasible. I'll try it again and leave it on longer like you mentioned and see how it goes. i'll try it regularly and see if i can wake the old girl into action. failing that i would like to have a go at servicing myself due to funds(lack of) and distance from a service agent. Again appreciate your input and parts info. DJ. i'll keep you posted. Greg.

nzroaster

Greg, there is a service agent locally. Let me know if you need him.