The Original
It's A Grind

 
 

Commercial Brewer, Espresso machine and Grinder
Troubleshooting tips and information

Updated 7-6-08

General Information

    Espresso Machines
        General Info
        Installation Tips
            Placement
            Water and electrical supply
            Drain
        Troubleshooting
            For generator operated mobile units - be sure your output is at least 210v under load for 220v units.

    Bulk and Espresso Grinders

    Coffee Brewers

Service Tips by make

    Brasilia

    Bunn

    Fetco

    Wilbur Curtis

    Mahlkonig

    JH Mckie and TJ Topper urns
        These ancient workhorses can easily be maintained still.
            The heating elements are common replacement units usually available locally through Grainger or Johnstone supply. Same with the thermostat.
            Faucet and sight glass parts are often common parts also with the exception of the glass, which may be difficult to find in those lengths and the sight glass seals which are different. If they ain't broke, don't break them!!!
            Liquid level controls are easy to come by, and Bunn 7074 control boards are easily adapted, and available in 110 and 220 volts.
    Timers. I haven't had to by a timer in quite a while. Mechanical timers were quite common at the time, giving me hope that something might be availible. If not, a moder digital timer could be adapted.
 
 
 

Grinder Tech New!
FAQ's
    Commercial Espresso machine general installation guidelines
 

Technical Information
Service secrets

FAQ's
How often is my Espresso Machine going to require service?
Like most things, it depends.
Generally, "portafilter seals" require changing about every 6 months. Many filter systems require changing every 3 or 6 months, And so, service intervals are set at 6 months, while I'm there I'll operate the machine to check for correct function, check for steam leaks and correct pump pressure, evaluate the shot timing. Most water filter systems are designed to be changed at 6 month intervals so I can change the water filter or  charge the water softener while I'm there.
What causes it to wear out so quickly?
Heat is both our friend and enemy in the coffee biz. we use the higher temperature to more quickly extract the espresso, steam milk for an endless supply of lattes.
I believe that one of the first mistakes people make is to crank up the boiler pressure, generating greater steam capacity, but at the same time causing accelerated wear and the expense of maintaining a higher temperature.
Should I turn the machine off overnight?
It's easier on the machine for it to stay hot than to be cycled hot and cold regularly. In some cases when the machine is not working correctly, or unattended, it may be advisable.
What most often breaks?
Because of the heat, rubber parts are the most vulnerable. Generally, portafilter seals, steam valves, sight glass seals and vacuum valves.
(unless of course you like to do your own repairs in which case you will probably be responsible for whatever breaks.)
Steam leaks are very common and often accompanied by electronic faults.


Finding steam leaks.

Often you will find water condensing on surfaces near the leak. Above the leak, under cup trays, discoloration, rust. If a steam nozzel is leaking, drips from the nozzel on water on the drip tray underneath.
Use a two or three foot section of drain hose to pinpoint leaks. This old mechanics trick of holding one end to an ear and probing around with the other, works well.
Fixing steam leaks
Remember the basics.
This is ALWAYS the result of higher pressure trying to equalise w/ a lower pressure. (Usually to atmosphere in in espresso machines, but not always.)

Some engineer incorporated a method for preventing this equalisation and there is a groove in it, that isn't supposed to be there.

Repair THAT surface.
 

In the USA, we generally have 3 types of fittings used in plumbing or low pressure boiler applications.
Pipe fittings in the USA are a tapered, interferance fit.

Flare fittings have a "flared" or trumpet like end which makes the seal, and a nut that fits over it which secures the assembly. This is superior seal to the compression fitting, unfortunatly it requires some modest skill and commonly availible tools. I'm told the local plummer gets 15 minutes for this proceedure. I fantasize about a job where I could do this all day and get paid $15 for each one.

Compression fittings incorporate a ferrule that slides over the outside, near the end of the tube and squeezes the tube to form a seal while the retaining nut is being tightened. This type of seal is more common to leak as in there are now two places it can leak past the ferrule.

Only espresso machines made in the USA use these type of fittings and not all.

Made in Italy should be your first clue.
European pipe fittings are parallel thread and often have a seal or tip fitting to the end of the pipe which makes the seal,
or use a HARDENING pipe dope to form a seal AND hold the assembly rigid. Teflon tape is often used,and works, but doesn't do a good job of holding the assembly rigid.
"Expando" pipe joint compund is a domestically availible hardening compound that works well. (requires  24hr setting time.
www.xpando.com


European flare fittings are pretty similar to US units. and, if damaged, a pipe can often be shortened slightly and reflared. The male end of this paring can be more difficult. The rear housing of a steam or water valve can be recut in a lathe, or for field repairs, a soft copper seal can be inserted over the defective male flare.

Using teflon tape for this type of repair is temporary at best.

Compression fittings are also used frequently as well as variations including ball and nipple ends. Ball ends are typically used to attach flexible S/S braided or rubber water lines.
Overtightening these fitting will split the male threaded recepticle for the ball and the more you tighten it, the more it will leak.


 

Many good reasons not to neglect steam leaks!!!

  • Safety A leaky steam valve gets and stays VERY HOT.  Can easily burn yourself handling the wand or working near it. The health department HAS written people up for it. (At least one inspector who burned himself did.)
  • Make better espresso  Many components of the heating system and boiler work together to ensure your coffee is being brewed at the proper temperature. A steam leak makes the pressostat think the boiler isn't at operating temperature and so increases it.
  • Use less electricity because the heating element is cycled on less frequently
  • Corrosion A constant jet of steam will destroy many types of finishes, which once begun, becomes more and more difficult to rectify. More importantly, damage to the chassis can literally cause the boiler to come loose inside the machine become unstable enough as to disable the machine or create a serious safty hazard.
  • Avoid Short circuits and expensive electronic repairs

    • Tips:
         Portafilters and baskets should  NOT soak in CLEANER overnight and it is recommended that care is in order because too strong a solution can cause the disintegration of plating and other materials.

     A client asks about hooking the machine to a hot water source to reduce heating costs.
    Bad idea. Most machines are designed to be hooked up to COLD water. Your expensive Procon pump is actually cooled by the cold water flowing through it. Most inlet valves  are designed to be used with cold water and will self destruct if exposed to very hot water. Many types of water line are NOT designed for hot water.
    Never use a centrifugal start "carbonator" motor to replace a capacitor start espresso machine pump motor.
    It doesn't work. It'll last about a year before it burns up the motor relay on the expensive electronic control board. I found out the hard way. Don't you.


    Rebuilding carbonator or Procon pumps

    I know a company that USED to do it. I doubt there was lack of demand.
    Procon also sells rebuilt units.
    Cleaning screens
    Not all machines are DESIGNED to have the screens removed daily or weekly. Sometimes the PF seal is destroyed while removing the screen and must also be replaced.

    I am NOT of the opinion that screens should be removed to be cleaned. Certainly not daily or even weekly. Twice now in a month people have brought machines to me in which the steel retaining bolt has destroyed the soft brass threads in the group head.

    Proper back flushing does a fine job. I've serviced machines under extreme use and w/ proper backflushing, the screens can look almost new.
    Technical Information
    Programming Instructions
     
    Coffee Brewers
    Bunn - Digital timers

    Curtis - Digital timers
    Espresso Machines
    Astoria/CMA/Mr Espresso
    Brasilia
    Faema
    Pavoni
    San Marco



    Service Tips
     
     
     

    Brasilia -

         The one older 1 group machines typically have a fairly small boiler, making quick recovery essential.
    Many of these machines use a small a supply tube to the steam valve which is unable to provide full - continuous boiler pressure to the steam nozzle. This further reduces the effectiveness of the steam wand.

        The supply tube to the pressostat easily becomes plugged because of it's small size and becomes slow to respond (or fails to respond at all) to rapid changes in boiler pressure, such as when the steam valve is opened.
    This can cause dangerous over-pressurization. Recovery time suffers when the pressostat opens later.

        The solution to both problems is to replace the existing tubing with that of a larger diameter.

        For the steam valve, I drilled out the existing flare nuts to accept 1/4 refrigeration tubing, formed a length of tubing to fit, and flared the ends to fit over the existing european flare fittings. 5/16" tubing would have been a better choice but isn't as common. At the same time, drill out the boiler fitting for the steam valve supply tube to a larger diameter.

        The solution for the pressostat supply tube is more straight forward.
        A 1/8" female pipe x 1/4" male flare adapter is fitted onto both the pressostat and boiler supply fitting, using standard 1/4" flare nuts and copper tubing to connect the two.

    Pesky leaks from the cold water inlet to the heat exchanger can be solved by retapping the 1/8" euro/parallel pipe threads to a standard 1/8' tapered pipe thread, thereby getting an extra turn or two of rotation and an interference seal.

    Service life of the Optical Flow Meter is extended when the Check Valve and Expansion Valve are working and adjusted correctly.

    Ceramic Steam Valves - Don't seem to last more than 6 months under normal use. A properly rebuilt ceramic steam valve lasts about 6 months under normal use. If you're as tired as most people are, of changing and rebuilding these things, there is a conventional "old fashioned" replacement available for about the same price, which has a much longer service life.

    "Small" Steam Valves.........have sometimes been replaced with the full size valve of the same vintage. I think this is a mistake. The conversions I've seen have been poorly done because the valves are simply too large to fit in the existing space. It's just not worth it to permanently disfigure a machine to fit a valve that is hardly an improvement. The small valves are easy to rebuild or replace. (tip: when rebuilding these valves, always check the length of the return spring)


    Espresso Top 50
    ©1997-2008 It's A Grind
     All Rights Reserved