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Permalink Reply by Mike Sabol on April 8, 2011 at 1:38am

But -- (And I am not paid by La Marzocco to say this) -- Two of the heads have not!  And when was the last time you were really rocking all four groups at once?

 

Part of the beauty of the the 4grp Linea are the redundant coffee boilers and the separate steam boiler.  If you had a heat exchanger machine and the element wouldn't fire for some reason you'd be SOL.  But not in this case.  The elemental issue is that one of the coffee boilers is not heating up.  But... there could be several reasons for that.  First easiest fix is that the overtemp breaker is popped.  Turn the machine off.  Take the front, skinny, silver top cover off top off the unit, the one right in front, above the button pads.  You will see 4 big silver platforms, which are the tops of the groupheads, and the two platforms on the ends will have little devices screwed into them with two wires coming out and a small red button on top.  Those are temperature activated circuit breakers.  The one corresponding to the side of the machine that has lost temperature could be popped.  Press the little red button down.  If you hear if pop or feel it make a definite click then you have found your culprit.  ALTHOUGH... Those things pop for a reason.  It is not enough to simply reset the breaker and continue using the machine.  You can create a dangerous situation by doing so.  Those breakers pop because they think they get too hot.  There is a bi-metal strip housed inside the plastic casing and as the temperature changes it causes the two different metals to expand at different rates, thereby bending the strip out of shape and causing the circuit to be disrupted.  This happens either because the temperature is actually too hot or because the metal in the strip have lost the apppropriate spring tension over the years of service and deform under normal operating temperatures.  The technician would do a simple temperature calibration to evaluate this condition.  If the unit turns off again before the desired temperature is reached then the breaker is faulty but if the unit continues to heat after the desired temperature is reached and the breaker opens the circuit shortly thereafter then the boiler's temperature feedback loop is faulty and the breaker is doing it's intended job.  At that point you have to figure out why the element is continuing to receive voltage even after the temperature set point is reached.  At this point you have to monitor and relate two variables:  You have to continually monitor the temperature of the water in the boiler and then you have to continually monitor the output side of the boiler thermostat for 120vac to determine if the electricity is cut off when the thermostat reaches the desired temperature.  If the switch continues to show voltage at the output when temp is reached then the thermostat is at fault.  At this point you have to test to see if the thermostat is defective or if it is simply misadjusted.  You test this by making an adjustment to the thermostat and then monitoring the temperature of the water to see if the cutoff point has changed accordingly.  If it has, then make the requi...

 

Well, it goes on like that for a while.  If you're interested I can step you through some basic tests on the phone.  Just PM me.  The other thing to check for is that your water filtration system is working properly.  If the machine is starved for water then a boiler can overheat and cause the breaker to pop.  If replacing your filters and resetting the little temperature breaker on the machine doesn't solve the problem then you should call your service tech.

 

Good luck.

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Permalink Reply by Mike Sabol on April 8, 2011 at 2:40pm

I should also add that if the breaker is not popped then you need to figure out why the element is not heating.  There could, again, be multiple reasons for this.  A bad element, a bad thermostat, a disconnected wire...  Several conditions can lead to your situation.  Some are easy fixes and some are major surgery.

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Permalink Reply by Graeme Duhamel on April 10, 2011 at 9:42am

Thank you very much this information was very helpful

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Permalink Reply by Mike McGinness on April 10, 2011 at 10:25am

It happened before; was it the same two groups, same boiler (left or right) not heating? If it's the same I'd wager the root cause may not have been correctly diagnosed and corrected last time. I'd call and try and find out exactly what was done the last go round. If the same boiler and not too long ago I'd push hard for a repair warranty service call.

As far as rocking all four groups at once goes the problem is if not alternating your pulls between the two brew boilers during production brew temperature dives FAST. Any decent barista will easily out pace the brew boiler recovery time on a four group Linea using just one side. (or two group, same boiler/heating element) But yeah the good thing is not totally down.

 

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