E61espresso machine repair

 

E61 machines are the affordable espresso machines to those willing to invest time to make a good cup. These are serious semiautomatic machine from Italy that are similar to what are used in cafes but at home baristas' budget. Unlike most consumer machines which are disposable, these can be repaired and rebuilt indefinitely. While each brand and model are different the parts are generally generic and can be procured readily. It is the nature of the business of heating water and making steam that inevitably they will need maintenance and repairs. I had repaired it once before due to the failure of a solenoid valve's magnetic coil.

Mine is no exception and after a few years of use, the machine stop working. I had tried to debug it a couple of times looking for the obvious only to be disappointed. As they typically don't come with service manual and each model is different in design and implementation it is like trying to service a car without service manual. There is no schematic or plumbing diagram.

Fortunately for me the knowledge and skills of automobile are transferable to this espresso machine repair. The key is to give myself time to study the machine over and discover how it works. 

the inside of the machine is quite intimidating for the uninitiated; but for me the only way to learn is to break out the hand tools and dive right in

one thing that I tried was to infuse the boiler with a citric acid water mix hoping to open up a clogged passage

it turned out there were double faults - a clogged small diameter passages both at the rotary pump

this is a metering jet for the outlet of the pump; I cleared the clogged passage with a needle

the easiest mistake of debugging this kind of machine is to accidentally let the heater to come on with a empty or incomplete submerge heating element; replacing the heating element will necessitate a complete removal of the boiler tank which is something you want to avoid if at all possible

debugging it electrically hot is also a safety hazard so one need to be systematic and proceed with a clear head

the green tint of the water was due to the citric acid solution removing some copper oxide

after the pump ran for a while the full concentrated citric acid solution was flushed out from the boiler

once I invested some time studying closely the wiring and the function of each part I gained more understanding of how the machine operates

finally the boiler was building pressure

before buttoning up the machine I carry out a test of making a double ristretto

as I had not use this machine for a couple of years I have to relearn the technique and ritual

this is a plumb-in machine

it took a couple of days for me to dial in the grinder setting as well as the barista skills of using this set of equipment

all cleaned up and ready

it is such a pleasure to have a cup of espresso after a good homemade meal especially an Italian dish

Speaking of plumbing, I have one more plumbing problem to take care of. This flex copper hose at the outlet of the on-demand water heater developed a leak as the weather has gotten so cold. I was reluctant to break into it without having a spare replacement on hand. I pondered on should I attempt to repair it without first going to the store and buy a spare in case I need one.

the drip created a big puddle on the floor in the room where the well accumulators are

However looking at the piece joining together I suspect the rubber gasket inside is either been distorted or over compressed. Since I can switch off the water supply to it I figure it is worth a try to remove the hose and investigate.

As soon as I unscrewed the fitting I could see the problem. Someone use teflon tape on the threads of the fittings on both ends of the flexible hose. These fittings do not require thread seal as the sealing is done by the rubber gaskets. Adding teflon tape to the threads is not just redundant, but prevent the tapered threads from fulling engaging to allow the seals to do their job.

I cleaned off the last trace of the teflon tape, and smeared on some mineral grease to lubricate the thread. Within minutes the leak is repaired, without the need to spend a cent.

here is one photo I found on the web by a "professional" which is clearly a failure of him to grasp how these most common joints function