# Symptom of a faulty solenoid



## RodMB (Jan 17, 2014)

Without wishing to tempt fate I thought I would share my successful fix of a problem for future reference. I've posted before in a previous thread titled 'Problem with Gaggia Classic: flow stops when heats up', but actually I think this is a generic problem that could affect many types of machines.

My own machine is an old Rancilio Nancy, (one of the predecessors of the Silvia), and probably dates from the mid 1980's. Around New Year it developed a problem where no water would come through the group head along with some odd sounds that I assumed were due to pump failure. I made the mistake of rushing to fix the problem before I'd taken the time to really understand what was going on and bought and replaced the pump. Unfortunately this didn't fix the problem and I paid a bit more attention to what was going on and noticed that when the machine was cold, the pump would run and water would flow from the group head. After a couple of heating cycles, (approx 5 minutes from turning on), the pump would run however no water would flow through the group head. I checked and saw that water was actually being pumped through the machine and out through the return hose back to the water tank.

It was all a bit of a mystery and after researching a number of website, including here, I came across information 'more than you ever wanted to know about three-way solenoids' here - http://www.baristaexchange.com/m/blogpost?id=1688216%3ABlogPost%3A990088 I am very grateful to 'Brady' who posted the information, and reading through it I realised that a fault in the solenoid could give the problems I was having with my machine. I think solenoids are generally felt to be quite reliable however given the machine is pushing 30 years old, nothing is guaranteed, and a fault in the solenoid seemed the likeliest cause.

I did strip everything down to check there wasn't a simple mechanical blockage as this could also cause the same problems, (I think this would be one of the main reasons to back flush machines to prevent residue building up in the three-way valve), however in my case there was no significant blockages and I also noticed the machine had started to developed a rapid loud alternating 'clicking' sound from time to time when the water flow to the group head would flow intermittently. I think this is a classic symptom of a faulty solenoid and suspect the problem may well just have related to the age of the solenoid coil.

Anyway I managed to get some advice on replacement parts, (see separate post in Equipment Retailer reviews regarding 'Expresso Underground' - thanks again, Peter), and replaced the whole solenoid and 3-way valve unit.

Happily I'm back in action and the repair seems to be holding up after a week now, so I felt safe to post.

Anyway, I hope this information is of use to someone in the future. Thanks again to others who shared their experiences. I was close to pulling the trigger on a new purchase so I've saved several hundred pounds and the machine has a lot of sentimental value, (an inheritance), so I'm glad it is holding up. I guess I have a spare pump as well - so another lesson is don't rush to fix something until you know what the problem is!


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## 200 Degrees Coffee (Mar 21, 2016)

Great, thank you


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