Has anyone replaced a Coffee Group Temperature Sensor?

[JonF]

Woke up to lights 20 and 21; Coffee Group Temperature Detection System failure. From the manual, it seems to be an open circuit connection as the water temp was only 40C.

Anyone replace their own? It is under warranty, by the way, so I could ship it back.

Thanks,
Jon

[Endo]

If it's still under warranty, I'd call the retailer and ask about changing it. Since they aren't interested in reselling a used machine and giving you a new one, they will likely help your troubleshoot first. They will start with the light code and follow a "fault isolation" procedure. This will likely start with a check of the basic wiringcondition and move on to more complicated things like checking your thermo sensor for continuity, checking voltage, etc. If it is the thermocouple, you will need to replace it. If you are not handy with a wrench, they will likely ask you to go to a service person near you at their cost (as they don't want you to ship it and risk more damage). If you are handy, you may want to remove the boiler heating element by removing the brass nut on the end of the boiler and sending the unit to them for replacement or repair. You can have look at my blog if you want to see what the sealed thermocouple unit looks like. It's inside the crimped copper tube above the heating element. It has grey wires coming out which are sealed in clear silicone on the endplate.

http://cremina-endo.blogspot.com/2011/0 ... aling.html

[JonF]

Thanks, Endo, for your detailed reply. It is looking like a very easy repair, so a new sensor is on the way. Even if it escalates to the heating element assembly, I think I am covered. Your blog photos were helpful--will keep me from spilling too much water along the way.
Thanks,
Jon

[Endo]

I'm guessing you will pull out the wires along with the silicone plug and replace the thermocouple itself with one they are sending you. If you can, take a picture of the old and new thermocouple. I'm curious to see what is housed inside that copper tube.

[JonF]

Sure thing. I took out the old one already. Here is the culprit:
http://www.chriscoffee.com/products/home/repairparts/s1coffeetempsensor

Just one new concern . . . there were a few drops of water in the tube with the probe. So thinking about replacing this part too. Chris Coffee has been super. I would rather not pack it and return unless really necessary.

[Endo]

I guess the shielded probe fits inside the tube. Though from the picture, it looks like a tight fit.

I suppose it's sealed in the copper tube because the probe is not water-proof? If that's the case, then it seems you would need to replace the outer copper tube as well. I can't remember seeing how the copper probe shield is installed, but from this photo online, it looks like the 800W heating element is sold without it, so I assume it just pulls off somehow. Maybe that's where the leak is coming from?

(Heaters are pricey at $129 in Canada!).

https://www.caffetech.com/parts-accesso ... -7476.html

[JonF]

Greetings!
Chris Coffee sent me a sensor as well as a new sensor tube since I found a little moisture in the old one. While not obvious at first glance, when you clean off the silicone holding in the sensor you find the end is a 5mm hex. So the entire assembly screws out.

If you are just doing the sensor it is really easy. Just pull out the old one, push in the new, and add a little silicone to seal it in. Spent more time getting the side back on than anything.

Now I am running fine, but might have just a slight leak around the sensor tube I replaced. Anyone use thread sealant or anything on assemblies? Perhaps an extra wrap of teflon tape? The leak is so slow that it might also seal itself shut just by mineral deposits. Anyway, not a big deal.

Now to check the offset. I don't have access to a scare, so I will fall back on my single portafilter with thermocouple in a little block of foam. Looks pretty close so far. . .

[JohnB]

Now I am running fine, but might have just a slight leak around the sensor tube I replaced. Anyone use thread sealant or anything on assemblies? Perhaps an extra wrap of teflon tape? The leak is so slow that it might also seal itself shut just by mineral deposits. Anyway, not a big deal.

Teflon tape would probably fix the problem but I always use a thread sealing compound on any fitting that goes into the boilers.

[JonF]

Now I am running fine, but might have just a slight leak around the sensor tube I replaced. Anyone use thread sealant or anything on assemblies? Perhaps an extra wrap of teflon tape? The leak is so slow that it might also seal itself shut just by mineral deposits. Anyway, not a big deal.

Teflon tape would probably fix the problem but I always use a thread sealing compound on any fitting that goes into the boilers.

ah the joy of plumbing--. Just relieved that s1cafe has a bang-head smilie.

I tightened it a bit and it is so slow now I might just see if it seals itself. Thanks John for the suggestion--I will try that if I need to. Luckily, I had not sold my Livia, so brought that into play whilst awaiting the replacement parts.