Hi Everyone -

I've had my Alex Duetto II for over 4 years now, and I got an A2 error recently. I purchased the sensor https://www.chriscoffee.com/Temperature ... el-237.htm from Chris Coffee, but I can't for the life of me remove the old coffee boiler sensor. Me and my dad were literally sweating trying to get this thing off with no luck no matter what kind of ratchet wrench we used. It looks like the washer may have melted onto the nut.

Any advice on getting this nut off?

Thanks!

Ryan

I've been through this repair. They used a brass washer for some reason, and yeah, it's a real bear to remove. I feel for ya! You may have to heat it to get the metal to expand. I'm not the best person to give advice on stuck bolts though, so hopefully, you'll get some other ideas. However what I did was first remove everything else from the top of the boiler, then I grabbed the best fitting and largest handled open end wrench I could find (iirc, it's 17mm). I wedged a hooked brake tool (yeah, from fixing car brakes) between the boiler and the case toward the front. It allowed me to stabilize the boiler from flexing at its base while I torqued the sensor nut as hard as I could...and that did the trick!

A word of caution...be careful with the resettable safety switch (it's got a tiny red button with two wire posts). The shaft on that one is pretty thin, so it's easy to snap it off, and then you need a screw extractor to get it out.

Once you do get it off, you can install the new one without the stupid washer, just give it 1 - 1 1/2 turns of Teflon thread tape.

Good luck!

I understand that you are getting the error code which indicates a "bad" temperature sensor BUT keep in mind that a poor connection between the sensor and the GICAR PID could also possibly trigger this code. The sensor is a 50K ohm negative temperature coefficient (NTC) thermistor and thus should read 50K ohms at 25 degrees C. The sensor most likely has a quick disconnect between it and the GICAR. Check this for a solid connection.
Undo the quick disconnect and measure the resistance of the sensor.

More later.

emradguy wrote:I've been through this repair. They used a brass washer for some reason, and yeah, it's a real bear to remove. I feel for ya! You may have to heat it to get the metal to expand. I'm not the best person to give advice on stuck bolts though, so hopefully, you'll get some other ideas. However what I did was first remove everything else from the top of the boiler, then I grabbed the best fitting and largest handled open end wrench I could find (iirc, it's 17mm). I wedged a hooked brake tool (yeah, from fixing car brakes) between the boiler and the case toward the front. It allowed me to stabilize the boiler from flexing at its base while I torqued the sensor nut as hard as I could...and that did the trick!

A word of caution...be careful with the resettable safety switch (it's got a tiny red button with two wire posts). The shaft on that one is pretty thin, so it's easy to snap it off, and then you need a screw extractor to get it out.

Once you do get it off, you can install the new one without the stupid washer, just give it 1 - 1 1/2 turns of Teflon thread tape.

Good luck!

Thanks for the suggestion Ron. I can't believe how tight it is on there :-/. Hopefully I will get it resolved this week.

erics wrote:I understand that you are getting the error code which indicates a "bad" temperature sensor BUT keep in mind that a poor connection between the sensor and the GICAR PID could also possibly trigger this code. The sensor is a 50K ohm negative temperature coefficient (NTC) thermistor and thus should read 50K ohms at 25 degrees C. The sensor most likely has a quick disconnect between it and the GICAR. Check this for a solid connection.
Undo the quick disconnect and measure the resistance of the sensor.

More later.

Thanks Eric. I wish I had seen your advice earlier sine I already cut the old wire to fit a wrench around it. I'll look to check there sign next issue that pops up.

If you find that the thermistor is, in fact, bad then . . . use a 6 point 17 mm socket and an electric impact wrench to remove the thermistor sensor.

Install the new temperature sensor with a new copper washer using a normal combination wrench.

Thanks everyone for the help!

The electric impact wrench did the trick. Thankful my dad had all the tools

Best -

Ryan