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Gaggia v2 pid temp sensor location

2.6K views 7 replies 3 participants last post by  Roomanald  
#1 · (Edited by Moderator)
Where is the best place to connect a k type or pt100 temp sensor to the new classic? I tried to find it a home touching the top of the boiler but the temperature reading was about 30c lower than the water temp and didnt react very quickly to changes.

Unfortunately both of the sensors i have are not a straight swap for the original button stats on this version of the classic. Any ideas?

Sorry if this has been covered - I am sure its probably here somewhere but i can't find it using the search.
 
#2 ·
It appears that the standard thermostats on the V2 model are just clamped to the boiler (rather than mounted with an M4 screw like the old version).

However it looks like the clamp holding the stats in place is attached using an M3 set screw.

If it would help then I can provide a pt100 sensor with a brass M3 screw thread that should fit the hole where that clamping screw goes.

I can't be sure that it'll be perfect - but it looks to be closest in location to the position of the standard stats.
 
#3 ·
Thanks for the quick reply . I might try wedging it under the clamp holding the stats first. I think it also holds the thermal fuse in place so seems a sensible place. If that doesn't work I'll take you up on the m3 sensor idea.

Thanks
 
#4 ·
So, i just tried the pt100 wedged under the clamp holding the stats on. It seems to show a temp of around 95c once the machine has settled and obviously fluctuates a bit. Only thing that worries me is that the light goes on on the machine when the temp hits 70c. Which seems far too early. Is this normal ? Or is my sensor just very slow to react?
 
#5 ·
Update:

I installed the pid and went for the k type sensor with the sleeve removed so that just the bead is showing mounted just underneath the thermal fuse on the top of the boiler.

This seems to have worked. However, even with the most aggresive pid settings the boiler doesnt seem to heat enough during a shot. The heat still drops by about 10c. Am i doing something wrong?
 
#7 ·
_shakeyjake_ said:
Does your PID have an autotune feature?
Yes. And I'm using very similar settings as the guy in this post

https://www.google.co.uk/amp/s/amp.reddit.com/r/Coffee/comments/20jre7/how_to_pid_a_gaggia_classic_the_right_way/

Could it be that my sensor location is too close to the cold water inlet and hence it senses the change more than expected?

Correction to the above temp drop of 10c its actually more like 20c. It goes from 97 to 77 over the period of a 30 second blank shot
 
#8 ·
I think I have found the issue and created a much bigger one in the process.

The bead wasn't as firmly connected directly to the boiler as i thought it was. To solve this i thought id slightly unscrew the thermostat holder and jam it under the unused stat. Only thing is the screw seemed to be made of nothing more than dust. It disintegrated as soon as i touched it leaving half of the screw in the boiler.

Any ideas on the best way to remove the broken screw? Taking into account the incredibly small working space.