# Group head bolt



## bronc (Dec 10, 2012)

Does anyone know what the purpose of this bolt is?


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## Kyle548 (Jan 24, 2013)

Got a photo of it?


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## bronc (Dec 10, 2012)

I managed to find two photos (not mine).


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## Kyle548 (Jan 24, 2013)

bronc said:


> I managed to find two photos (not mine).


I think I have seen this used for a thermocouple.

Apart from that, no idea, probably does something though.


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## El carajillo (Mar 16, 2013)

Does it lock in what appears to be the shower plate in the photo??


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## bronc (Dec 10, 2012)

No, it doesn't. What you're referring to should be the part where the boiler and the grouphead join together.


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## espressotechno (Apr 11, 2011)

Remove it, have a peek inside the hole, or poke a long piece of soft wire (opened up paper clip) in & see where it ends up.

It's probably a blanking bolt for a small internal jet/waterway....

PS Some PTFE tape may be required when refitting the bolt.


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## Ran1 (Oct 22, 2013)

That bolt is the cover for what is basically an access chamber. It is removed by engineers to check the chamber if any blockages occur. If you remove the shower and push a small drill bit / allen key up the angled water outlet, you will be able to see it if this bolt is removed. If you push a longer allen key through this hole behind the bolt, you will reach the solenoid valve outlet. It's removed if blockage is scale related or coffee related to allow the acid / puly powder to attack obstruction from more angles. If removing be careful not to lose the copper washer!


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## bronc (Dec 10, 2012)

Thanks! It's good to know that it's there for a reason.


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## espressotechno (Apr 11, 2011)

These bolts, etc are always there for a reason......but usually the reason is evident only to the (Italian) designer who has long gone.....lol


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## bronc (Dec 10, 2012)

I wonder if the hole can be used for a thermoprobe similar to Eric's E61 group thermometer. I'm not sure if measuring the grouphead temperature will be really useful though.


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## espressotechno (Apr 11, 2011)

Yes, provided you can achieve a good watertight seal for the thermocouplecouple nut


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## bronc (Dec 10, 2012)

Will the TC touch the water through the hole or just the grouphead?


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