Need to replace my La Pavoni heating element :/ Any idea which threadlocker to use and where to use it? I don't have to buy a new pstat copper tubing, do I?

I looked up this guide http://www.francescoceccarelli.eu/La_Pa ... to_eng.htm and he doesn't seem to be using any threadlocker though

you don't need threadlocker for the 3-bolt heating element itself,
just make sure you get the right sealing ring (the new steel elements have an o-ring instead of the flat ring used with the older copper heating elements).
You can try to transfer the preasurestat tube, this should be a screw in type for this model, here threadlocker might be needed to get a good seal. I'd only apply it on the last threads and make sure you get the high-temperature resistant version.
cheers,
Rob

Thanks! any recommendations for a threadlocker?

Just did a quick search using the site's build in search function: according to an older thread Need help repairing used La Pavoni Europiccola
this threadlocker should do the trick https://www.espressocare.com/products/i ... h-strength
cheers,
Rob