My Immersion heaters Ceramic insulators cracked

[artooks]

Hi,

I purchased a new stainless steel immersion heater from Brewpi, it is a 5500 Watt 220Volt heater, today I cleaned it with PBW and finished the wiring it can be run as three phase or single phase with correct wiring. While I was tightening the bolts, I think I over screw it and a very small part from the ceramic insulator has cracked, but I went ahead and test it, and it was working fine, but I still suspect, if anything should be done, before something major happens, or should I just use it as is without doing anything. I need some assistance on that matter, thanks.