Fiorenzato Bricoletta Volante Rotary Direct Plumbed.

Machine has been on 24/7 for about 3 years, no problem up until this AM.

Today was pulling a second shot and the machine started pulsing a relay and the pump started pulsing at the rate that the relay was cycling. The machine filled its boiler then returned to the pulsing.

Powered the machine down, powered back on and the relay below the boiler started cycling at about 1/second.
On/off/on/off etc.
After machine cooled down it still continued this cycling at power on and wont run normally now.

Any ideas? Never had a parts replacement or any other failure. No leaking water inside, no apparent wiring failures etc.

Machine has been direct plumbed RO water since day one, so scaling/calcium is non existent in the system.

Do you mean the heating element keeps turning on/off? I don't know the particulars of the Fiorenzato's internals, but it sounds like the pressurestat is failing (three years of 24/7 operation is nearing the limit of a pressurestat's service life). Well, unless it has a SSR to avoid switching higher current, in which case the SSR may be failing.

It appears that there is a conventional relay that switches the heaters, and that appears as what is audibly clunking (cycling) open close open close. Ill check the pressure stat, just wasn't sure of all the symptoms of a problem pressure stat. I've read the pressure stat failures that lock on, but not necessarily this issue.