This job was in a hotel in Sedro Woolley. A boiler that size could literally explode like a small bomb.
The handyman tried to fix the boiler's recirc piping with compression fittings and pvc fittings. While we were staring at it, the handle on his plastic ball valve melted and shot across the room. I was able to shut off the water, thankfully, and repair it in short order.
This picture is the broken valve.
I didn't take a picture of my repair, but it cost them under $200.00 including parts, labor and tax.