SteveU, thanks. I’ll check with my rural supplier this weekend. And Michael, yes working under vehicle!
I installed another inkbird in the basement to monitor over temp warning last year for the old boiler but still kept it for the new one. I used an old viberscribe layed on the return duct for the buzzer. The air duct transmits noise somewhat through the house.
Inkbird comes with a button style probe but didn’t work well when taped or insulated with rag onto the pex tubing but worked when taped and wrapped with tin foil. This is for alarm.
Getting back to the boiler. Wiring diagram on inkbird.
As a side note I plan to use an inkbird to monitor the temperature of an alternator for my super capacitor inverter generator, when I can get back to that project.
I was going to make a well for the button style probe to insert into the boiler water but found the small well screw in style on Amazon. I think it is 8mm bolt thread so I drilled and tapped a pipe plug. The inside of the plug I drilled at a larger diameter to allow more water near tiny probe. Made seal washer and also taped threads. Theo the item is the solenoid that lifts the flapper that is an exhaust rain cap.
According to the specs inkbird might have handled the current draw but I installed a relay just for the heck of it.
More later because it is getting late.