auto fill ver: shutdown

I am not convinced on using an auto fill for a hydronic system.
With a fill line connected all the time you could have a small leak for a long time before finding out.
What if using a switch that upon low pressure would shutdown the system via the AC feed?
What would be the name of such a pressure switch?

we have been using auto fill valves for close to a hundred years now with very few problems.

A boiler that didn't have a low-pressure shutoff probably wouldn't pass the required safety tests. Just what you need if you're out of town and the heat shuts down. I'd feel safer with a small leak and the heat stayed on verses a shut-down system, or one where that switch failed and it flashed to steam, maybe messing other things up as well. I think an autofill is the lesser of two evils...

I have a unique situation.
I don't have a boiler but run a heating box with a tankless hot water heater.
As for having the heat shutdown while out of town probably isn't a concern where I live. It rarely gets below freezing here.
My thoughts are if the pressure goes down I shut off the pumps, saving them.

rrekih said:

I have a unique situation.
I don't have a boiler but run a heating box with a tankless hot water heater.
As for having the heat shutdown while out of town probably isn't a concern where I live. It rarely gets below freezing here.
My thoughts are if the pressure goes down I shut off the pumps, saving them.

Click to expand...

Put a low water cut off in the system.