I appreciate the response.
Tell me... am I asking too much of the new fancy "smart" digital water meter then? Because from time to time I'll check it to tell me if there are any leaks. I do that by ensuring nothing is (deliberately) running, then I activate the meter (you shine a flashlight at the sensor so the display turns on) and it shows me that the flow is 0.000000 cubic meters per minute. So for it to not detect a leaky shut off valve, the flow would have to be extremely minimal, or its just not as sensitive as it appears (6 decimal places... let's see, that's 1/1000th of a litre in a minute).
And now that I think about it... it would have to be two faulty shut-off valves.
Its plumbed like this: we're in Canada so the pipe comes in from the ground beneath the house. I have a main shut off there. It then goes to the mechanical room where there's another shut off just before the meter. From the meter it branches with one going to the PRV and then the rest of the house while the other goes to the double check valve. After the check valve is the first irrigation shut off and then it goes about 15 feet and exits the building. Immediately outside there is another irrigation shut off. From there it goes to the valve box, etc.
Both shut offs are closed for the winter (inside first, then system blown out, then outside is shut)
I've been reading on
http://www.irrigationtutorials.com/ and making my way through that trove of info. I'm learning that there are a million ways these systems are designed. From what I'm reading (there and here), it seems rather unusual for the check valve to be inside the house? It also seems rather unusual to have two shut offs, right?