I was quickly comfortable working with Matthew on my system. He was logical in his approach and suggested a range of cost depending on how things went, which included locating a valve that wasn't working and others that I didn't know where they were. I now know where all but one is but still have one dead zone that couldn't be located. He theorizes that the valve is on of the oldest in my system like one other but this second one too, though working for now, appears to be failing. I now face a need to pay an additional amount to install heads onto an existing working zone as the best way to deal with this.
I think the overall cost is a bit high and at a bit higher than originall estimated, but compared to other estimates I was given, it was reasonable and the work performed was excellent.