Originally Posted by Edwards Htg & Clg
Don't think anybody used them in '91. Seems like they showed up in '95 or there abouts. Plus the smart valves also had a pilot.
This is true.
Karst means cave. So, I search for caves.
yes, the earlier smart valves had a pilot , but now take the q3400 ignitor & sense assembly
2 hot 2 cool