My vented Hunter gas fireplace insert is no long serviced by any dealers in my area so I was looking at a $3000 replacement cost for a new insert, owing to a bad solenoid (hypothesized — but it was 30+ years old). Fortunately the gas control module, made by RobertShaw, was replaceable. After a few hours, with a few wrenches and gas sealant tape, our old gas insert was working flawlessly. Easy to install? A bit tight of a working area, and lots of stuff to disassemble and reassemble, but overall the modular design made the swap straightforward.