The exact replacement valve probably isn't available, the tech. could most likely retrofit a new gas valve but could be there most of the day trying to figure it out.What the tech. is trying to tell you it's more trouble than it's worth.Get the name off of the valve and mod.# and call your local heating supply houses and find out if they can get the valve.A vendor made the valve for williamson such as honeywell ,white rodgers,robertshaw etc. the part number probably won't crossreference but you never know.Good Luck

oh been there done that almost blew up the house in the process. If you cant find the part chances are the furnace is way too old and should be replaced. If you get a 90+ furnace you will save money in the long run, but shop around before you do.