My heater valve does not work, it is always open. Rudy said he could sell me one, but that I could fix it myself with parts from NAPA. When I took it out, it appears that rotating the switch on the outside, does not close the valve, but I can manually close it by pressing the inner spring-loaded switch up. I'm not sure what the problem is or what parts NAPA would supply, but when I went there today, they only came up with what looks like one gasket, I really don't know where it would go or how to replace it. It also seems like I need more parts to make mine work correctly. Has anyone rebuilt one of these and knows the NAPA rebuild number, and how to go about rebuilding it? It's a 53K if that makes a difference.