My rear heat is not working.I can feel both heater hoses underneat just before they attach to rear core and where the valve is located. The hose with heater control valve is cold both sides of valve other hose hot. I assume core stopped up. But I was thinking shouldnt the heater control valve hose be hot or not? Not sure which way water passes through. thanks terry

 

That valve can go bad. I believe it is vacuum controlled, so make sure the vacuum line leading to it is in good condition and is connected. A vacuum leak elsewhere in the system could also interfere with normal operation.

 

Should the line heater valve is on be hot. In other words does water flow through heater valve into core?