Heater valve on a National Tropical

Hope you can open this. It is the troubleshooting manual. My valve is located inside the front cap. To access it I have to put the generator out. It is located up in the left hand corner as you are facing the front. Just follow the heater hoses on the inlet side of the heater. You can pull this valve out. There are 2 clamps. You will loose some antifreeze. Turn the key on and have someone cycle the a/c and heat knob from cold to hot. The inside of the valve should open and close. After putting it back together start the engine and put it at high idle and let the engine heat up. After the engine is hot and the switch to hot see if the inlet side for the heater is hot and the outlet side is just as hot. If you have no heat at the inlet valve your valves at the engine might be shut off. www.evanstempcon.com